Cancer Glossary

Overview

This glossary explains 748 words that you can see in cancer reports, test results and conversations with your care team. Each entry gives the word, how to say it (when a pronunciation is available) and what it means in plain language. "See also" points to a related entry in this glossary. Words are in alphabetical order. No entries start with J, Y, Z or a number.

A definition tells you what a word means in general. It does not tell you what it means for you. Ask your doctor or nurse to explain any word in your own report. For the main ideas behind these words, see What Is Cancer?, Genes and Cancer and Can Cancer Be Cured?

Questions to Ask Your Doctor

• Can you explain the words in my pathology report in plain language?
• What is the exact name of my cancer, and what is its stage or grade?
• Which words in my test results are the most important for my treatment?
• Can you write down the names of my treatments and medicines for me?
• Where can I find reliable explanations of the terms you use?

Jump to a Letter

A · B · C · D · E · F · G · H · I · K · L · M · N · O · P · Q · R · S · T · U · V · W · X

A

abdomen [AB-duh-men]: The belly area, below the chest and above the pelvis. Organs here include the stomach and the lowest end of the esophagus, the small and large intestines, the liver, the gallbladder, the spleen, the pancreas and others.

ablate [ab-late]: To destroy an organ or body tissue, or to stop it from working. See also: ablation.

ablation [a-BLAY-shun]: Destroying or taking out all or part of a tissue or body part, or making an organ stop working. Surgery is one way. Drugs are another: for example, medicines that stop the ovaries or testicles from making hormones count as ablation, the same as removing those organs. Heat, freezing and chemicals can also ablate tissue and tumors. Also called: ablative (ab-LAY-tive) therapy.

abscess [ab-SES]: Pus that has collected in a tissue, an organ or another part of the body.

absolute risk [ab-so-loot risk]: The chance that a person gets a disease, such as a type of cancer, within a set period of time. It is given as a fraction or a percentage. For example, a man in the US has an average lifetime absolute risk of colorectal cancer of about 4%. This means that about 4 men in every 100 will get colorectal cancer during their lives.

acquired mutation [uh-KWY-erd myoo-TAY-shun]: A change in DNA that starts in one body cell after birth. Every new cell that comes from that cell has the same change. Sometimes these changes can lead to cancer. Inherited mutations are different: they are present from birth in almost all cells. Parents do not pass acquired mutations to their children.

actinic keratosis [ak-TIH-nik KAYR-uh-TOH-sis]: A rough, raised patch of skin that can form after much time in the sun. These patches are not cancer, but over time a small number can turn into squamous cell cancer. They often occur on skin that gets a lot of sun, such as the face, scalp, neck, forearms and backs of the hands. Also called: solar keratosis.

active surveillance [AK-tiv ser-VAY-lents]: Close watching of a patient's condition with no treatment. The patient has certain exams and tests at regular times. If the results change, the doctor may recommend treatment. This approach can be part of the plan for some cancers, such as prostate cancer.

adenocarcinoma [A-deh-noh-KAR-sih-NOH-muh]: A cancer of glandular tissue. Glands make a substance and release it. Two examples are breast tissue, which makes milk, and the gland cells of the prostate, which make seminal fluid.

adenoma [A-deh-NOH-muh]: A non-cancerous growth of glandular tissue, the tissue that produces a substance. Examples: in the breast, the ducts and lobules produce milk; in the prostate, gland cells produce seminal fluid.

adenomatous polyp [ad-no-muh-tus or ad-uh-NO-muh-tus pa-lip]: A growth made of abnormal gland cells. It is not cancer, but it can turn into cancer, so doctors usually take it out when they find it. The colon can have 3 kinds of adenoma: tubular, villous and tubulovillous. Their cells have different arrangements. The kinds overlap, so a single adenoma can show features of both the tubular and the villous kind. Related terms: polyp, glandular tissue.

adhesions [ad-HEE-zhunz]: Scar tissue that can form after surgery or an injury. When this tissue tightens, it can join organs that are normally separate. Sometimes this causes problems, such as a partial or full blockage of the intestine.

adjuvant therapy [ad-juh-vunt]: Treatment given in addition to the main treatment. Usually it means hormone therapy, chemotherapy, radiation therapy or immunotherapy given after surgery, to improve the chance of a cure or to keep the disease under control. Compare to: neoadjuvant therapy.

advanced cancer: Cancer that has moved beyond the primary site, where it started. If it has grown past its starting body part but has not reached other parts of the body, doctors call it locally advanced. If it has reached other parts of the body, they call it metastatic.

advance directive: A legal paper in which a person states, ahead of time, the health care they want if they lose the ability to decide. Their providers and family can read it. It can cover whether to start life-sustaining treatment, or when to stop it. A second kind names a person who will decide for them if they cannot.

aggressive cancer: Cancer that forms, grows or spreads fast.

AJCC Staging System: The staging system of the American Joint Committee on Cancer. It uses the TNM system to show how much cancer there is and where it is in the body. T gives the size and location of the tumor and whether it has grown into nearby areas. N tells whether the cancer has spread to nearby lymph nodes. M tells whether the cancer has metastasized (spread to distant parts of the body).

allele: One version of a gene. For a given trait, a person gets one allele from each parent, so most people have 2 copies of each gene. Some alleles are dominant and some are recessive.

• Dominant allele: one copy is enough to give the dominant trait.
• Recessive allele: two copies are needed to give the recessive trait.

allogeneic stem cell transplant [A-loh-jeh-NAY-ik]: A transplant of a donor's bone marrow or stem cells. The donor's tissue type must closely match the patient's. The donor can be a relative or a stranger. The new cells take the place of blood-forming cells that disease or cancer treatment destroyed. See also: stem cells.

alopecia [al-o-PEE-shuh]: Loss of hair. It can affect the scalp, body, eyebrows, eyelashes and pubic hair. It often occurs with chemotherapy or radiation therapy. In most people, the hair grows back after treatment stops.

alpha blocker [al-fuh]: A drug that relaxes smooth muscle. Doctors sometimes give it to men who have difficulty passing urine because of benign prostatic hyperplasia (BPH). It improves the flow of urine and blood.

alternative medicine: Treatment that is unproven or shown not to work, used in place of standard, proven care. Examples are special diets, some herbs or supplements and very high doses of vitamins. The American Cancer Society advises talking with your cancer care team before you try one. Some can cause serious or even fatal side effects. With others, the biggest danger is missing the benefit of standard treatment. See also: complementary therapy.

ambulatory [AM-byou-luh-tor-ee]: Walking, or able to walk. An ambulatory care center treats outpatients, who go home the same day and do not stay in a hospital overnight. These centers often do short treatments and procedures.

Amsterdam criteria [am-STIR-dam cry-TEER-ee-uh]: Criteria that doctors use to find families that may have hereditary non-polyposis colon cancer (HNPCC). Some people with HNPCC do not meet these criteria. People who do meet them may want to think about genetic testing.

analog [an-uh-log]: A substance that is close to another one but not the same. One example is a version of a natural substance that is made in a lab. See also: luteinizing hormone-releasing hormone analogs or LHRH analogs.

anastomosis [uh-NAS-toh-MOH-sis]: A procedure that removes a diseased part of a tube-shaped body structure and joins the healthy ends together again.

androgen [AN-druh-jen]: Hormones that both males and females have, but at much higher levels in males. People often call them male sex hormones. Testosterone is the main androgen.

anecdotal report [an-neck-DOE-tul]: A report about one patient or a few patients, based on personal experience. It does not give a full description, and it is not a scientific study result.

anemia [uh-NEE-mee-uh]: A condition in which the red blood cell count is low.

anesthesia [an-es-THEE-zhuh]: Loss of feeling caused by medicines or other substances, given so that patients do not feel pain during surgery or other procedures.

• General anesthesia makes you unconscious (a deep sleep), so you do not feel pain.
• Local or regional anesthesia makes only one area numb, so you do not feel pain there.

anesthesiologist [an-es-thee-zee-AHL-uh-jist]: A doctor who specializes in drugs and other agents, such as gases, that block all feeling, cause deep sleep or relieve pain. Usually this doctor works during surgery.

aneuploid [AN-you-ploid]: See: ploidy.

angiogenesis [an-jee-o-JEN-uh-sis]: The growth of new blood vessels. Some cancer treatments block angiogenesis. This helps stop blood from reaching ("feeding") the tumor.

angiography [an-jee-AH-gruh-fee]: A test that puts contrast dye directly into a blood vessel that leads to the area of interest. Then a series of x-rays shows the doctors the blood vessels around a tumor.

angiosarcoma [an-jee-o-sar-KO-muh]: Cancer that starts in the cells that line blood vessels or lymph vessels.

anorexia [an-uh-REK-see-uh]: Loss of appetite. The cancer itself or treatments such as chemotherapy can cause it.

anterior [an-teer-ee-yer]: At or close to the front.

anti-androgens [an-tee-AN-druh-jens or an-tie-AN-druh-jens]: Drugs that stop the body from using androgens (male hormones). They are pills that are taken up to 3 times each day. To help treat prostate cancer, they are usually given together with orchiectomy (surgery) or LHRH analogs (medicines).

anti-angiogenesis agent [an-tee-an-jee-o-JEN-uh-sis or an-tie-an-jee-o-JEN-uh-sis]: A drug that stops a tumor from making blood vessels, so the tumor loses its blood supply.

antibiotic [an-tee-by-AH-tick or an-tie-by-AH-tick]: A drug that treats infections caused by bacteria and other germs.

antibody [AN-tih-bah-dee]: A protein that immune system cells make and release into the blood. Antibodies protect the body against foreign agents, such as bacteria. The body makes them in response to antigens, which are substances that cause a specific immune response. Each antibody can destroy only one specific antigen.

anti-emetic [an-tee-ih-MEH-tik or an-tie-ih-MEH-tik]: A drug that prevents or reduces nausea and vomiting.

anti-estrogen [an-tee-ES-tro-jen or an-tie-ES-tro-jen]: A substance, such as the drug tamoxifen, that stops cells from making estrogen. Anti-estrogens treat breast cancers that need estrogen to grow, and researchers are studying them for other cancers. An anti-estrogen is one type of hormone antagonist. Also called: estrogen blocker.

antigen [an-tuh-jen]: A foreign substance that triggers the immune system to make antibodies. Bacteria and viruses carry antigens, and the immune response to them helps people fight infection. Some cancer cells carry antigens that lab tests can detect. Doctors use these to diagnose those cancers and to follow how treatment works. Other antigens on cancer cells take part in immune reactions that may help the body fight the cancer.

antimetabolites [an-tee-muh-TAB-o-lites or an-tie-muh-TAB-o-lites]: Substances that disrupt chemical processes in the body, for example the making of proteins, DNA (deoxyribonucleic acid) and other chemicals that a cell needs to grow and copy itself. As cancer drugs, they block DNA production. Then the cells cannot divide and the tumor cannot grow.

antioxidants [an-tee-OX-uh-dunts or an-tie-OX-uh-dunts]: Substances that protect cells from oxidation damage, which happens during metabolism. Vitamins C and E and beta-carotene are examples. Antioxidants in food are thought to lower the risk of some cancers. But in some people, some antioxidant supplements are linked with a higher cancer risk.

APC gene: A gene that helps cells grow at a balanced rate. If a person inherits a change in it, they can get familial adenomatous polyposis (FAP) or Gardner syndrome. A mutation (change) in this gene can cause hundreds of polyps to grow in the colon.

apheresis [a-fur-REE-sis]: A procedure that takes blood out of the body, removes one part of it and puts the rest back into the body. It is called plasmapheresis when plasma is removed, leukapheresis when white blood cells are removed and platelet pheresis when platelets are removed. Also called: pheresis (fur-REE-sis).

apoptosis [a-pop-TOE-sis]: Programmed cell death. Genes control it and make cells die at certain times, for example when their DNA is damaged. Cancer cells can block this process. Some cancer drugs cause apoptosis.

aromatase inhibitors: Drugs that block estrogen production by the adrenal glands. Doctors use them for hormone-sensitive breast cancer in women who have gone through menopause. Examples are anastrozole (Arimidex®), letrozole (Femara®) and exemestane (Aromasin®). Trials are checking whether they can also lower the risk of breast cancer in women after menopause.

aspiration [asp-er-A-shun]: To remove a liquid, a gas or pieces of tissue by suction. It can also mean to breathe food or liquid into the lungs by accident (aspirate).

asymptomatic [a-simp-tuh-MAT-ik]: Having no signs or symptoms of a disease.

ataxia-telangiectasia mutation (ATM) [a-tax-ee-yuh tel-an-jee-eck-TAY-zhuh]: An inherited change in a gene whose job is to repair damaged DNA. Ataxia-telangiectasia itself is a rare childhood disease that is inherited and slowly gets worse. It causes loss of muscle control and a weak immune system, and it raises cancer risk. People who carry the mutation can have a higher risk of several cancers.

attributable risk [at-trib-ut-a-ble risk]: How much a known factor adds to the risk of a disease, such as cancer. It is usually a percentage. It compares people who had the risk factor and got the disease with people who did not have the factor but got the same disease. For example, an attributable risk of 80% for a factor and a cancer means that 80% of people with this cancer had the factor and 20% did not.

atypia [a-tip-ee-yuh]: Not normal (atypical). The word often describes how cancer cells or precancer cells look.

atypical [a-tip-uh-kul]: Not usual; abnormal.

autologous [aw-tahl-uh-gus]: From the person's own body. It describes a procedure that uses the patient's own blood or tissue. For example, rebuilding a woman's breast with tissue taken from her own body is autologous tissue construction.

axillary dissection [ax-ill-air-ee di-sek-shun]: Surgery that removes the lymph nodes in the armpit (axillary nodes). These nodes are examined with a microscope for cancer.

B

barium sulfate [bear-ee-um sul-fate]: A chalky liquid that coats the digestive tract so it shows up on x-rays. You swallow it for an upper gastrointestinal (GI) series. For a lower GI series, it goes into the rectum as a barium enema. See also: gastrointestinal tract or GI tract.

basal cell carcinoma [bay-sul or bay-zul sell car-sin-O-ma]: Skin cancer of the most common type. It starts in the basal cells, which form the deepest layer of the epidermis (the skin's outer layer). It mostly appears on skin that gets sun, often the head and neck. It grows slowly and rarely spreads to distant parts of the body.

basic science: Science that gives the knowledge and background that later research on human health problems needs. In cancer research, it is often lab work in fields such as biochemistry, cell biology or genetics. This work does not aim to treat one specific cancer, but later it can be part of the basis for a treatment. Also called: pure science.

behavioral research: Research on why people act the way they do. Its results can help people choose healthy lifestyles and follow screening and treatment guidelines that save lives.

benign [be-nine]: Not cancer; not malignant.

beta carotene [bay-tuh KAIR-uh-teen]: A substance found mostly in yellow and orange fruits and vegetables. It acts as an antioxidant, and the body changes it into vitamin A.

Bethesda criteria [beth-ez-duh cry-teer-ree-yuh]: A checklist of traits that are common in people who have hereditary non-polyposis colon cancer (HNPCC). Fitting the checklist does not mean a person has HNPCC; most who fit it do not. Genetic testing for HNPCC is something they may want to consider.

bilateral [by-lat-er-ul]: Affecting both sides of the body. Cancer in both breasts, for example, is bilateral breast cancer. Compare to: unilateral.

biologic response modifiers [by-o-LA-jick re-spons MOD-uh-fie-urs]: Substances, such as the drug interferon, that make the immune system stronger against cancer. This treatment is sometimes called biologic therapy.

biomarkers [BY-o-mar-kers]: Substances, such as genes, proteins and hormones, that tests can look for to learn key facts about a cancer. They can help detect cancer, show whether treatment is working, or watch for a cancer that has returned (recurred). Also called: tumor markers.

biomarker testing [BY-o-mar-ker]: Tests for genes, proteins or other substances. They help find out whether:

• A cancer is more likely to grow and spread
• A certain treatment is likely or not likely to help
• Treatment is working
• A person may have a higher risk of some cancers
• A person may have a certain type of cancer (but a biopsy is usually needed to be sure)
• Cancer may be coming back

Also called: tumor testing, tumor genetic testing, tumor subtyping, genomic testing or genomic profiling.

biopsy [by-op-see]: Taking out a small piece of tissue, or some cells, to check them for cancer. Biopsies come in several types.

biopsy gun [by-op-see]: A tool that takes core biopsy samples. It is often used for prostate biopsies.

bisphosphonates [bis-FAHS-fun-ates]: Drugs that slow osteoclasts, the cells that break bone down. When cancer reaches the bones, it can make these cells overactive. The drugs can ease pain and lower high calcium levels caused by cancer in the bones. They can also slow that cancer's growth, delay or prevent fractures and, in some people, strengthen bones.

blood count: How many cells a measured sample of blood contains.

body image: A person's own view of their body, and how they believe other people see it.

bone marrow: The soft, spongy tissue in the hollow center of some bones. The body makes new blood cells here.

bone marrow aspiration and biopsy [asp-er-A-shun and by-op-see]: A procedure that puts a needle into the center of a bone, usually the hip bone or breast bone. The needle takes out a small amount of bone marrow, which is examined with a microscope.

bone marrow transplant: A treatment that gives healthy stem cells to replace the stem cells that high doses of chemotherapy, radiation therapy or both have destroyed. The marrow can come from the patient (autologous) or from a donor (allogeneic). Also called: stem cell transplant.

bone scan: An imaging test that gives important information about the bones, such as where cancer may have spread in them. A small amount of radioactive material (radioisotope) goes into a vein. It collects in areas of bone where cancer may be. These areas ("hot spots") show on the pictures.

bone survey: A set of x-rays that covers every bone in the body. It may be used to look for cancer that has spread to bone. Also called: skeletal survey.

brachytherapy [brake-ee-THER-uh-pee]: Radiation treatment from inside the body. The radiation source is usually sealed in a small holder called an implant, which is put very near the tumor or into it. Compare to: external beam radiation therapy.

brain scan: An imaging method that finds anything abnormal in the brain, such as brain cancer or cancer that has spread to the brain from another part of the body. It can be done in an outpatient clinic. The only pain is the needle stick when a radioactive substance (radioisotope) goes into a vein. The substance collects in abnormal areas, and these areas show on the pictures.

BRCA1: A gene that, when it is damaged (mutated), gives a person a higher risk of breast, ovarian, pancreatic, prostate and other cancers than people without the mutation.

BRCA2: A gene that, when it is damaged (mutated), gives a person a higher risk of breast, ovarian, pancreatic, prostate and other cancers than people without the mutation.

BRCAPRO: A tool that helps health professionals estimate a woman's breast cancer risk from certain risk factors.

breast specialist: A health care professional with a special interest in breast health. This person may have special knowledge, but medical licensing boards do not certify breast care as a specialty.

bronchoscopy [brong-kah-skuh-pee]: An exam of the bronchi in the lungs with a thin, flexible tube that has a light. The tube, called a bronchoscope, goes down the throat.

C

CA 19-9: A tumor marker that colorectal, stomach, bile duct and pancreatic cancers sometimes make. Conditions that are not cancer can also make it.

cachexia [ka-kek-see-uh]: A large loss of weight and muscle caused by loss of appetite and poor nutrition.

calcifications [kals-if-ik-A-shuns]: Very small deposits of calcium in the breast, alone or in groups. Mammograms often show them. The smallest ones may be called microcalcifications. They show changes in the breast that may need more mammograms or a biopsy.

cancer: A group of diseases in which body cells change and start to grow without control. Most cancers make a lump or mass, called a tumor. A tumor can be benign, which means it is not cancer, or malignant, which means it is cancer. A malignant tumor can grow into healthy tissue and destroy it.

cancer care team: All the health care professionals who find, treat and look after a person with cancer. They may work together formally or informally. Usually one of them coordinates the team.

cancer cell: A cell that divides and multiplies in an abnormal way. It can spread through the body and push out normal cells and tissue. Cancer cells form because of many changes in certain genes.

cancer-related fatigue: Unusual tiredness that continues and that can come with cancer or its treatment. It can be very strong, last a long time and get in the way of daily life. Rest does not always make it better.

cancer screening tests: See: screening.

cancer surveillance: The continuous, timely and organized collection and study of public health information about new cancer cases, how far the disease has spread, screening tests, treatment, survival and cancer deaths.

cancer susceptibility genes: Genes that, with certain mutations, can raise a person's risk of some cancers. These genes usually come from one or both parents.

cancer vaccine: A vaccine that trains a person's immune system to attack cancer cells. It can help treat a cancer, or help keep it from returning after other treatment. A few vaccines, such as the HPV vaccine, may instead help prevent some cancers.

cannula: A narrow tube. Different types can hold tissues open during laparoscopy or give IV medicines and fluids.

capsular contracture: Hardness and change of shape in an area, caused by scar tissue that forms around an implant in the body.

capsule formation: Scar tissue that can form around an implant because the body reacts to a foreign object.

carcinoembryonic antigen (CEA) [car-sin-o-em-bre-ON-ic an-tuh-jin]: A substance that is normally in some tissues of an unborn baby. In an adult, it can be a sign of cancer, mostly cancer that starts in the digestive system. Tests for it can help doctors find out whether colorectal cancer has come back after treatment.

carcinogen [car-sin-o-jin]: Any substance that causes cancer or helps it grow.

carcinoid syndrome [car-sin-oyd sin-drom]: A group of symptoms caused by carcinoid tumors that release large amounts of hormones. The symptoms include a flushed face, wheezing, diarrhea, a fast heartbeat and others.

carcinoid tumor [car-sin-oyd]: A tumor that grows from neuroendocrine (nerve and endocrine) cells. It can release hormones that cause symptoms such as a flushed face, wheezing, diarrhea and a fast heartbeat.

carcinoma [car-sin-O-ma]: Cancer that starts in the skin or in the layer of cells that lines organs (epithelial cells).

carcinoma in situ [car-sin-O-ma in sy-too]: An early cancer that has stayed in the organ where it started. It has not grown into other parts of that organ, and it has not spread to distant parts of the body. Most can be cured.

cardiologist: A doctor who specializes in the heart and blood vessels. People with cancer may see one for heart disease or for heart problems caused by treatment.

case manager: The cancer care team member who organizes the patient's care from diagnosis through treatment and recovery. This person often deals with the insurance company and links the patient and family to helpful resources.

castration [cass-tray-shun]: Surgery, radiation or medicine that stops the ovaries or testicles from making hormones.

catheter [cath-it-ur]: A thin, flexible tube that lets fluids go into or out of the body. For example, a Foley catheter drains urine, and an IV catheter gives fluids or medicines into a vein.

causal association or causal link [kaw-zul]: A link in which one factor is believed to bring about a result. For example, smoking is believed to cause lung cancer, so the two have a causal link.

CDH1: A gene. An inherited mutation in it can cause hereditary diffuse gastric cancer, a rare stomach cancer, to start at a young age. In women, changes in this gene also raise the risk of lobular breast cancer.

cell: The basic building block of all living things. Cells replace themselves when they split to make new cells (mitosis). In cancer, the processes that control how new cells form and old cells die do not work correctly.

cell cycle: The steps a cell goes through before it divides. Some chemotherapy drugs work by blocking a step in this cycle.

centimeter [SIN-tuh-me-ter]: A metric unit of length, written cm, equal to 1/100 of a meter. About 2½ cm equal 1 inch. See also: millimeter.

cerebrospinal fluid [suh-REE-bro-spy-nuhl]: A clear liquid around the brain and spinal cord that cushions them. Also called: CSF.

cGy: See: Gray, under radiation dose.

chaplain: A member of the clergy who helps with the spiritual needs of the patient and family. A chaplain can usually help people of many faiths, denominations and beliefs.

CHEK2: A gene that, when it is damaged or mutated, can raise the risk of breast cancer and other cancers. A person can inherit a damaged CHEK2 gene.

chemo brain [key-mo brain]: A change in thinking. A person may feel less mentally "sharp," forget some things, or have difficulty finishing tasks, concentrating or learning new skills. It can occur at any time with cancer, before or after treatment.

chemoprevention [key-mo-pre-VEN-shun]: Using drugs, chemicals or other substances to try to prevent cancer, or to lower the chance that cancer comes back.

chemotherapy [key-mo-THER-uh-pee]: Medicines that treat cancer. You can get them alone or together with surgery, radiation therapy, hormone therapy, targeted therapy or immunotherapy. They can go into a vein as an infusion, be given as a shot or be swallowed. Often called: chemo.

chromosome [KROM-uh-som]: A long strand of DNA that holds genes, the basic units of heredity. Each chromosome can hold hundreds or thousands of genes. Most human cells have 23 pairs. In each pair, one comes from the mother and one from the father.

chronic inflammatory bowel disease: See: inflammatory bowel disease (IBD).

chronic obstructive pulmonary disease (COPD) [kron-ick ob-struck-tiv PULL-muh-nerr-ee]: Lung disease, such as emphysema or chronic bronchitis, that damages the lungs and makes breathing harder. It is more common in people who smoke.

chyme [kime]: The thick, almost liquid mix of partly digested food and digestive juices in the stomach and small intestine.

cirrhosis [seh-ROH-sis]: A disease in which liver cells are damaged and scar tissue takes their place. People with cirrhosis have a higher risk of liver cancer.

Claus model: A tool that helps health professionals estimate a woman's breast cancer risk from certain risk factors.

clinical breast examination (CBE): A doctor, nurse or other health professional checks the breasts for lumps or other changes. Often shortened to: CBE.

clinical nurse specialist (CNS): An advanced practice registered nurse (APN or APRN) who holds a master's or doctoral degree and a special certification. A CNS is trained and experienced in one area of medicine and nursing, and works closely with everyone on the care team. In oncology, a CNS may care for patients and families, supervise staff, research nursing care for people with cancer, or teach about cancer, its treatment and side effects.

clinical stage: See: stage.

clinical trials: Studies in which people volunteer to help test new drugs or other treatments. They compare standard treatments with ones that may work better. Some test new ways to diagnose or prevent a disease.

clinical trials nurse: A nurse who supports patients in a clinical trial. This nurse teaches the patients, watches their condition and manages their care during the study.

colectomy [kuh-lek-tuh-me]: Surgery that removes all of the colon (total colectomy) or part of it (partial colectomy or hemicolectomy). See also: segmental resection, anastomosis.

colitis [kuh-lie-tis]: Inflammation of the colon (large intestine). It is a general word. The inflammation may come and go, or it may be chronic and last a long time, as ulcerative colitis does. See also: inflammatory bowel disease (IBD).

colonoscopy [ko-lun-AH-skuh-pee]: A procedure that lets a doctor look inside the large intestine, including the colon, for polyps or cancer.

colony-stimulating factors (CSF): Substances that make the bone marrow produce more blood cells. The body makes them naturally. Doctors may give them to reduce or prevent some side effects of chemotherapy caused by too few blood cells. They can also be given to a donor before stem cells are collected for a peripheral blood stem cell transplant.

color Doppler ultrasound: A type of ultrasound in which a computer changes sounds into colors that show blood flow in an organ. It makes it easier for doctors to see whether cancer has spread into blood vessels.

combination hormone therapy: See: combined androgen blockade.

combined androgen blockade (CAB): Treatments that lower or stop the production of androgens (male hormones). For example, prostate cancer can be treated by fully blocking androgen production, which can include removal of the testicles plus anti-androgen drugs.

combined modality therapy [mo-dal-ih-tee]: Using more than one type of treatment, together or in turns, to get the best result. A common example is chemotherapy after cancer surgery, to kill cancer cells that may have spread beyond where the tumor started.

comedocarcinoma [kom-id-o-car-sin-NO-muh]: Ductal carcinoma in situ with dead or dying cancer cells in its center.

complementary therapy: A method outside standard care that a person uses together with standard medical treatment. It does not treat the cancer itself. It can ease symptoms and side effects, and it may help well-being and quality of life. Some examples: meditation, acupuncture, yoga, massage, reflexology, guided imagery and physical activity. Compare to: alternative medicine.

complexed PSA: PSA (prostate-specific antigen) that circulates attached to other blood proteins. It is the PSA that is not "free." One complexed PSA test is done in place of two tests, total PSA and free PSA, and it may give as much information as both. Researchers are studying whether it is as accurate. Related terms: PSA, percent-free PSA.

concurrent treatment: A treatment or therapy given at the same time as another treatment.

conditioning treatment: Treatment given before a stem cell transplant to destroy the bone marrow or weaken it. It helps kill any cancer cells, gives the new stem cells room to grow and makes it less likely that the body rejects them.

conformal proton beam therapy: See: proton beam therapy.

conformal radiation therapy: Radiation treatment in which a special computer helps shape the radiation beams to the shape of the tumor. The beams come from several directions, not from one angle. Because the entry points are spread out, each area of healthy tissue gets less radiation.

control group: The people in a study or clinical trial who do not get the treatment under test. In cancer research, they usually get the standard treatment, which is already tested and widely used. When no standard treatment exists, they may get a placebo or sham treatment. Most cancer trials give a placebo only together with an active drug, because giving a placebo in place of a treatment known to work is unethical. Also called: comparison group.

conventional therapy or treatment: See: standard therapy.

cord blood transplant: Use of stem cells from the blood of newborns' placentas and umbilical cords. These cells replace a patient's blood-forming stem cells that radiation or chemotherapy has destroyed.

core needle biopsy: A procedure that takes tissue samples with a wide needle that removes a small cylinder of tissue. A pathologist examines the samples with a microscope to find out if cancer cells are present.

corticosteroid [kor-tih-ko-STEER-oyd]: A steroid substance from the cortex, the outer layer of the adrenal glands. There are several. Doctors sometimes use them to treat cancer or to lower nausea, and to ease pain from cancer in the bone.

cranium [cray-nee-um]: The skull bones of the head. The cranium surrounds and protects the brain and holds up the structures of the face.

Crohn’s disease or Crohn’s colitis [kronz]: A long-lasting inflammatory bowel disease. The inflammation is mostly in the small bowel, and less often in the colon, and it lasts a long time. People who have it have a higher risk of colon cancer.

cryoablation [cry-o-ah-BLAY-shun]: Killing cancer cells by freezing them with extreme cold. Also called: cryosurgery, cryotherapy.

cryosurgery [cry-o-SUR-juh-ree]: See: cryoablation.

cryotherapy [KRY-oh-THAYR-uh-pee]: See: cryoablation.

CT colonography: See: virtual colonoscopy.

CT-guided needle biopsy: A biopsy in which the doctor uses CT images to steer the needle toward a suspicious area or mass. More images are taken until the doctor is sure the needle is inside the tumor or mass. Then a sample is taken out for study with a microscope.

CT scan, CAT scan, or computed tomography scan [toe-mahg-ruh-fee]: An imaging test made of many x-rays taken from different angles. A computer joins them into 3-dimensional (3-D) pictures of organs and tissues. Doctors use CT scans to find cancers, see a tumor's size and shape, and check how well treatment is working.

cumulative [kyoo-myuh-luh-tiv]: Building up over time as more is added, in amount, strength or effect. Cancer treatment side effects, for example, can build up and get worse with each cycle or each new treatment course.

curative treatment [kur-uh-tiv]: Treatment meant to get rid of all the cancer. After it, no more treatment should be needed and the cancer should not return.

cyst [sist]: A pocket of tissue that can hold fluid, air or pus. Cysts can form anywhere in the body, and they are usually not cancer.

cystoscopy [sis-tah-skuh-pee]: A procedure that looks inside the urethra and bladder with a thin, flexible tube that has a light. The tube is called a cystoscope.

cytogenetics [sy-toe-juh-NET-icks]: Lab tests that check chromosomes for abnormal changes (mutations). They use samples of blood, bone marrow or tissue. Changes in certain chromosomes can point to some cancers or genetic diseases.

cytokine [sy-toe-kine]: A substance made by immune system cells that can change how the immune system responds. Labs can also make cytokines, which are given to people to strengthen the body's immune response to cancer. See also: immune system.

cytology [sy-tahl-uh-jee]: The study of cells with a microscope. The word also means tests that diagnose cancer and other diseases by looking at cells with a microscope.

D

debulk [de-bulk]: To use surgery to make the amount of cancer smaller. The surgeon usually takes out as much as can be removed safely. This can make it more likely that other treatments, such as chemotherapy or radiation therapy, kill all the tumor cells. Debulking can also be done to ease symptoms.

depot injection [dee-poe or dep-oh]: A way to inject a drug so that it goes into the blood slowly over a long time. Drugs given this way can often be given once a month, or even once every few months.

dermatologist or dermatological oncologist [der-muh-TAHL-uh-jist]: A dermatologist is a doctor who treats diseases of the skin. A dermatological oncologist has extra training to find and treat skin cancers.

detection: See: early detection.

diabetes [dai-uh-bee-teez]: A condition that changes how the body makes energy from food. In diabetes, the body does not make enough insulin, or it does not use insulin correctly. As a result, too much sugar stays in the blood.

diagnosis [die-ug-NO-sis]: Finding out which disease or condition a person has. Doctors use the signs and symptoms, and also imaging tests, lab tests or a biopsy.

diaphragm [DIE-uh-fram]: A muscle shaped like a dome. It is between the chest and the abdomen (belly). When it moves down, air comes into the lungs. When it moves up, air goes out.

dietary supplement: A product that a person adds to their diet to try to improve their health, for example a vitamin, a mineral or an herb. It is not meant to diagnose, treat, cure or prevent disease. The law does not treat supplements as drugs. Because of this, companies can sell them without proof that they are safe or that they work.

diethylstilbestrol or DES [die-ETH-ul-still-bes-trahl]: A man-made estrogen. From 1938 to 1971, doctors gave it to some pregnant women to help prevent miscarriage or early birth. A person who was exposed to DES before birth (as an embryo or fetus, when the mother took it) can have a higher risk of some cancers. Women who took DES while pregnant can have a slightly higher risk of breast cancer. DES is not available in the United States now. Also called: DES.

dietitian or registered dietitian [die-uh-TISH-un]: A registered dietitian (RD) has passed a national board exam and is an expert in food, diet and nutrition. Many RDs focus on one area. Examples are cancer care, cardiac rehabilitation, exercise science and weight management. See also: nutritionist.

differentiation [dif-uhr-en-she-A-shun]: How mature a cell is, and so how well it can do its correct job. For cancer, it tells how closely the cancer cells look like the normal tissue where they started. Cells that are well differentiated look more like normal cells. They usually grow and spread at a slower rate than cells that are poorly differentiated or undifferentiated.

digital mammography: A breast x-ray that is kept as a computer image, not on standard x-ray film. Also called: 3D mammogram.

digital rectal exam (DRE): An exam in which the doctor puts a gloved, lubricated finger into the rectum to feel for anything abnormal. This simple test usually does not hurt. It can find some prostate cancers and rectal cancers. Also called: DRE.

dihydrotestosterone or DHT [die-hi-dro-tes-TOSS-ter-own]: A male hormone that the body makes from testosterone. High levels of DHT can make prostate cancer grow more and can make it more difficult to treat. Also called: DHT.

dilation and curettage or D & C [die-lay-shun and cure-uh-TAZH]: A procedure in two steps. First, the cervix is opened a little (dilation). Then tissue is taken from the lining of the womb (uterus) (curettage). Doctors often use it to get tissue for a biopsy. Sometimes they take out everything inside the uterus. Also called: D & C.

dimpling: A pucker or a small dent in the skin. Dimpling of the breast can be a sign of cancer.

discharge: Fluid that leaves a part of the body.

discharge coordinator or planner: A person, often a nurse or a social worker, who makes sure that patients who leave the hospital have what they need to continue to recover at home. This person can also help a patient find another place to go after the hospital, such as a nursing home or a rehab center, where the patient can continue to get the necessary care.

disease-free survival rate: The percentage of people with a specified cancer who are alive and have no sign of cancer at a set time after treatment. This time is usually 5 years.

dissection [di-sek-shun]: Surgery that divides, separates or removes tissues.

distal: Farther from the torso than another part of the body. The word is usually used for a limb. For example, the knee is distal to the hip, and the ankle is distal to the knee.

distant cancer: Cancer that has spread far from where it started (the primary site) to organs or lymph nodes far away. It is sometimes called distant metastases.

diverticulitis [die-ver-tick-you-LIE-tis]: Small pouches can form where the colon wall is weak. Diverticulitis is when these pouches become infected or inflamed. It can cause cramps in the muscles, mild pain or a small amount of bleeding.

diverticulosis [die-ver-tick-you-LOW-sis]: Small sacs or pouches in the wall of the colon. If these pouches become inflamed or infected, the result is diverticulitis.

DNA or deoxyribonucleic acid [dee-ok-see-ri-bo-noo-KLEE-ick]: The genetic "blueprint" in the nucleus (center) of a cell. DNA contains the genetic instructions for how a cell grows, divides and works. Parents pass DNA to their children.

DNA repair: The process that fixes the genetic mistakes that occur each time a cell divides. If this repair does not work correctly, the risk of some cancers can increase.

doctor of osteopathic medicine or DO: A doctor whose license and education are very similar to those of a medical doctor (MD). A DO has special training to treat the "whole person", not only specific symptoms. See also: primary care physician or provider.

dominant allele: See: allele.

dorsal: About the back side of the body or of a body part.

dose-dense chemotherapy: Chemo given at the usual doses, but with less time between treatments than in a standard plan. For some types of cancer, this can decrease the chance that the cancer comes back. It can cause more side effects and can be more difficult to tolerate, so it is not a choice for everyone.

dosimetrist [doe-sim-uh-trist]: A trained, certified specialist who works out the correct radiation dose for the treatment of cancer and other diseases. The plan sets how much radiation is given, how fast, and how it is spread out.

doubling time: The time that a cell needs to divide, or that a group of cells needs to double in size. This time is different for different cancer cells. A cancer can be in the body for many years before it can be found.

drug resistance: When the drugs that are meant to destroy cancer cells or other microorganisms do not affect them.

durable power of attorney for health care: A legal document in which you choose a person to make all your health care decisions if, in the future, you cannot make them yourself. It is a type of advance directive.

dysphagia [dis-fay-zhe-uh]: Difficulty swallowing.

dysplasia [dis-play-zhuh]: Abnormal changes in groups of cells in a tissue or an organ. Dysplasia is not cancer, but sometimes these changes can become cancer.

E

early detection: Finding a disease at an early stage, before it is large or has spread, when it is easier to treat. Some tests are done before a person has symptoms to try to find cancer early.

edema [uh-DEE-muh]: Swelling caused by fluid that collects in the tissues.

efficacy [EF-ih-kuh-see]: How well a treatment works. It is the ability of a treatment to give the result that is wanted.

ejaculate [ih-JACK-you-late]: To release semen during male orgasm.

electrocoagulation or electrofulguration [e-lek-tro-ko-ag-yuh-LAY-shun or e-lek-tro-ful-ger-AY-shun]: A treatment that uses an electrical current to burn and destroy cancer cells. Also called: electrocautery.

embolization [em-buh-li-ZAY-shun]: A treatment that stops or decreases the blood supply to a cancer. Materials are injected to block the artery that brings blood to the tumor.

emesis [em-eh-sis]: Vomit, or the act of vomiting.

endocavitary radiation therapy [end-oh-KAV-uh-ter-ee]: Radiation therapy for cancer that is given from a handheld device put inside an opening of the body. It can be given alone or together with external beam radiation therapy.

endocrine glands [en-duh-krin]: Organs that put hormones into the blood. Examples are the ovaries, the testicles, the thyroid and the adrenal glands.

endocrine therapy [en-duh-krin]: Treatment of a disease or condition by changing hormones.

endocrinologist [en-duh-kruh-NAHL-uh-jist]: A doctor for diseases of the endocrine glands. These include the adrenal, pineal, pituitary and thyroid glands, and the pancreas.

endoscopy [en-dahs-kuh-pee]: A look at the inner lining of hollow organs or spaces in the body. The doctor uses a thin, flexible tube with a light, called an endoscope.

enterostomal therapist [en-ter-oh-STO-mal ther-uh-pist]: A trained and certified nurse who teaches people how to care for wounds and for ostomies (openings made by surgery, such as a colostomy or a urostomy). Also called: ostomy nurse or wound care nurse.

enterostomal therapy nurse: A nurse who shows people how to look after their wounds, or the openings that surgery makes (for example ostomies). Also called: ostomy nurse or wound care nurse.

enucleation [ee-noo-klee-AY-shun]: Surgery that removes something without cutting into it. The word can mean the removal of a whole tumor. It can also mean the removal of a whole eyeball, while the eye muscles and other contents of the eye socket stay.

enzyme [en-zime]: A protein that starts, helps or speeds up chemical reactions in living cells.

epidemiology [ep-ih-deem-ee-AHL-uh-jee]: The study of diseases in populations. A population is a large group of people who share a factor such as age, sex or a health condition. Epidemiologists collect and analyze statistics. In cancer, they study how many people have cancer, who gets specific types of cancer, and which factors are linked to cancer. Examples of these factors are the environment, hazards at work, family patterns and personal habits such as smoking and diet.

epidermal growth factor (EGFR) [ep-ih-DERM-uhl]: Proteins on the surface of cells that tell the cells to grow and divide. Some cancer cells have more of these growth factor receptors than normal cells, so they grow faster. Drugs that block EGFR signals (EGFR inhibitors) can treat some types of cancer.

epidural anesthesia [ep-ih-DUR-uhl an-es-THEE-zhuh]: Numbing drugs injected into the space around the spinal cord. They make the lower part of the body numb.

erectile dysfunction: A man is not able to get an erection of the penis, or not able to keep one. Also called: ED or impotence.

esophageal speech [eh-sof-uh-JEE-uhl]: A way to talk without a voice box (larynx), after surgery has removed it. With practice, a person can learn to swallow air into the esophagus (the tube between the mouth and the stomach) and push it back out of the mouth. The moving air makes the throat vibrate, and training turns these vibrations into speech. It is the simplest kind of speech rehabilitation. Often, newer devices and surgery methods mean that a person does not need to learn it.

estrogen: A hormone that both men and women have, but women have more of it. People often call it the female sex hormone. The ovaries make most of it, and the adrenal cortex makes small amounts. In girls, estrogen helps control puberty, for example breast growth. In women, estrogen levels usually go up and down each month. This controls menstruation and prepares the body for fertilization and reproduction. Estrogen can help cancer cells grow in breast, endometrial and adrenal cancers. In men, doctors sometimes use estrogen to treat advanced prostate cancer, because it works against testosterone.

estrogen receptor assay: A lab test that checks a sample of the cancer for estrogen receptors. Estrogen causes normal breast cells, and some breast cancers, to grow. Cancers with these receptors (estrogen receptor-positive) are more likely to respond to hormone therapy. Cancers without them (estrogen receptor-negative, or ER-negative) probably will not respond to it.

estrogen therapy: See: hormone replacement therapy (HRT).

etiology [ee-tee-AHL-uh-jee]: What causes a disease. Cancer can have many causes. Research shows that, in many cancers, two major factors are lifestyle (including contact with carcinogens) and genetics (the genes you get from your parents).

excision [ex-sih-zhun]: Surgery that cuts something out or off. It can mean removing a tumor or removing a part of the body.

excisional biopsy [ex-sih-zhun]: Surgery through the skin that removes a whole tumor. The lab then examines the tumor for cancer.

explanation of benefits: A document from a health insurance company. It tells which parts of a medical or health claim the company paid, and which parts it did not pay.

external beam radiation therapy: Radiation that comes from a source outside the body and is aimed at the cancer. It is similar to an x-ray, but it lasts longer. Also called: EBRT. Compare to: brachytherapy.

F

false negative: A test result that shows that a condition is not present, but it is present.

false positive: A test result that shows that a condition is present, but it is not present.

familial adenomatous polyposis (FAP) [fa-mil-e-uhl ad-no-muh-tus or ad-uh-NO-muh-tus pa-lih-PO-sis]: A condition that runs in families. It causes many polyps on the inner wall of the rectum and colon. (A polyp is an abnormal growth on the inside lining of an organ.) People with FAP are more likely to get colorectal cancer when they are young. FAP can also raise the risk of cancer in the bile duct, brain, pancreas, thyroid, adrenal gland, liver, small intestine and stomach.

fascia [fash-uh]: Fibrous tissue in a sheet or a thin band. It covers the muscles and some organs.

fatigue [fuh-teeg]: A very strong feeling of tiredness or lack of energy. People often say that they feel exhausted. It can continue even when a person seems to get enough sleep or rest. The fatigue that often occurs with cancer is called cancer-related fatigue.

fat necrosis [nuh-crow-sis]: Death of fat cells, usually after an injury. It is not cancer, but it can cause lumps and can pull on the tissues. In the breast, it can look like breast cancer.

fecal immunochemical test [fee-kuhl im-you-no-KIM-uh-kuhl test]: A test that looks for hidden blood in the stool. Hidden blood can be a sign of colorectal cancer. The test uses an antibody that attaches to hemoglobin to find blood. Also called: FIT.

fecal occult blood test (FOBT): A test that looks for hidden blood in the stool. Hidden blood can be a sign of colorectal cancer.

feces [fee-sees]: Solid waste from the body; stool.

fiber, dietary: The part of plant carbohydrates that the body cannot digest. These carbohydrates come from fruits, vegetables, whole grains and legumes. Beans, vegetables, whole grains and fruits are good sources of fiber. Research has not proved a link between fiber alone and cancer risk. But experts still recommend these foods, because they contain other substances that can help prevent cancer, and they are good for health in other ways.

fibrocystic changes [fie-bro-SIS-tick]: Changes in the breast that are not cancer. Symptoms can include lumps, swelling, and tenderness or pain in the breast. Symptoms are usually worse just before the menstrual period, and they can change during the menstrual cycle.

fibrosis [fie-bro-sis]: Scar-like (fibrous) tissue that forms in any part of the body.

fine needle aspiration biopsy (FNA or FNAB) [asp-er-A-shun by-op-see]: A procedure that uses a thin needle to pull out (aspirate) samples. The samples are then examined with a microscope.

first-degree relative: A parent, a sibling (brother or sister) or a child who is related to you by blood.

fistula [fist-chu-luh]: A connection, opening or passage that should not be there. It can join two organs inside the body, or join an organ to the outside of the body. It can come from injury or inflammation, or surgery can make it.

five-year (5-year) relative survival rate: This rate compares two groups. One group is people whose cancer was found 5 years ago and who are still alive. The other group is people of the same age without cancer. For example, if a stage of breast cancer has a 5-year relative survival rate of 90%, women with it are, on average, about 90% as likely as women without it to live 5 years or more after diagnosis.

five-year (5-year) survival rate: Of all the people with one type and stage of cancer, the percentage still alive at least 5 years after diagnosis. It does not tell one person how long they will live. It can help a person see how likely it is that treatment will succeed.

flow cytometry [sy-tahm-uh-tree]: A test of cells from a biopsy, a cytology sample or a blood sample. It uses special antibodies and a laser beam. It is often used to find the exact type of leukemia or lymphoma that a person has. It can also measure how much DNA is in cancer cells.

fluorescent in situ hybridization or FISH [floo-res-uhnt in sy-too hi-brid-ih-ZAY-shun]: A test that looks at the chromosomes in cells and tissues. Special fluorescent dyes attach only to some parts of the chromosomes, so the test can find specific DNA (deoxyribonucleic acid) sequences. It can help to make a diagnosis, to estimate the outlook (prognosis), or to check if a disease is in remission. Also called: FISH.

follicle [fah-lick-uhl]: A structure shaped like a sac or a pouch. The body has many types and sizes of follicles. For example, in the scalp one follicle holds one hair, and in the ovary one follicle holds one egg.

follicular [fah-lick-yuh-ler]: About one or more follicles. In medicine, it can name a type of cell in an organ. It can also name a cancer that starts in follicular cells.

fracture [frack-chur]: A partial or full break, usually in a bone.

frozen section: A very thin slice of tissue that is frozen fast, so that the pathologist can look at it with a microscope during the surgery. Surgeons sometimes use it when they need facts about the tissue to make a decision immediately. A few days later, a more detailed study (a permanent section) confirms the diagnosis.

full body CT scan: A scan of the body from the chin to below the hips, done to look for early signs of disease in people without symptoms. No benefit of this test has been proven. It can cause harm, because the person gets quite a high dose of radiation.

G

Gardner syndrome: An inherited condition in which polyps (abnormal growths) grow on the inner lining of the colon and rectum. People with Gardner syndrome have a higher risk of colorectal cancer at a young age. It can also cause benign (not cancer) tumors of the skin, the soft connective tissue and the bones. It can also increase the risk of other types of cancer.

gastric [gas-trick]: About the stomach.

gastroenterologist [gas-tro-en-ter-AHL-uh-jist]: A doctor who treats diseases of the digestive tract (the gastrointestinal or GI tract).

gastrointestinal tract or GI tract [gas-tro-in-TEST-uh-nul trakt]: The organs and structures that turn food into a form that the body can use for energy, and that get rid of solid waste. They are the mouth, throat, esophagus, stomach, small and large intestines, rectum and anus. Also called: GI tract or digestive tract.

gene: A section of DNA that children get from their parents. Genes carry the information for traits that are inherited, such as height, eye color and hair color. They also affect the chance that a person gets some diseases.

gene therapy: An experimental treatment that replaces defective genes with normal or changed genes, or adds new genes. The goal is to prevent or treat some diseases, such as cancer.

genetic [juh-neh-tick]: About genes.

genetic counseling: Talks with people who could have a gene that makes them more likely to get a disease. A health professional with special training usually does it. Counseling looks at the genetic risk and at whether genetic tests are necessary. It explains what the test results could mean, helps the person decide if they want the test, and gives support before and after the test.

genetic counselor: A health professional with special training who helps people understand their risk of a genetic disorder. The counselor uses personal and family history to decide if genetic testing can help. The counselor also meets people after genetic testing and gives information about screening choices and ways to prevent disease, based on the results.

genetic testing: Tests that look for gene changes that are known to make cancer more likely. Not everyone should have these tests. They are recommended for people with some kinds of family history. The testing process should include genetic counseling.

genome [jee-nome]: All the genetic material in a cell or an organism. It includes all the DNA, and sometimes ribonucleic acid (RNA). It gives all the information that a person needs to function.

genomics [jee-nome-ics]: The study of the genome (a person's genetic material, including DNA and RNA) and of how it works.

genomic testing: Tests of all of a person's genes. They help show how a cancer will grow and which treatment is likely to work best. If possible, the test is done on tumor tissue from a biopsy or surgery. Blood, saliva or another body fluid can also be used.

germ cell: The reproductive cells of the body: eggs (ova) in females and sperm cells in males.

glands: A cell or a group of cells that makes and releases substances. The body uses these substances or sends them out of the body. Sweat glands are an example.

glandular tissue [glan-juh-luhr tish-oo]: Tissue that makes and releases substances such as breast milk, semen, sweat and saliva. Many organs have glandular tissue, including the colon, stomach, pancreas, lungs and cervix.

Gleason grade: A number from 1 to 5 that tells how much prostate cancer cells look like normal prostate cells. Cells that look very much like normal cells get grade 1. Cells that look the least like normal cells get grade 5.

grade: A number that tells how much cancer cells look like normal cells. A low grade usually means that the cells look more like normal cells, grow more slowly and are less likely to spread. A high grade means that the cells look less like normal cells, grow faster and are more likely to spread.

graft-versus-host disease (GVHD): A condition in which immune cells from a donor attack the tissues of the person who receives the transplant. The transplant is usually a bone marrow or other stem cell transplant.

gray (Gy): A unit used to measure radiation. See also: radiation dose.

growth factors: Proteins that occur naturally and make cells grow and divide. Some cancer cells make too much growth factor, and this helps them grow quickly. Clinical trials are testing new treatments that block these growth factors. Doctors sometimes use other growth factors to help normal cells recover from the side effects of chemotherapy.

guaiac [gwi-ack]: A substance used in the fecal occult blood test to look for blood in a person's stool.

gynecologic oncologist [guy-nuh-kuh-LA-jik on-kahl-uh-jist]: A doctor who treats cancers of the female sex (reproductive) organs.

gynecologist [guy-nuh-KAHL-uh-jist]: A doctor who treats female health problems, including sexual and reproductive function and diseases of the reproductive organs. This does not include breast diseases that need surgery.

gynecomastia [guy-nuh-ko-MAST-tee-uh]: Male breast enlargement: a male has more breast tissue than usual. It can feel like a lump shaped like a button or a disk below the nipple and the areola (the dark circle around the nipple), and sometimes it can be seen. It can also look like small breasts. Causes include some medicines and hormone changes or imbalances.

H

health care power of attorney: See: durable power of attorney for health care.

health disparity: A difference in health that can be prevented and that has a close link to disadvantage of a social, political, economic or environmental kind. It can be related to race, ethnicity, sex, gender identity, sexual orientation, age, religion, disability, education, income, place of residence or other characteristics. For example, people in some racial and ethnic groups have more problems getting good health care, healthy food or the newest medical treatments. As a result, these groups can have more disease, disability and death than other groups. Research continues on health disparities in specific groups and on how to reduce them.

hematochezia [he-muh-toe-KEEZ-ee-uh or hem-at-uh-KEEZ-ee-uh]: Bright red blood in the stool.

hematocrit [he-mat-uh-krit]: The percentage of the blood that is red blood cells. A hematocrit test can help find conditions such as anemia.

hematologist [he-muh-TAHL-uh-jist]: A doctor for blood disorders (blood dyscrasias). This includes cancers of the blood and of the tissues that make blood.

hematologist-oncologist [he-muh-TAHL-uh-jist on-kahl-uh-jist]: A medical doctor who has trained in cancer care and also in diseases of the blood. See also: hematologist, oncologist.

hematoma [he-muh-TOE-muh]: Blood that collects outside a blood vessel because of a leak or an injury. A bruise is one example.

hematuria [he-muh-TUR-ee-uh]: Blood in the urine.

hemoglobin [HE-muh-glo-bin]: The part of a red blood cell that carries oxygen. In people with cancer, hemoglobin levels can become very low, especially during some treatments.

hemorrhoids [hem-uh-royds]: Swollen, painful veins in the anus. They can bleed.

hepatitis [hep-ah-tie-tis]: Swelling (inflammation) of the liver.

hepatologist [hep-a-TAH-loh-jist]: A doctor who treats diseases of the liver and the bile ducts.

hepatomegaly [hep-at-o-MEG-uh-lee]: A liver that is larger than normal.

HER-2 or human epidermal growth factor receptor 2: A protein that some cancers have in large amounts (HER-2 positive). HER-2 positive cancers usually grow faster and spread more than HER-2 negative cancers. Also called: HER2 or HER2/neu.

hereditary cancer syndrome: A condition in which gene changes that a person inherits give them a higher than normal risk of some types of cancer.

hereditary non-polyposis colon cancer (HNPCC) [huh-RED-ih-ter-ee non-pah-lih-PO-sis]: A condition that runs in families and makes colorectal cancer much more likely. It also raises the risk of other cancers: of the lining of the uterus (endometrial cancer), of the ovary, stomach and small bowel, and of the lining of the ureters or the kidney. People with this condition often get cancer at a young age, without first getting many polyps. Also called: Lynch syndrome.

hesitancy: Difficulty starting to urinate, or difficulty continuing to urinate after it starts.

heterogeneous [HEH-teh-roh-JEE-nee-us]: Made of different parts or elements, for example cells or tissues that do not look the same.

high-dose rate (HDR) or temporary brachytherapy [brake-ee-THER-uh-pee]: A radiation treatment that puts a radioactive source in or near a cancer for a short time and then removes it. Also called: HDR brachytherapy.

high risk: When the chance of getting a disease, such as cancer, is much higher than it usually is in the general population.

histology [hiss-tah-luh-jee]: The study of cells or tissues with a microscope.

home health nurse: A nurse who gives care in the patient's home. This includes giving medicines and some treatments, teaching about them, and checking if the patient needs other medical care.

homogeneous [home-uh-JEE-ne-us]: Cells or tissue that look the same in all areas.

homologous recombination [home-uh-la-gus re-com-bin-a-shun]: An exchange of genetic material that repairs damaged DNA. Also called: HR.

homologous recombination deficiency [home-uh-la-gus re-com-bin-a-shun de-fi-shen-se]: A condition in which cells cannot exchange some parts of their genetic material to repair damaged DNA. A test called an HRD biomarker can show if this deficiency is present. If it is present, the test can help show how tumors could respond to treatment. Also called: HRD.

hormone: Proteins or other substances that glands in the body make. They help control how some types of cells and organs work.

hormone-dependent: A cancer that needs hormones to grow, such as some breast cancers and prostate cancers.

hormone receptor: A protein in or on a cell that attaches to a specific hormone. This changes the ability of the cell to grow.

hormone receptor assay: A test that shows if hormones are likely to affect a breast tumor, or if hormones can treat it.

hormone-refractory: No longer responds to hormone treatment.

hormone replacement therapy (HRT): Medicines that replace hormones when the body no longer makes enough of them. They are often used to ease symptoms of menopause, or of other conditions caused by low hormone levels.

hormone therapy: Cancer treatment with medicines that block or change hormones. It helps kill cancer cells that need hormones, or makes them grow more slowly. Also called: endocrine therapy.

hospice: A special type of care for people in the last phase of an illness that cannot be cured. Hospice puts the focus on the quality of life of people with an advanced, life-limiting illness and of their caregivers.

hospice care specialists or team: A team that cares for a patient near the end of life who no longer gets active treatment for a serious illness. The team can include doctors, nurses, other health professionals, social workers, chaplains, counselors and trained volunteers. They work together and put the patient and family at the center. They care for physical, emotional and spiritual needs.

hospice nurse: A nurse on a hospice team who has training in end-of-life care and in control of symptoms. See also: hospice care specialists or team.

hospitalist: A doctor who works only in a hospital.

hot flush or hot flash: A sudden feeling of warmth in the face or body, with red skin (flushing) and sweating. Hormone changes of menopause, or some types of cancer treatment, cause it.

HPV or human papillomavirus [pap-uh-LO-muh vy-rus]: A large group of related viruses. Some of them can cause cancer. Also called: human papilloma virus.

HPV test or human papillomavirus test [pap-uh-LO-muh vy-rus]: A screening test that looks for cervical cancer before there are symptoms. It can be used alone (primary HPV test) or together with a Papanicolaou (Pap) test (co-testing).

hyperalimentation [hi-per-al-ih-men-TAY-shun]: Liquid nutrition given into a vein (intravenously, or IV).

hyperplasia [hi-per-PLAY-zhuh]: A benign overgrowth of cells. Also called: hyperplastic.

hypertension [hi-per-TEN-shun]: High blood pressure.

hyperthermia [hi-per-THERM-ee-uh]: A body temperature that is higher than normal. The word is also used for treatments that use carefully controlled heat for medical purposes.

hysterectomy [hiss-ter-EK-tuh-me]: Surgery to remove the uterus.

I

image cytometry: A lab test that measures how much DNA is in cells. It uses dyes that react with DNA, and a computer does the measuring.

imaging studies: Tests that make pictures of the inside of the body. Imaging tests that help find or stage cancer include x-rays, CT scans, MRI (magnetic resonance imaging), PET scans and ultrasound.

immune system: The body's defense network. Its cells, tissues and organs cooperate to locate invading germs that cause infection and destroy them. It may help locate some cancers too.

immunocytochemistry [im-yuh-no-sy-toe-KEM-iss-tree]: Lab tests that use antibodies to find specific proteins on single cells or on small numbers of cells.

immunology [im-yuh-NAHL-uh-jee]: The study of the immune system, and of how the body fights infection and some other diseases.

immunosuppression [im-yuh-no-suh-PREH-shun]: A weak immune system. A person can be born with it. Cancer, or cancer treatment such as chemotherapy and radiation, can also cause it. It increases the risk of infection.

immunotherapy [im-yuh-no-THER-uh-pee]: Treatment that uses the body's own immune system to fight cancer. It boosts or changes the immune system so that it can find and attack cancer cells.

implant: A man-made device or tissue that is put into the body. Examples are breast implants used in reconstructive surgery, and radiation implants (internal radiation) used to treat cancer. As a verb, it also means to fix something firmly or deeply in place.

impotence [im-puh-tense]: Not being able to get or keep an erection firm enough for penetration. Also called: erectile dysfunction (ED).

incidence [in-sih-dens]: How many new cases of a disease occur in a set period of time.

incidence rate [in-sih-dens rate]: The number of people who get a disease (such as cancer) in a set time period, divided by the number of people at risk of it. The rate can be for a specific group, such as people aged 65 and older. It is usually given as the number of people who get the disease per 100,000 people.

incision [in-sih-zhun]: A cut that a surgeon makes in the skin or other tissue.

incisional biopsy: A biopsy that cuts through the skin to take out part of a tumor. The lab then checks that part for cancer.

inconclusive: Not certain. An inconclusive result cannot show for sure whether a disease, condition or gene mutation is there. It is neither positive nor negative.

incontinence [in-kon-tuh-nence]: Losing some or all control of the bladder or the bowels.

inferior: In anatomy, below another body part, or nearer the feet.

infertility: Not being able to get pregnant after 12 months or more of regular sex. For a woman older than 35, the time is 6 months. Some cancer treatments can cause infertility.

inflammatory bowel disease (IBD): A long-term condition in which the colon stays inflamed for a long time. The two forms are ulcerative colitis and Crohn's disease. IBD raises a person's risk of colorectal cancer.

informed consent [in-FORMD kun-SENT]: A conversation in which a health care provider fully explains a procedure or treatment to a person. It covers the possible risks, benefits and other choices, and answers all the person's questions and concerns. Its purpose is to make sure the person understands the procedure or treatment before they agree to it.

infraclavicular [in-fruh-kluh-VICK-yuh-ler]: Below the collarbone (clavicle).

infusion therapy nurse: A nurse for infusion treatments: chemotherapy, targeted therapy and immunotherapy. Besides giving these drugs, they teach patients and help them cope with the side effects.

ingest [in-jest]: To take something into the body by eating, drinking or absorbing it.

inherited disease: An illness that a person has a higher risk of because they got a gene mutation from a parent at conception.

inpatient: A person who must stay in the hospital for their treatment. Compare to: outpatient.

in situ [in sy-too]: In its original place; limited to one area. It is not thought of as cancer, but it can raise the risk that cancer develops later.

integrated PET/CT: One scan that gives both the detailed picture of a CT scan and the ability of a PET scan to show areas where cells are more active.

integrative therapy: Using standard medical treatment together with some complementary methods. The goal is most often to ease cancer symptoms and treatment side effects.

interferon [in-ter-FEAR-on]: A chemical that cells make naturally to tune the immune system. When a virus, cancer or other threat appears, it turns immune activity up. Some cancers are treated with interferons made in a lab.

interleukins [IN-ter-loo-kins]: A group of proteins (cytokines) that carry chemical signals between white blood cells and tell them to do their jobs.

intermittent hormone therapy: Hormone therapy that is given for a period, then stopped, then started again.

interstitial radiation therapy [in-ter-STIH-shul]: A type of internal radiation (brachytherapy). A radioactive implant is put into the tissue in or near the tumor.

interventional radiologist: A medical doctor who specializes in radiology. They use x-rays, scans and other imaging to guide minimally invasive procedures, such as tumor ablation and embolization.

intracavitary radiation therapy: Radiation given from a radioactive source placed inside a body space (cavity), for example the uterus or the rectum.

intramuscular (IM): Given by injection into a muscle.

intraoperative ultrasound: Ultrasound done inside the body during an operation, once surgery is under way. A computer turns the sound waves into pictures. A surgeon can, for example, hold the probe against the liver to see if cancer is growing within it.

intravenous (IV) [in-truh-VEEN-us]: A way to give fluids and medicines into a vein, through a needle or a thin tube (a catheter).

intravenous pyelogram (IVP) [in-truh-VEEN-us pile-uh-gram]: An x-ray test that uses a special dye to show the structure and function of the urinary system (the kidneys, ureters and bladder).

invasive cancer: Cancer that has grown into the tissues near it.

investigational: Under study. The word often describes medicines or other treatments that are being tested in clinical trials and are not yet available to the general public.

K

Kegel exercises: Exercises that make the muscles of the pelvic floor stronger. They may improve muscle strength and bladder control.

L

lactation [lack-tay-shun]: The making of milk in the breast.

laparoscope [LAP-uh-ruh-scope]: A thin tube with a light and a small camera at its end. The surgeon puts it into the body through a very small cut, to see organs and lymph nodes. Special surgical tools, put in through other small cuts, can then remove the lymph nodes or organs.

laparoscopic surgery [lap-uh-ruh-SKAH-pick]: Surgery done through several small cuts, with a thin lighted tube that has a camera, and with special long tools.

laparoscopy [lap-uh-RAHS-kuh-pee]: Looking inside a body cavity with a laparoscope.

lateral: Away from the middle of the body.

laxative [lack-suh-tiv]: A medicine that makes stool (feces) easier to pass. It prevents or treats constipation. Laxatives work in different ways. Some pull fluid into the intestine or irritate the bowel so that it moves. Others add bulk (such as fiber), make the stool softer, or make it slippery so that it passes more easily.

leiomyoma [lie-o-my-O-muh]: A fibrous growth in the uterus (womb) that is not cancer (benign). By age 40, about 40% of women have one or more. Most cause no symptoms. Depending on how big they are and where they sit, some cause abnormal bleeding from the uterus or other symptoms. Also called: uterine fibroid tumor, or fibroma.

lesion [lee-zhun]: An area of body tissue that injury or disease, such as cancer, has damaged.

leukocyte [LOO-ko-site]: A white blood cell.

leukocytosis [loo-ko-sy-TOE-sis]: A higher number of white blood cells than usual.

leukopenia [loo-ko-PEE-nee-uh]: A low white blood cell count. It is common in people with cancer and is often a side effect of chemotherapy.

leukoplakia [loo-ko-PLAY-key-uh]: White patches on the tongue or on the inside of the cheeks. They are often precancers.

LHRH agonists: See: luteinizing hormone-releasing hormone analogs or LHRH analogs.

libido [lih-be-doe]: Desire for sex.

licensed practical nurse (LPN) or licensed vocational nurse (LVN): A nurse who has finished technical training and passed a basic licensing exam. Under the direction of a registered nurse, they can check vital signs, give some medicines, watch patients and help them with personal hygiene and care, and do other health care tasks.

linear accelerator or linac: A machine that gives external-beam radiation therapy for cancer. It sends one or more beams of radiation, as the treatment plan sets out.

lipoma: A tumor made of fat tissue. It is not cancer.

living will: A legal document in which a person says what should be done if they can no longer make their own health care decisions. It is one type of advance directive.

lobe: One section of an organ. The lungs, brain, liver and thyroid all have lobes.

lobectomy [low-bek-tuh-me]: Surgery to take out one lobe of an organ, usually of the lung.

local anesthesia: See: anesthesia.

local excision [lo-kul eck-si-zhun]: Surgery to take out small cancers on the surface (superficial cancers), for example on the skin or in the colon or rectum.

localized cancer: Cancer that has stayed inside the organ it started in, with no spread to other body parts. Also called: local cancer.

local recurrence: See: recurrence.

local therapy: Treatment directed only at the cancer site, leaving the rest of the body alone. Surgery, radiation, cryotherapy and treatments put on the skin (topical) are all local therapy.

low-dose CT scan: A screening test that looks for signs of lung cancer in people with a higher risk of it.

low-dose rate brachytherapy [brake-ee-THER-uh-pee]: Radioactive seeds (pellets) are placed in the cancer and left there. For weeks or months they release small doses of radiation. A common use is prostate cancer: the seeds are passed into the prostate through the skin of the perineum, the area behind the scrotum. Other names: permanent brachytherapy; LDR brachytherapy. Compare to: temporary brachytherapy, the high-dose rate (HDR) kind.

lower GI series: X-rays of the intestines. A barium enema is given first, then the series of pictures is taken.

lumbar puncture (LP): A thin needle is passed between two bones of the spine (vertebrae) into the spinal canal. Through it, a doctor can draw off a little spinal fluid, or put medicine into the fluid so that it reaches the brain and spinal cord (central nervous system). Also called: spinal tap.

lump: Any mass or swelling in the body.

lupus: An illness in which the body turns on its own organs and tissues and inflames them. It can involve many body parts, and symptoms vary a lot from one person to another.

luteinizing hormone (LH) [LOO-tee-uh-ny-zing]: A hormone from the pituitary gland. It makes the testicles produce testosterone and the ovaries produce estrogen. Also called: LH.

luteinizing hormone-releasing hormone analogs or LHRH analogs [LOO-tee-uh-ny-zing]: Lab-made copies, chemically close to the natural hormone LHRH, that shut down the body's production of testosterone, the male hormone. Doctors sometimes use them to treat prostate cancer. Also called: gonadotropin-releasing hormone (GnRH) analogs.

luteinizing hormone-releasing hormone antagonist [LOO-tee-uh-ny-zing]: A drug type believed to bring testosterone down faster than other hormone drugs, and without the short-term worsening of tumor symptoms known as tumor flare. Other names: GnRH (gonadotropin-releasing hormone) antagonists; LHRH antagonists.

luteinizing hormone-releasing hormone or LHRH [LOO-tee-uh-ny-zing]: A hormone from the hypothalamus, a tiny gland in the brain. It signals the pituitary gland to release luteinizing hormone and follicle-stimulating hormone. That way it controls testosterone in men, and estrogen and progesterone in women. Other names: gonadotropin-releasing hormone; LHRH.

lycopenes [lie-kuh-peenz]: Plant compounds that are thought to help protect health. Tomatoes, pink grapefruit and watermelon contain them. The most current research suggests that a balanced diet with these foods and other fruits and vegetables probably helps more than taking specific substances as dietary supplements.

lymph [limf]: A clear fluid that flows through the lymph vessels all through the body.

lymphadenopathy [limf-A-duh-NAHpuh-thee]: Swollen lymph nodes.

lymphedema [limf-uh-DEE-muh]: Swelling and discomfort when lymph fluid collects in the tissue under the skin. The arms or legs are most often affected, but the face, neck, trunk, abdomen (belly) or genitals can be too. It follows damage to the lymph system, for example from cancer treatment, infection or injury. It may first appear years after treatment and may never go away.

lymph node [limf node]: A small bean-shaped lump of immune tissue, for example lymphocytes. Many lie along the lymph vessels all over the body. They filter germs, cell waste and other harmful material out of the lymph. They help the body resist infection and cancer, although cancer can also travel through them. People sometimes say lymph glands. See also: lymph; immune system.

lymph node biopsy: Taking out all or part of one lymph node to check it under a microscope for cancer spread.

lymph node dissection: Taking out several lymph nodes. The nodes are then checked under a microscope for cancer spread. Also called: lymphadenectomy.

lymphocyte [limf-o-site]: One kind of white blood cell. It helps protect the body from infection.

lymphokine [limf-o-kine]: See: cytokine.

lymphovascular invasion [limf-o-vasc-u-lar invasion]: Cancer that has grown into the small blood vessels or lymph vessels in or around a tumor. It does not mean that the cancer has spread, but the cancer is more likely to spread.

Lynch syndrome: A family (inherited) condition that raises the chance of several cancers: cancers of the colon and rectum, endometrium, ovary, stomach, small intestine, pancreas, kidney, brain, ureter and bile duct. Its older name is HNPCC, short for hereditary non-polyposis colorectal cancer.

M

magnetic resonance imaging or MRI: A test that takes cross-section pictures of the inside of the body. It uses strong magnets, not x-rays. The pictures show on a computer screen and on film. MRI gives pictures of soft tissue that other imaging tests sometimes cannot show well. Also called: magnetic resonance, MR, or nuclear magnetic resonance (NMR) imaging.

malignant [muh-lig-nunt]: Cancerous. Dangerous, or likely to cause death if not treated.

margin [mar-jin]: In cancer surgery or a biopsy, the tissue past the visible edge of the tumor or abnormal tissue. The surgeon removes it with the tumor or abnormal area to try to get all of the cancer.

mass: Any lump or abnormal growth of tissue. It may or may not be cancer.

medial: In anatomy, toward the center of the body.

mediastinoscopy [me-dee-uh-stine-AH-skuh-pee]: A look at the mediastinum (the tissues, organs and lymph nodes between the lungs). The doctor puts a thin, flexible tube under the breastbone (sternum). The tube has a light, a small video camera and a cutting tool at its end. With it, the doctor can see the lymph nodes there and take samples to check for cancer.

mediastinum [me-dee-uh-STY-num]: The area between the lungs, behind the breastbone.

medical oncologist [med-ih-kull on-kahl-uh-jist]: A cancer doctor whose main tools are chemotherapy and other drugs, both to diagnose and to treat. A surgical oncologist, by contrast, treats cancer mostly by operating.

medical power of attorney: See: durable power of attorney for health care.

menarche [men-ar-key or men-ar-key]: A girl's first menstrual period. Having it early, before age 12, raises the risk of some cancers.

menopause [men-uh-paws]: The time of life when the ovaries stop working and menstrual periods stop. Hormone levels usually go up and down during this time, then settle at much lower levels. It usually happens in the late 40s or early 50s. Surgery that removes both ovaries (oophorectomy), or some chemotherapy drugs that destroy ovary function, can also cause it suddenly.

metastasis [meh-tas-tuh-sis]: Cancer that has moved away from its primary site. The cells travel in the blood or the lymph system and settle in other body parts.

metastasize [meh-TAS-tuh-size]: For cancer cells, to spread from where the cancer started (the primary site) to one or more other places in the body. They often spread through the lymph system or the bloodstream.

metastatic [meh-tuh-STAT-ick]: Describes a cancer that has moved beyond its primary site, where it began, into other organs or structures.

microcalcifications: See: calcifications.

micrometastasis [mike-row-muh-TAS-tuh-sis]: A spot of spread cancer that measures under 2 mm, which is less than 1/10 of an inch.

microsatellite instability [my-crow-SAT-uh-lite in-stuh-BILL-uh-tee]: A type of gene mutation that can happen when errors in DNA are not repaired. It is most often linked to colorectal cancer, but other cancers can have it too. It can help guide treatment planning. Also called: MSI.

microvascular surgery: Surgery that uses a microscope to see very small blood vessels and join them to each other.

microwave ablation therapy: A treatment that uses heat to destroy cancer cells in a few places in the body, such as the liver.

millimeter: A metric unit of length, written as mm. It is 1/1,000 of a meter. 10 mm make 1 centimeter, and 1,000 mm make 1 meter. About 25 mm (2.5 cm) make 1 inch. See also: centimeter.

millirem: See: radiation dose.

millisievert: See: radiation dose.

monoclonal antibodies [ma-nuh-KLO-nuhl]: Lab-made antibodies that attach to specific antigens (substances the immune system can recognize). Each one is made to attach to only one antigen. They have several uses in finding and treating cancer and other diseases.

morbidity [mor-bid-ih-tee]: How many people in a group have a disease or condition.

morphology [mor-fol-uh-jee]: In cancer, how cells look under a microscope. This includes their shape, structure, pattern, color and other features.

mortality [mor-tal-uh-tee]: The rate of death from a disease in a group of people over a set period of time.

mortality rate [mor-tal-uh-tee rate]: Deaths from a disease, such as cancer, over a set time, divided by the number of people at risk during that time. It is usually stated as deaths per 100,000 people. Also called: death rate.

mRNA or messenger RNA: See: RNA or ribonucleic acid.

mucinous carcinoma [mew-sin-us car-sin-O-ma]: A carcinoma made of cancer cells that produce mucus.

mucositis [mew-ko-site-us]: A sore, inflamed mucous membrane, for example in the mouth.

mucous membrane: A moist lining on the inside of some organs and body spaces. The mouth, nose, throat, digestive system and vagina have one. Also called: mucosa.

mucus [mew-kus]: The thick, slippery fluid that mucous glands make.

multi-cancer early detection tests (MCED): Blood tests that search for bits of DNA, RNA or protein that could signal cancer. They may find some cancers early. They are new, though, and researchers still need to learn how useful they are for screening.

multi-drug resistance (MDR): When cancer cells change so that anti-cancer drugs work less well.

multiple sclerosis [MUL-tih-pul skleh-ROH-sis]: A disease in which the immune system attacks the nerve fibers of the brain and spinal cord. It causes symptoms such as weakness, numbness, tingling and vision problems.

muscularis mucosae [mus-kyu-LAIR-is myoo-ko-say]: The inner muscle layer of the intestine (digestive tube). It is between the mucosa and the submucosa.

muscularis propria [mus-kyu-LAIR-is pro-pree-uh]: The muscle layer that covers most of the intestine (digestive tube). It is the layer farthest from the center of the tube. Going outward from the opening, it is under the submucosa. Past it is a thin layer of tissue called the subserosa, which covers the colon but not the rectum.

mutation [mew-tay-shun]: An abnormal change in a gene. Genes are stretches of DNA that instruct cells, including when to grow and divide. Most such changes do not lead to cancer. But experts think every type of cancer comes from gene changes.

myeloablative treatment [my-uh-lo-uh-BLAY-tiv]: Treatment that wipes out a person's marrow so that they can then receive a transplant of stem cells or marrow. See also: conditioning treatment; bone marrow.

myeloid leukemia [my-uh-loid loo-key-me-uh]: A blood cancer that begins in the immature cells that should grow into the various kinds of blood cells. It is either chronic (CML) or acute (AML). AML has many subtypes. Some carry genetic changes that affect how likely treatment is to succeed. Other names: non-lymphocytic leukemia; myelogenous leukemia; myelocytic leukemia.

N

naturopathic doctor (ND): A practitioner, not a medical doctor (MD), trained in therapies meant to support the body's own healing. Each state sets its own education and licensing rules for NDs.

necrosis [nuh-crow-sis]: The death of one or more body cells. "Necrotic" describes tissue that has died.

needle aspiration [need-ul asp-er-A-shun]: Using suction to draw out liquid, gas or bits of tissue. A needle goes into the cyst or tumor, and suction pulls up (aspirates) samples to look at under a microscope.

needle biopsy [need-ul by-op-see]: Taking out fluid, cells or tissue with a needle to look at under a microscope. The main types are fine needle aspiration (FNA) and core needle biopsy.

needle localization [need-ul lo-cull-ih-ZAY-shun]: A procedure that guides a surgical biopsy when a lump is hard to find, or when an x-ray shows suspicious areas but no clear lump. A thin needle goes into the area, and x-rays guide it to the suspicious spot. The surgeon then follows the path of the needle to find the abnormal area and remove it. See also: biopsy, x-ray.

negative: A lab or pathology result that did not find the change or problem the test looked for. For example, a biopsy that is negative for cancer found no cancer in that sample.

negative margin: See: surgical margin.

neoadjuvant therapy [nee-o-AD-juh-vunt]: Treatment that comes first, before the main treatment. One example: hormone therapy can shrink a tumor ahead of brachytherapy so the brachytherapy works better. Compare to: adjuvant therapy.

neonatologist [nee-o-nay-TAHL-uh-jist]: A doctor who specializes in caring for newborn babies. This is until about 6 weeks of age, and often longer for babies born early.

neoplasia [nee-o-PLAY-zee-uh]: Abnormal, uncontrolled growth of cells. It can be benign (not cancer) or malignant (cancer).

neoplasm [NEE-o-plaz-um]: An abnormal growth (tumor) that can be benign (not cancer) or malignant (cancer). It can be called a neoplastic tumor.

nephrologist [neh-frahl-uh-jist]: A doctor who specializes in kidney (renal) diseases.

neuropathy [nur-ah-puth-ee]: See: peripheral neuropathy.

neurosurgeon [nur-o-SUR-jun]: A doctor who specializes in surgery on the nervous system, which includes the brain, spinal cord and nerves.

neutropenia [new-trow-PEEN-ee-uh]: Too few neutrophils in the blood. Neutrophils are the white blood cells that protect against most infections. The risk of infection rises the further the count drops and the longer it stays down.

neutrophils [new-trow-fills]: A type of white blood cell that fights bacterial infections.

nocturia [nok-toor-ee-uh]: Needing to urinate too much at night.

nodal status: Whether the cancer has spread to the lymph nodes (node-positive) or not (node-negative).

node: See: lymph node.

nodule [nod-yool]: A small, solid lump that can be felt. The word sometimes also means a small tumor seen on an x-ray.

non-steroidal anti-inflammatory drugs [non-steer-OYD-uhl an-tie-in-FLAM-uh-tor-ee or an-tee-in-FLAM-uh-tor-ee]: Medicines that lower pain, inflammation and fever. Before you take an NSAID, ask your doctor, pharmacist or nurse whether it is safe with your other medicines, and for how long you can take it. Also called: NSAIDs.

nuclear medicine: The medical field that finds and treats illness with radioactive substances (radioisotopes).

nuclear medicine scan: A test that finds tumors, shows how far a cancer has spread, and checks whether treatment is working. A small amount of a radioactive substance (an isotope) goes into the bloodstream. The isotope collects in certain organs. A special camera then takes a picture of the organ that shows areas of disease.

nucleus [new-klee-us]: The center of a cell. It holds the DNA, and the DNA copies itself there. When pathologists study the size and shape of the nucleus under a microscope, it can help them tell cancer cells from normal cells.

nulliparous [nuh-lip-uh-rus]: Never having given birth.

nurse anesthetist: A nurse with advanced education and training in anesthesia: giving drugs or gases that remove all feeling or relieve pain. This is usually done for surgery.

nurse practitioner [nurs prak-tih-shun-er]: An advanced practice registered nurse (APN or APRN). They hold a master's or doctoral degree and a special certification, and they have extra training and clinical experience in one area of care. Working closely with a doctor, they help diagnose problems and manage patients' care.

nutritionist: A title that people sometimes use to mean dietitian. But the education needed to be a nutritionist is different from state to state. See also: dietitian or registered dietitian.

O

obesity: Being overweight to a certain level. In general, this means a body mass index (BMI) above 30. BMI is calculated from height and weight.

occult [uh-kult or o-kult]: Hidden. In cancer, it can mean a cancer whose starting place is not known. It can also mean small amounts of blood in stool that only special tests can find.

occupational therapist [ok-you-PAY-shun-uhl]: A licensed therapist with special training. They help people with limits in how their body works to build, recover and improve the skills they need for daily life and work. They also help prevent disability and keep people healthy. Their work includes assessment, treatment and advice.

off label: Using a drug in a way that is not on its FDA-approved label. For example, for a different disease, by a different route or at a different dose.

omentum [o-men-tum]: A fatty apron of tissue inside the belly (abdomen). It drapes over the stomach, the intestines and other organs.

oncogenes [on-kuh-jeenz]: Changed (mutated) forms of normal genes called proto-oncogenes, which make cells grow and divide. When a proto-oncogene mutates into an oncogene, cells can grow out of control. This can lead to cancer.

oncologist [on-kahl-uh-jist]: A doctor who is an expert in finding and treating cancer. See also: cancer care team.

oncology [on-kahl-o-jee]: The area of medicine that finds and treats cancer.

oncology clinical nurse specialist [on-kahl-o-jee]: An expert cancer nurse. This registered nurse holds a master's degree in cancer nursing. Their work can include getting treatments ready and giving them, checking on patients, prescribing and giving supportive care, and teaching and counseling patients and families. See also: cancer care team.

oncology social worker [on-kahl-o-jee]: A social worker with a master's degree who arranges and gives non-medical care. Patients and their families get counseling and help from them with the practical problems a cancer diagnosis can bring. Examples are money worries, a place to stay when treatment is far from home, and child care. See also: cancer care team.

oncoplastic surgery: Newer methods that join cancer surgery with plastic surgery methods.

ophthalmologist [off-thuhl-MAHL-uh-jist]: A doctor who is an expert in eye diseases.

oral: About the mouth. A medicine you swallow is an oral medicine. Cancer of the mouth is oral cancer.

oral and maxillofacial surgeon [max-ill-o-FAY-shul]: A surgeon who is an expert in surgery of the mouth, jaw and face.

oral contraceptives: Birth control pills. They contain estrogen, a progesterone-like substance called progestin, or both.

orthopedic surgeon [or-thuh-pee-dik]: A surgeon who is an expert in diseases and injuries of the muscles, joints and bones (the musculoskeletal system).

osteoporosis [os-tee-o-puh-RO-sis]: Thinning of the bones. The bones get weaker and break (fracture) more easily. Cancer treatments can also cause it.

ostomy [os-tuh-me]: An opening that surgery makes from inside the body to the outside. Examples are a colostomy, ileostomy, tracheostomy or urostomy. Also called: stoma.

ostomy nurse: See: enterostomal therapist.

otolaryngologist [o-toe-lair-in-GOL-uh-jist]: An ear, nose and throat doctor, who treats illness and injury in these areas. Also called: ENT (for ears, nose and throat) or head and neck doctor.

outpatient: Someone who gets care but does not stay overnight in the hospital. Compare to: inpatient. See also: ambulatory.

ova: Eggs, the reproductive cells a woman releases while she is fertile. A sperm must fertilize an egg before it can grow into a baby. One egg is called an ovum.

ovarian ablation: Treatment that lowers or stops the estrogen the ovaries make. It can be done by removing the ovaries, or with radiation therapy, hormone therapy or other medicines.

P

p53: An important tumor suppressor gene. Normally, it makes damaged cells die. When it does not work correctly, the risk of many types of cancer goes up.

pain specialists: Doctors, nurses or pharmacists who are experts in controlling pain. In many places, a team of health professionals is available to help with pain.

palliative care nurse: A nurse who works with the patient and the cancer care team to ease symptoms. Examples are pain, nausea and tiredness (fatigue). This help is available at every stage of a serious illness. See also: palliative care specialists or team.

palliative care or treatment [pal-ee-uh-tiv]: Care that makes quality of life better by controlling the symptoms of a serious illness and the side effects of its treatment. A person can get it at any time during an illness when symptoms need control. It makes the patient more comfortable, but it does not cure the disease.

palliative care specialists or team [pal-ee-uh-tiv]: Doctors, nurses, pharmacists and other health professionals who work together to control symptoms such as pain, nausea or fatigue. This team can help any patient of any age with a serious illness. It often works with the cancer care team to control side effects during and after treatment. It can help at any stage of cancer, from diagnosis, through treatment, to the end of life.

palpation [pal-pay-shun]: Examining with the hands. A palpable mass is a lump that can be felt.

pancolitis [pan-ko-LITE-us]: Ulcerative colitis in the whole colon.

papillary tumor [PAP-uh-lair-ee]: A tumor whose cancer cells form tiny finger shapes under a microscope. This look is common in some tumors of the thyroid gland, ovaries, uterus and other organs.

papilloma [PAP-uh-lo-muh]: A growth that is benign (not cancer).

Pap test or Pap smear: A test that takes cells from the cervix and looks at them with a microscope for cancer or pre-cancer cells. A test for human papillomavirus (HPV) is often done at the same time.

pathologic stage: See: stage.

pathologist [path-all-uh-jist]: A doctor who is an expert in finding and sorting diseases with lab tests and by looking at tissue and cells with a microscope. The pathologist decides if a tumor is cancer. If it is, they find the exact cell type (where it started) and the grade (how fast it will probably grow).

patient or nurse navigator: A person who guides patients and families through complex health care systems. They help patients work with the rest of the cancer care team and get past problems that block care, so the patient can complete treatment. Navigators can be trained lay people with experience, or health professionals such as nurses or social workers.

pediatrician [pee-dee-uh-TRISH-un]: A doctor who is an expert in the care of children and teens. This includes preventing illness, primary health care and treating diseases.

pediatric oncologist [pee-dee-at-trick on-kahl-uh-jist]: A cancer doctor for young people. They treat children and teens, sometimes up to age 21.

pelvic examination [pell-vick ex-am-in-A-shun]: A doctor checks a woman's uterus and the other organs in her pelvis. This exam helps find cancers of the reproductive organs. The doctor looks at the outside parts, then feels (palpates) the inside organs, such as the ovaries and uterus.

percent-free PSA (fPSA): Some prostate-specific antigen (PSA) floats free in the blood, and some is bound to blood proteins. fPSA is the free share. It tends to be lower in men with prostate cancer than in men without it, so a low result can point to the need for a biopsy.

perforation [per-fuh-RAY-shun]: A hole in the wall of a hollow organ, such as the bladder or lung.

perineum [pair-uh-NEE-um]: The perineal area. In males it lies between the anus and the scrotum. In females it lies between the anus and the vagina.

perineural invasion [pair-uh-NOO-rul]: Cancer cells that grow into the areas around nerves.

peripheral neuropathy [peh-RIH-feh-rul noor-AH-puh-thee]: Damage to nerves, often first in the hands or feet. It can bring numbness, tingling, burning, pain, weakness, cramps, and trouble sensing heat and cold. Possible causes are injury, infection, illness (for example cancer, diabetes, kidney failure or poor nutrition) and medicines such as chemotherapy. Also called: neuropathy.

peritoneum [pear-i-tuh-NEE-um]: A thin layer (membrane) that lines the inside of the belly (abdomen) and wraps most of the organs there. The space inside it is the peritoneal cavity.

permanent brachytherapy: See: low-dose rate brachytherapy.

permanent section: Biopsy tissue that is prepared to be seen with a microscope. The tissue is soaked in formalin, treated with chemicals, set in wax, cut into very thin slices, put on a slide and stained. This takes several days. It gives the pathologist a clear view of the cells, to see if cancer is there.

PET scan or positron emission tomography [pahs-uh-trahn ee-mish-uhn tom-ahg-ruh-fee]: An imaging test. A radioactive sugar goes into the body, and cancer cells often absorb more of it than normal cells do. This can make cancer cells stand out. Doctors use the scan to find tumors, or to check how a tumor reacts to treatment.

pharmacist (RPh or PharmD): A licensed health professional with at least a bachelor's degree in pharmacy. A pharmacist checks that a patient's medicines and treatments are safe and do their job. See also: pain specialists, palliative care specialists or team.

pharmacogenetics: The study of how one gene can change a person's response to a medicine or treatment.

pharmacogenomics: The study of a person's whole genetic makeup to find which medicines and doses will work best for them.

pheresis [fuh-ree-sis]: See: apheresis.

photocoagulation or photoablation [foe-toe-ko-ag-yu-LAY-shun or foe-toe-uh-blay-shun]: Surgery with a laser beam that destroys tissue or seals tissue or blood vessels. It is used more often to relieve blockages than to cure cancer.

photodynamic therapy [foe-toe-die-NAM-ick]: Treatment that kills cancer cells with light and a special drug. These drugs are sometimes called photosensitizing agents. Also called: PDT.

photon beam radiation therapy [foe-ton]: The standard type of radiation for external beam radiation treatment.

physical therapist: A licensed health professional with at least a bachelor's degree in physical therapy. They examine, test and treat physical problems. They use exercise, heat, cold and other methods to bring back or keep the body's strength, movement and function.

physician assistant/associate (PA): A certified, licensed medical professional with a master's or doctoral degree. PAs practice medicine in teams with doctors and other health professionals and give many types of care. Depending on training and experience, they may focus on some diseases or areas of medicine.

physiologic [fiz-ee-o-LA-jick]: About the processes of the body or its systems. It can also mean that a body function or organ is normal.

phytonutrients [fie-toe-NOO-tree-ents]: Compounds in plants, such as carotenoids, lycopene, resveratrol and phytosterols, that are thought to help protect health. Also called: phytochemicals.

placebo [pluh-see-bo]: A fake pill or treatment. Studies (clinical trials) can use it to compare a treatment with no treatment. A placebo is not used when a proven treatment exists. Then the new treatment is compared with the proven one.

plastic or reconstructive surgeon [re-kon-STRUCK-tiv]: A surgeon who is an expert in changing how a body part looks, or in rebuilding or replacing body parts that were removed or injured. To rebuild a part, the surgeon may use the patient's own tissue or a special material that keeps its shape over time. Also called: plastic and reconstructive surgeon.

platelet [plate-let]: A blood cell that stops bleeding. After an injury, platelets plug the holes in damaged blood vessels. Chemotherapy and radiation therapy can make the count fall. A low count is called thrombocytopenia, and it can lead to heavy bleeding.

pleurodesis [plu-rah-dis-sis or plur-o-DEE-sis]: A procedure that removes fluid that has collected between the lungs and the pleura. A substance is then put between the layers to join them, so the fluid does not come back.

ploidy [ploy-dee]: How many sets of chromosomes a cell has. A cancer is diploid (dip-loyd) when it has 23 pairs, like normal cells. It is aneuploid (an-you-ployd) when it has more or fewer.

polycythemia vera [pah-lee-sy-THEME-e-uh vair-uh]: A long-term blood disorder in which the bone marrow overproduces red cells, white cells and platelets. Its main sign is extra red cells, which raises the hemoglobin level. Later, the high platelet count can cause more trouble, because the "thickened" blood can form clots. The disorder is not a true cancer, but after many years it often becomes acute myelogenous leukemia (AML).

polyp [pah-lip]: A growth that sticks out from the inner lining (mucous membrane) of an organ, for example the colon, rectum, uterus or nose. Some polyps are benign (not cancer) and some are malignant (cancer).

polypectomy [pah-lup-ECK-tuh-me]: Surgery or a procedure to remove a polyp.

population [pop-u-la-tion]: A group of people who usually share one or more traits, such as age, sex or disease.

portography [por-tahg-ruh-fee]: A test that looks for cancer that has spread from the colon or rectum to the liver. A dye goes into the liver's portal vein, then a CT (computed tomography) scanner takes cross-section x-ray pictures of the veins.

positive margin: See: surgical margin.

posterior [post-eer-ee-uhr]: Toward the back. It can refer to an organ or to the body.

poultice [pole-tiss]: A soft paste or thick liquid, usually heated, put on a cloth and placed on a painful or inflamed area. Folk medicine and home remedies often use herbs, leaves or foods for it.

pre-cancerous: Changes in cells that can become cancer, but do not always.

predisposition [pre-dis-puh-ZISH-un]: A higher chance of getting a disease. For example, people with some gene changes (mutations) or a family history are more likely to get some types of cancer.

pre-malignant: See: pre-cancerous.

prevalence [preh-vul-uns]: The number of living people who have ever had a cancer diagnosis. This includes people diagnosed in the past and people diagnosed recently.

prevention: Lowering cancer risk. Ways to do this are to avoid or reduce contact with things known to cause cancer, to change conditions that add to cancer (such as obesity or lack of exercise), and to use medicines that block cancer from developing. For example, lifestyle changes such as quitting smoking lower the number of people who get lung and other cancers.

previvor: A person who has a higher risk of cancer but has not had a cancer diagnosis. Previvors have an inherited gene (genetic) mutation, a family history of cancer, or other known risk factors.

primary care physician or provider: The doctor a person usually sees first for a new symptom or health problem. This can be a general practitioner, family doctor, gynecologist, pediatrician or internal medicine doctor (internist).

primary HPV test: See: HPV test or human papillomavirus test.

primary site: Where a cancer first starts. Cancers usually take the name of their starting organ. A cancer that begins in the breast stays breast cancer even after it spreads (metastasizes) to other places, such as the bones or lungs.

primary treatment or primary therapy: The first treatment for a cancer.

progesterone [pro-jes-ter-own]: A female sex hormone that the ovaries release in each menstrual cycle. It prepares the uterus (womb) for pregnancy and the breasts for making milk (lactation).

progesterone receptor assay: A test on breast cancer cells. It shows if progesterone affects the cancer and if the cancer may respond to hormone therapy.

prognosis [prog-no-sis]: The likely course of a disease. This includes the chance of recovery and the chance that the cancer comes back.

progression: Disease that grows or spreads, with or without treatment.

prolactin: A hormone from the pituitary gland that causes the breasts to make milk.

proliferative [pro-lih-fer-uh-tiv]: Fast growth, or a rising number of new cells.

prospective cohort study: A study that follows a cohort, a group of people with shared traits, for many years. Researchers gather data before any member has cancer ("prospective"). They then compare the data to learn how particular traits or risk factors change how often diseases such as cancer occur.

prosthesis [pros-thee-sis]: A man-made replacement for a missing body part. Also called: prosthetic.

protein [pro-teen]: A large molecule built from a chain of small units called amino acids. Proteins do many important jobs, both inside the body's cells and outside them.

protocol [pro-tuh-call]: A formal plan. For example, a description of which treatments a patient will get and exactly when to give each one.

proton beam therapy: A form of radiation therapy that kills tumor cells with protons, which are particles with a positive charge. It does less radiation harm to the healthy tissue around a tumor. Doctors use it for cancers of the prostate, spine, brain, eye, lung, and head and neck.

proximal: Closer to the middle of the body. A body part is proximal when it sits nearer the center than another part.

PSA density (PSAD): The prostate-specific antigen (PSA) level divided by the size of the prostate. A higher PSAD means cancer is more likely.

PSA doubling time (PSADT): How long the blood level of prostate-specific antigen (PSA) takes to become twice as high. This can sometimes help show if a man has prostate cancer, or if it has returned (recurred).

PSA or prostate-specific antigen: A protein that the prostate gland makes. Most of it is in semen, and a small amount is in the blood. Blood tests for PSA can be used to screen for prostate cancer, to watch for changes in prostate cancer during observation or treatment, and to check if prostate cancer has come back after treatment ends.

PSA velocity (PSAV): A measure of how fast the prostate-specific antigen (PSA) level goes up over time.

psychiatrist [sy-ky-uh-trist]: A medical doctor for mental, emotional and behavior disorders. They study what causes these disorders, and they treat and prevent them. They counsel patients, and they can also prescribe medicines or other treatments.

psychologist [sy-koll-uh-jist]: A health professional trained in clinical psychology, with a graduate degree in psychology. They assess how a person is doing mentally and emotionally. They test and counsel people who may have an emotional or mental health problem.

psychosocial [sy-ko-SO-shul]: About the mental and social sides of health, disease, treatment or rehabilitation.

PTEN: A gene that normally keeps cell growth in check. An inherited change in it causes Cowden syndrome. This rare disorder raises the risk of breast tumors, both benign and cancerous. It is also linked with growths in the thyroid, uterus, ovaries and digestive tract.

public health intervention: Steps to make the health of a population better. For example, an intervention can work at the person, community and system levels to get more people screened for cancer and vaccinated against HPV.

pulmonologist [pull-muh-NAHL-uh-jist]: A doctor with special experience and knowledge in finding and treating lung (pulmonary) conditions and diseases.

Q

quality of life: How much a person enjoys life overall. It includes their sense of well-being and their ability to do the things that matter to them.

R

radiation: Energy that travels as electromagnetic waves or as particles. Nature produces some, for example radon gas from the ground and rays from outer space. People make some on purpose, for example x-rays and microwaves. Medicine uses it to find problems (x-rays, CT scans) and to treat disease (radiation therapy for cancer).

radiation dose: The amount of radiation that something, such as body tissue, receives. Several units are used:

• rad (radiation absorbed dose): a basic unit for how much radiation body tissue absorbs. The gray has mostly replaced it.
• gray (Gy): the newer international unit for absorbed radiation. One gray equals 100 rads.
• rem (roentgen equivalent man): an older unit of exposure that shows the chance of health effects, based on both the dose and the type of radiation. The sievert has replaced it.
• sievert (see-vert), Sv: the newer standard international unit of exposure that shows the chance of health effects, based on both the dose and the type of radiation. One sievert equals 100 rem.

radiation oncologist [ray-dee-A-shun on-kahl-uh-jist]: A doctor who is an expert in treating cancer with radiation. See also: cancer care team.

radiation oncology nurse: A nurse who looks after people having radiation treatment for cancer. Their work is patient teaching, giving the treatments, and easing side effects.

radiation proctitis [ray-dee-A-shun prok-tie-tis]: Irritation of the anus and rectum caused by radiation therapy to the pelvis. Problems can include pain, frequent or urgent bowel movements, bleeding, long-term burning and leakage from the rectum.

radiation therapist [ray-dee-A-shun ther-uh-pist]: The trained person who runs the radiation therapy machines. They often help the patient lie in the correct position, then give the treatment.

radiation therapy [ray-dee-A-shun ther-uh-pee]: Treatment with high-energy rays or particles that destroy or damage cancer cells. A machine outside the body can give it (external radiation). Radioactive material put in the tumor can also give it (brachytherapy or internal radiation). It can shrink a cancer before surgery, kill cancer cells that remain after surgery, or be the main treatment. It can also be palliative (non-curative) treatment for advanced cancer.

radiation therapy nurse [ray-dee-A-shun ther-uh-pee nurse]: A registered nurse who is an expert in caring for patients who get radiation therapy. This nurse may teach the patient about the treatment before it starts and help control side effects.

radiocontrast dye [ray-dee-o-CON-trast]: Any material used in imaging tests such as x-rays, MRIs and CT scans to show the outline of the body parts being examined. It may go into a vein, or you may drink it. Some people react to it. Before the procedure, tell your doctor and the technologist about any allergies, or any past reaction to this dye. Also called: dye, contrast dye, radiocontrast medium.

radiofrequency ablation [ray-dee-oh-free-kwin-see uh-blay-shun]: Treatment that heats and destroys abnormal tissue with strong radio waves. The doctor uses ultrasound or a CT (computed tomography) scan to steer a thin probe, shaped like a needle, into the tumor. A high-frequency current from the probe heats the cancer cells until they die. It is sometimes used for liver tumors. Researchers are testing it in other parts of the body. Also called: RFA.

radioisotope [ray-dee-oh-EYE-suh-tope]: An unstable compound. As it breaks down, it gives off radiation energy. Imaging tests use radioisotopes to find cancer, and some treatments use them to fight cancer.

radiologic technologist [ray-dee-uh-LAH-jick teck-nah-luh-jist]: A health professional who takes x-rays and other imaging tests. They get the patient into position, take and develop the images, and check their quality. A radiologist then reads the images.

radiologist [ray-dee-AH-luh-jist]: A doctor with special training in finding diseases by reading x-rays and other imaging tests that make pictures of the inside of the body.

radionuclide bone scan [ray-dee-oh-NOO-klide]: See: bone scan.

radiopharmaceuticals [ray-dee-oh-farm-uh-SUIT-ih-kulz]: Drugs that contain radioactive elements or radioisotopes. They go into a vein (intravenously or IV) to treat some cancers, such as thyroid, bone and prostate cancer. They also treat bone pain from cancer that has spread to the bones.

radiotherapy: See: radiation therapy.

randomized or randomization: In a clinical trial, chance decides which group each person joins, so that treatments can be compared fairly. Every person is equally likely to land in the treatment group or the control (comparison) group. This lowers bias. For example, it keeps the healthiest people from all ending up in one treatment group.

recessive allele: See: allele.

recurrence: Cancer that returns after treatment, at a time when tests could no longer find it. It can return in the place where it began or somewhere else in the body.

red blood cells (RBCs): Blood cells that contain hemoglobin, which carries oxygen to all the cells of the body. The bone marrow makes them. A low red blood cell count, called anemia, is a common side effect of many cancer treatments.

re-excision: Another operation to take out cancer that was left behind. A surgeon may do it when cancer cells show up at the edge of the tissue removed the first time.

refractory [re-frack-tuh-re]: No longer responding to a specific treatment.

regimen [reh-juh-men]: A treatment plan that gives the exact doses, schedule and length of treatment. It can include different medicines and other methods, such as radiation.

regional involvement or regional spread: Cancer that has moved beyond its primary (first) site into lymph nodes, organs or tissues close by. It has not reached distant parts of the body.

registered nurse (RN): A nurse who finished a college nursing program and passed a national licensing exam. RNs assess, teach and treat patients, families and whole communities. They can work, and earn certification, in nearly every health field. With more schooling they can become advanced practice nurses (APN or APRN), for example clinical nurse specialists, nurse practitioners or nurse anesthetists.

regression [re-gresh-un]: A decrease in the size of a tumor or in the amount of cancer in the body.

rehabilitation [re-huh-bill-ih-TAY-shun]: Steps that help a person adjust, heal and go back to a full, active life after an injury or illness. It can include physical help (such as prostheses, exercise and physical therapy), counseling and emotional support.

relapse [re-laps]: Cancer or another disease that comes back after a time when its signs and symptoms got better.

relative risk [REH-luh-tiv risk]: A comparison of how likely one group is to get a disease versus another group, based on differences in behavior or conditions. Say a factor halves the risk of some cancer: the relative risk is then 50% lower. The real change for one person depends on their starting (absolute) risk. If someone starts at 10% (1 in 10) and the factor halves it, their relative risk falls by 50%, but their absolute risk falls by only 5% (from 10% down to 5%).

relative survival rate [REH-luh-tiv ser-VY-vul rayt]: A comparison of how many people with a disease, such as a type of cancer, are still alive after a set time, against a similar group without that disease. It allows for deaths from other causes. It is usually a percentage. For example, a 50% 5-year relative survival rate means that, after 5 years, people diagnosed with that cancer have half the chance of being alive that people without it have.

rem: See: radiation dose.

remission [re-MISH-un]: A time when cancer is under control or responding to treatment. Complete remission means every sign and symptom is gone and tests find no cancer cells. Partial remission means the cancer is smaller but still there. Remission is not always the same as a cure.

replicate [REP-lih-kate]: To make exact copies.

rescue treatment: In cancer care, procedures or treatments, such as a bone marrow transplant, that "rescue" the patient's immune system and blood-forming organs from the effects of high-dose chemotherapy.

research continuum: Research of every kind, from the lab to the patient (often called "bench to bedside"). It takes place in labs, in clinical trials, with care providers, inside health systems and out in communities.

resection [re-sek-shun]: Surgery that removes part or all of an organ, tissue or other body structure.

resectoscope [re-SEK-tuh-scope]: A slim, stiff scope with a wire loop on its tip. Doctors use it to cut away abnormal tissue or tumors in the prostate or bladder, for example in transurethral resection of the prostate (TURP) or of a bladder tumor.

respiratory therapist [RES-per-uh-tor-ee ther-uh-pist]: A specialist who helps people with breathing problems. The work can include giving breathing treatments and looking after patients on ventilators (machines that breathe for them). A certified respiratory therapy technician (CRTT) may also examine patients, measure how well their lungs work, and set up and look after equipment like ventilators.

respite care [res-pit]: Short-term care for a sick person who is usually cared for at home, given in a nursing home or hospital. It gives the regular caregiver a break (respite).

response: Improvement after treatment.

retrograde ejaculation [ret-tro-grade e-jack-you-LAY-shun]: A condition in which semen goes into the bladder during orgasm, instead of leaving the body through the penis. The usual cause is damage to valves in the bladder or to nearby nerves after some surgeries for prostate, testicular, bladder and colorectal cancers. Also called: dry orgasm.

risk factor: Something that makes a disease such as cancer more likely. Each cancer has its own risk factors. Strong sunlight on unprotected skin raises the risk of skin cancer. Smoking raises the risk of cancers of the lung, mouth, throat and other places. People can control some risk factors, such as smoking and inactivity. They cannot change others, such as their age or gene mutations present from birth.

RNA or ribonucleic acid [ri-bo-noo-KLEE-ick a-sid]: A nucleic acid in all cells that carries genetic information copied from DNA. Its main job is to turn the information stored in DNA into proteins. Messenger RNA (mRNA) carries the message between the DNA and the ribosomes, the parts of cells that make proteins.

RT-PCR or reverse transcription polymerase chain reaction [re-verse tran-scrip-shun puh-lim-er-ace]: A highly sensitive test for genetic changes (mutations) linked to cancer, such as those found in some cancers. It can spot a few cancer cells in a blood or tissue sample when other tests would not. The test examines ribonucleic acid (RNA) for changes that can guide treatment choices and show how well treatment works.

S

saline [say-lean]: A mix of salt and water.

sarcoma [sar-ko-muh]: A cancer that begins in connective tissue. Examples of this tissue are bone, muscle, fat and cartilage.

scan: A test that makes detailed pictures of the inside of the body and its organs. CT scans, MRI scans and nuclear medicine scans (for example, bone scans and liver scans) are all scans.

scanxiety: Worry (anxiety) that a person feels before, during or after imaging scans. The amount of distress is different for each person. Some people feel very uneasy, with trouble breathing or a racing heart. Other people feel only a small amount of concern.

scintillation camera [sin-till-LAY-shun]: A device for nuclear medicine scans. It finds radioactivity in the body and makes pictures from it. Doctors use these pictures to help diagnose cancer and other diseases.

screening: Tests, exams or procedures that look for cancer in people who have no symptoms. Screening makes it more likely that some cancers are found early. At that time they are small, have not spread, and can be easier to treat. Diagnostic testing is different: it tries to find the cause of symptoms that a person already has.

secondary tumor: A tumor that forms when cancer spreads (metastasizes) away from the place where it began (the primary site).

second cancer: A new cancer, not related to the first one, in a person who already had a different cancer. For example, a person who had breast cancer later gets colorectal cancer. This is not the same as the first cancer coming back after treatment (recurrence).

sedation [suh-day-shun]: Making a person sleepy, calm or relaxed. Doctors often give sedation medicines together with medicines that numb an area, for a procedure or for some types of surgery.

sedentary: Doing little physical activity while awake. A sedentary person spends much of the time sitting, reclining or lying down, and is physically inactive for long periods.

segmental resection [seg-men-tuhl re-sek-shun]: Surgery that removes part of an organ, or a tumor with some normal tissue around it. For colon cancer, the surgeon removes the cancer, a length of normal colon on each side of it, and the nearby lymph nodes. Then the surgeon joins the remaining parts of the colon again. For lung cancer, the surgeon removes a section of a lobe of the lung. Also called: segmentectomy.

selective estrogen receptor modulator (SERM): A hormone therapy drug. It stops estrogen from signaling breast cancer cells to grow and divide. In breast cells it acts against estrogen, but in other tissues, such as the uterus and the bones, it acts like estrogen. It can treat breast cancer in women before or after menopause. Tamoxifen is the SERM that doctors use most.

semen [see-muhn]: The fluid that comes out during male orgasm. It holds sperm and seminal fluid.

sentinel lymph node biopsy [sen-tin-uhl]: For some types of cancer, this procedure replaces routine removal of many lymph nodes (lymph node dissection). During surgery, the doctor injects blue dye, a radioactive substance, or both, into the tumor. The first lymph node that takes up the dye (the sentinel node) is removed and checked. If that node has no cancer cells, the surgeon removes fewer nodes.

sex therapist: A mental health professional with special training in counseling about sexual changes, sexual problems and communication, for example after cancer treatment. This person can be a licensed psychiatrist, psychologist, social worker, clinical nurse specialist or nurse practitioner. A sex therapist often works with both partners, not only one person.

side effects: Effects of treatment that a person does not want. Examples are hair loss, low blood counts, fatigue (extreme tiredness) and rashes.

sievert (Sv): See: radiation dose.

sigmoidoscope [sig-MOYD-uh-scope]: A flexible tube with a light and a small video camera at its end. It is about as thick as a finger. The doctor puts it through the anus into the rectum and the lower colon. With it, the doctor can see all of the rectum but less than half of the colon, and looks for cancer or polyps (small growths that can turn into cancer).

sign: A change in the body that another person can see or measure, for example fever or bleeding. Compare to: symptom.

simulation: Planning for radiation treatment with special x-ray pictures. The pictures find and mark the exact area to treat. Then the radiation can go as directly as possible to the tumor, with less effect on normal, healthy tissue.

smoking rate: How many people in a defined group smoke tobacco products. These products include cigarettes, cigars, pipes and any other tobacco or nicotine product. For example, the smoking rate of US men aged 15 and older is the percentage of all US men in that age group who smoke.

social determinants of health: Where a person is born and grows up, and where they live, work, worship and age, shapes their health, how well they function and their quality of life. These conditions are the social determinants of health. Examples: the home and neighborhood, how good the schools are, how much money a person earns, whether transportation is available, health care access and quality, and ties with other people.

social worker: A trained health professional who helps with the social, emotional and environmental problems that illness or disability can bring. Social workers connect people to community resources and support services. They give counseling and guidance on matters such as insurance, moving to a nursing home and emotional distress. An oncology social worker specializes in people with cancer and their families: counseling, money problems, housing, child care (for example, when treatment is far from home) and coping with many kinds of distress.

solar keratosis: See: actinic keratosis.

somatic mutation [so-mat-ick mew-tay-shun]: A DNA change that is not inherited. It appears in a single cell of the body at some point after the embryo forms, and the cells that come from that cell usually carry it too. Sometimes it can lead to cancer. Children do not inherit somatic mutations from their parents.

speech therapist: A health professional with special training to help people who have problems with speech and swallowing. Speech therapists teach skills for communication. They also make sure that patients can eat and drink safely. Also called: speech pathologist, or speech/language pathologist.

s-phase fraction: Of all cells in a sample, the percentage that are busy copying their DNA before they split into 2 new cells. When this number is high, the cancer cells are dividing fast.

sphincter [sfink-ter]: A ring of muscle that opens and closes to control how waste leaves the body. The urethral sphincter closes the urethra tightly and gives bladder control. The anus has 2 of these muscles, the external and internal anal sphincters, which control stool (feces).

spinal cord compression: Pressure on the spinal cord, or on the nerves that branch from it. Cancer that spreads to the spine can cause it. Possible results are pain, numbness or weakness in the legs, and loss of control of urine or stool (incontinence).

spinal tap: See: lumbar puncture (LP).

spindle cell [spin-duhl sell]: A cell that has the shape of a long oval when seen with a microscope. Some types of sarcoma, melanoma and carcinoma have these cells. Some normal cells in the body also have a spindle shape.

spiral CT: A special scanner that makes cross-section pictures of the body in a spiral (helix) pattern. Also called: helical CT.

sputum cytology [spew-tum sy-tahl-uh-jee]: A check of sputum (the mucus you cough up from your lungs) with a microscope, to look for cancer cells.

squamous cell carcinoma [skway-mus sell car-sin-O-mah]: Cancer that begins in squamous cells. These are thin, flat cells, for example in the skin or in the lining of the body's organs.

stage: How large a cancer is, and whether and where it has spread from the primary site. The clinical stage comes from the physical exam, the biopsy and imaging tests. The pathologic stage comes from how the cells in tissue from surgery or a biopsy look with a microscope.

staging: The process to find out how much cancer is in the body and where it is. Different types of cancer use different staging systems. The TNM staging system is the one used most.

standard of care: The treatment or care process that medical experts accept as correct for a disease at a given time.

standard therapy: Treatment that research has shown to be safe and to work for one or more types of cancer, or to help control side effects of treatment. Also called: conventional treatment, or mainstream treatment.

statistical analysis: Methods for exploring and organizing big sets of data so that patterns and trends become clear. American Cancer Society researchers, for example, use these methods to learn which risk factors influence whether a person gets cancer.

stem cells: Immature cells that can become several different types of cells. When people talk about cancer, the term usually means the immature blood cells (hematopoietic stem cells) in the blood and bone marrow, which can become every type of blood cell.

stem cell transplant: See: bone marrow transplant.

stenosis [steh-no-sis]: A narrowing (stricture) of a duct or a canal.

stent: A very small tube, like a straw, that supports and holds open a tube-shaped organ. Examples of these organs are a blood vessel, a bile duct and the intestine.

stereotactic body radiation [steer-e-o-TACK-tick]: The use of stereotactic radiosurgery methods on areas outside the brain, for example the lung, the spine or the liver.

stereotactic needle biopsy [steer-e-o-TACK-tick need-ul by-op-see]: A type of needle biopsy. It is useful when imaging tests show calcifications or a small mass that cannot be felt (for example, in a breast). It is also useful when surgery at the tumor's location is risky (for example, a brain tumor). A computer maps where the mass is and guides where the needle goes.

stereotactic radiosurgery [steer-e-o-TACK-tick ray-dee-o-SUR-jer-ee]: Despite the name, no cutting is involved: it is radiation given from outside the body. Machines concentrate one big, tightly aimed dose on a small target, most often in one visit, so that the tissue around the target is spared as much as possible. It is a treatment for tumors in the brain and elsewhere in the head.

sterility: Not being able to have children. Some types of cancer treatment can cause it. Also called: infertility.

sternum: The breastbone. It is the flat bone at the center front of the chest, where the ribs meet.

stoma [sto-muh]: An opening that surgery makes to connect a body part to the outside of the body. A stoma in the neck can let a person breathe (a tracheostomy, or trach). Other stomas let stool or urine leave the body, for example a colostomy, an ileostomy or a urostomy.

stomatitis [sto-muh-TIE-tus]: Inflammation, sores or ulcers in the mouth. It can be a side effect of some types of chemotherapy, radiation treatment, targeted therapy and immunotherapy. Also called: mucositis.

stool: The solid waste from the bowels that leaves the body through the anus. Also called: feces, or poop.

stool DNA testing: A test that finds abnormal DNA (deoxyribonucleic acid) in stool. The DNA comes from cells that polyps or colorectal cancers in the large intestine shed. This test can help with colorectal cancer screening.

stool softener: A mild laxative that keeps stool from becoming hard and dry, so it is easier to pass. See also: laxative.

stress incontinence: Leaking a small amount of urine during coughing, laughing, sneezing, lifting heavy things or exercise.

stricture [strick-chure]: A narrowing or tightening of a tube, duct or hollow organ, for example the esophagus, a ureter or the urethra.

stroma [stro-muh]: The connective tissue that gives support to the body's organs and other structures.

strontium-89 [stron-tee-um]: A radioisotope (radioactive substance) used against bone pain when cancer has spread to bone. It is given into a vein and is drawn to the parts of bone where the cancer is. There, its radiation kills cancer cells, which helps ease the pain.

superior: Above another part of the body or organ, nearer to the head.

surgeon [sur-jun]: A doctor trained in operations that cut out tumors or remove body parts that a disease has damaged. A surgical oncologist treats cancer with surgery. A thoracic surgeon operates in the chest (thorax), on organs such as the lungs, the ribs, the sternum (breastbone) and the diaphragm, the muscle that helps with breathing.

surgical biopsy: Removing tissue through an incision (an open cut), so that it can be checked with a microscope for cancer cells.

surgical margin: The edge of the tissue that surgery removes. A negative margin means there are no cancer cells on the outer edge of the removed tissue. Doctors take this as a sign that no cancer stayed behind. A positive margin means there are cancer cells on the outer edge, so more surgery can be necessary.

surgical oncologist: A doctor who specializes in surgery to treat cancer.

survival rate: The percentage of people who are alive a given time after diagnosis. For cancer, doctors often give a 5-year survival rate. It does not mean that people cannot live longer than 5 years. It also does not mean that people who live 5 years are cured.

survivor: A person who has ever been diagnosed with cancer, wherever they are in their disease. Someone who is living with cancer now can be a survivor. Some people use the word only after treatment is finished, and others only after several years have passed since diagnosis. The American Cancer Society believes every person may define their own cancer experience. It counts as a survivor anyone who calls themselves one, from the day of diagnosis for the rest of their life.

survivorship: Being a cancer survivor, that is, having had a cancer diagnosis.

symptom [simp-tuhm]: A change in the body that the person who has it notices, for example pain or fatigue. Compare to: sign.

synchronous [sin-kruh-nus]: Present or occurring at the same time. For example, a person can be found to have two or more primary cancers at once. They can be the same type of cancer in separate tumors (for example, in both breasts), or different types (for example, bladder cancer and lung cancer).

synergistic [sin-er-JIS-tick]: Working together. A synergistic agent works with one or more other agents to make an effect larger than the sum of their separate effects. Some chemotherapy drugs work synergistically.

systemic disease [sis-tem-ick]: In cancer, a cancer that began in one place and has spread to distant organs or structures.

systemic radiation therapy [sis-tem-ick]: Radiation therapy where a person swallows a radioactive substance, or gets it by injection. The substance finds and kills cancer cells. Examples are radioactive iodine and a monoclonal antibody with a radioactive label.

systemic therapy [sis-tem-ick]: Treatment that reaches cells everywhere in the body and affects them. Examples are chemotherapy, hormone therapy, targeted therapy and immunotherapy.

T

targeted therapy: Treatment with drugs or other substances that find and attack specific cancer cells. These therapies usually affect normal cells less than other cancer treatments do, so they usually cause fewer side effects.

T cells: White blood cells (immune cells) that do much of the immune system's work against things it sees as foreign: viruses, transplanted organs and tissue, and cancer cells. A T cell identifies the foreign thing and sends out chemical signals (cytokines). These signals get other parts of the immune system to destroy it. Also called: T lymphocytes.

temporary brachytherapy: See: high-dose rate (HDR) or temporary brachytherapy.

terminal illness [ter-min-uhl]: An illness that has no cure and that doctors expect will cause the person's death.

testosterone [tes-toss-ter-own]: The main male hormone, produced chiefly in the testicles. Libido (sex drive), making sperm, the growth of certain tissues and secondary sex traits all depend on it. Prostate cancer can grow faster because of it.

therapy: Any of the steps taken to treat a disease. Also called: treatment.

thermography [thur-mog-ruh-fee]: A test that records breast temperature as a heat map. The FDA warns against using it as a substitute for mammograms, whether to screen for or to diagnose breast cancer. No sound study has found it to be a useful screening test for any condition.

thoracic surgeon [thuh-ras-ick sur-jun]: A surgeon for the organs inside the chest cavity. The word thoracic comes from thorax, another word for chest.

three-dimensional conformal radiation therapy (3D-CRT): Radiation treatment planned with advanced computers that map the cancer's position in the body very exactly. The patient can be fitted with a plastic mold, similar to a cast, so that they stay still and in the same position every time. Aiming is then more exact, normal tissue gets less radiation, and doctors may be able to give higher doses. Also called: 3D-CRT.

thriver: A person who uses their cancer experience as a chance for personal growth. This person focuses on quality of life and on living as well as possible.

thrombocytopenia [throm-bo-sy-toe-PEEN-ee-uh]: Too few platelets in the blood. Chemotherapy and radiation therapy can cause it as a side effect. It can make bruising and bleeding more likely.

tissue [tish-oo]: A group of cells that work together to do a specific job.

TNM staging system: The system used most to stage cancers. It uses 3 key pieces of information:

• T: the size of the tumor.
• N: whether the cancer has spread to nearby lymph nodes, and to how many.
• M: whether the cancer has spread (metastasized) to other organs.

Letters or numbers after T, N and M give more detail about each one. To make this easier to understand, the TNM results can be combined into a simpler set of stages, with Roman numerals (usually I to IV). In general, a lower number means the cancer has spread less. A higher number means a more serious cancer. Also called: AJCC staging system.

total androgen blockade: See: combined androgen blockade (CAB).

toxic [tock-sick]: Harmful or poisonous. It usually causes more severe side effects.

transfusion [trans-few-zhun]: Giving blood or blood products through a vein (intravenous, or IV). Most of these products come from donors who are not related to the patient, and they are tested for disease first. Before some planned surgeries or procedures, a person can donate their own blood so that it is ready for them.

translocation [tranz-low-KAY-shun]: A piece of a chromosome that has broken off and become attached to another chromosome, so the DNA sits in the wrong place. This kind of change may play a part in leukemia, breast cancer, Down syndrome, muscular dystrophy and schizophrenia.

tumor [too-mer]: An abnormal growth of tissue. A tumor can be benign (not cancer) or malignant (cancer).

tumor flare: Symptoms or tumor markers that get worse for a short time after treatment starts.

tumor markers: See: biomarkers.

tumor necrosis factor (TNF) [too-mer neck-row-sis]: A substance that activated white blood cells release. It can cause tumor cells to die.

tumor suppressor genes: Genes that slow cell division, repair mistakes in DNA, or make cells die at the correct time. Changes (mutations) in these genes can cause too much cell growth, which can lead to cancer.

tumor volume: A measure of how much cancer is present.

U

ulcerative colitis [ul-suh-ruh-tiv kuh-lie-tis]: A type of inflammatory bowel disease where the colon is inflamed for a long time. It increases the risk of colon cancer. For this reason, doctors recommend that colorectal cancer screening start earlier and happen more often.

ultrasound or ultrasonography [ul-truh-sound or ul-truh-son-AH-gruf-ee]: An imaging test that uses high-frequency sound waves. It shows the structure and movement of body organs and the flow through blood vessels. The sound waves make echoes, and a computer shows these echoes on a screen.

umbilical cord blood transplant: The use of stem cells from the umbilical cord blood of newborn babies. These cells replace the blood-forming stem cells of a patient whose own stem cells radiation or chemotherapy destroyed.

unilateral [yoo-nih-LAT-uh-ruhl]: On one side of the body only. Unilateral breast cancer, for example, is in a single breast. Compare to: bilateral.

urge incontinence: A sudden urge to urinate that a person cannot control, even when the bladder is not full. A bladder infection or irritation from radiation therapy can cause it. Also called: overactive bladder.

urinary frequency: Needing to urinate (pass urine) often.

urinary incontinence: Losing some or all control of urination.

urinary retention: Not being able to empty the bladder, or not being able to urinate.

urinary urgency: Feeling that you must urinate (pass urine) immediately.

urinate [YUR-uh-nate]: To pass urine from the bladder out of the body.

urine cytology [yur-in sy-tahl-uh-jee]: Tests on a urine sample that look for cancer or pre-cancer cells. The tests can also use bladder washings. For bladder washings, a salt solution goes into the bladder through a tube (a catheter), and then the solution comes out for testing.

urodynamic study [yur-o-die-NAM-ick]: A check of how well the bladder muscle and the sphincters work.

urologist [yur-ahl-uh-jist]: A doctor who specializes in problems of the urinary tract (in all sexes) and of the male reproductive tract.

uterine fibroid tumor [yew-ter-in fi-broyd too-mer or tyoo-mer]: A noncancerous growth of fibrous or connective tissue, and the most common tumor in women. It can grow in the wall of the uterus or push into its lining. Most cause no symptoms. Depending on how big it is and where it is, it can cause abnormal bleeding or other symptoms. Also called: fibroma.

V

vaccine [vack-seen]: A substance that trains the immune system to resist or treat one specific infection or disease. Some vaccines prevent infections, such as human papillomavirus (HPV). Others help the body fight one specific type of cancer.

vaginal dryness and atrophy [va-juh-nuhl drai-nuhs and a-truh-fee]: The vagina loses moisture, and its walls can no longer stretch and move comfortably. This usually happens after menopause, or when cancer treatment decreases estrogen. It can make intercourse difficult and sometimes painful.

vaginal stenosis [va-juh-nuhl steh-no-sis]: The vagina becomes shorter or narrower because scar tissue forms after surgery or radiation treatment.

vascular endothelial growth factor (VEGF) [vas-ku-lur en-doe-THEE-lee-uhl]: A protein that helps tumors make new blood vessels, which bring the nutrients the tumors need to grow.

ventral: At or near the front of the body.

virtual colonoscopy: A way to look for polyps or masses in the colon and rectum without a scope. A CT scan uses x-rays, and software builds 3-dimensional views of the inside of the colon and rectum from them.

virus [vy-rus]: A tiny micro-organism that causes infections. Some viruses also raise the risk of certain cancers, for example human papillomavirus (HPV) and cervical cancer.

W

watchful waiting: See: active surveillance.

white blood cells (WBCs): Blood cells that help the body fight infections. There are many types. Some cancer treatments, such as chemotherapy, can decrease the number of these cells, which makes infections more likely.

wire localization [lo-cull-ih-ZAY-shun]: A way to guide a surgeon to a lump that is hard to find, or to a suspicious spot seen on an x-ray, during a surgical biopsy. Using x-ray images, the doctor places a thin hollow needle at the spot. A fine wire is passed through it, and a tiny hook on the wire tip anchors it. Then the needle is withdrawn and only the wire is left. The surgeon traces the wire to locate and take out the abnormal tissue.

X

x-ray: A form of radiation. At low levels it makes pictures of the inside of the body. At high levels it kills cancer cells.

Source: https://www.cancer.org/cancer/understanding-cancer/glossary.html