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Cancer Glossary

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Browse the glossary by selecting a letter or by entering a cancer-related term:

A tumor marker sometimes found in the blood of people with colorectal, stomach, bile duct, and pancreatic cancers. It may also be found in some non-cancer conditions. See also tumor markers.
Combined androgen blockade. See combination hormone therapy.
 Search  [ka-KEK-see-uh]
A profound state of general poor health and malnutrition (poor food intake and/or poor food absorption) that leads to loss of body weight and muscle mass.
 Search  [KALS-if-ik-A-shuns]
Tiny calcium deposits in the body. For example, they may be seen on a mammogram of the the breast, where they may be alone or in clusters. Very small deposits may be called microcalcifications. They are a sign of changes within the breast that may need to be followed by more mammograms or a biopsy. See also biopsy, mammogram.
A group of diseases which cause cells in the body to change and grow out of control. Most types of cancer cells form a lump or mass called a tumor. (Not all tumors are cancer. A tumor that is not cancer is called benign, while a cancerous tumor is called malignant.) A cancerous tumor can invade and destroy healthy tissue. Cells from the cancer can break away and travel to other parts of the body. There they can continue to grow. This spreading process is called metastasis. When cancer spreads, it is still named after the part of the body where it started. (For example, if colon cancer spreads to the liver, it’s still colon cancer, not liver cancer.) Benign tumors do not grow and spread the way cancer does. They are usually not a threat to life. Note that some types of cancer, such as blood cancers, do not form tumors. They can still threaten life by crowding out normal cells. See also benign, malignant, metastasis, tumor.
The group of health care professionals who work together to find, treat, and care for people with cancer. The cancer care team may include any or all of the specialists listed. Whether the team is linked formally or informally, there’s usually one person who takes the job of coordinating the team. See also medical oncologist, radiation oncologist, pathologist, oncology clinical nurse specialist, oncology social worker, neurosurgeon, surgeon, gynecologist, gynecologic oncologist, urologist.
A cell that divides and reproduces abnormally and can spread throughout the body, crowding out normal cells and tissue. Cancer cells develop because of damage to their DNA (deoxyribonucleic acid). See also cancer, deoxyribonucleic acid, mutation.
See screening.
Genes (the basic unit of heredity) inherited from one’s parents that greatly increase the risk of a person developing cancer. About 5% to 10% of all cancers are caused by these genes. See also gene.
A vaccine used to help the immune system fight cancer cells. Most vaccines in use or in development expose the immune system to parts of cancer cells as a way of trying to treat cancer, not prevent it. However, some vaccines already in use reduce cancer risk indirectly, by helping the body fight cancer-causing viruses such as the human papilloma virus (HPV) and the hepatitis B virus. See also human papilloma virus.
A routine health exam for cancer in people without signs or symptoms of cancer. The goal of the cancer-related check-up is to find the disease, if it exists, at an early stage, when chances for cure are greatest. See also detection, screening.
An unusual and ongoing tiredness that can occur with cancer or cancer treatments. It can be overwhelming, last a long time, and interfere with everyday life. Rest does not always relieve it.
A narrow tube-like device. Different kinds may be used to hold tissues open during laparoscopy, or to give IV medicines and fluids. See also intravenous (IV), laparoscopy.
Scar tissue that may form around an implant as the body reacts to the foreign object.
 Search  [CAR-sin-o-EM-bre-ON-ic AN-tuh-jin]
Often shortened to CEA. A substance normally found in certain fetal tissues. If found in the blood of an adult, it may suggest that a cancer, especially one starting in the digestive system, may be present. Blood tests for this substance may help doctors find out if a colorectal cancer has come back after treatment. The test is not helpful for screening for colorectal cancer because of the large number of false positives and false negatives. See also digestive system, false negative, false positive, screening, tumor marker, colorectal cancer.
 Search  [car-SIN-o-jin]
Any substance that causes cancer or helps cancer grow.
 Search  [CAR-sin-oyd SIN-drom]
A group of symptoms produced by cancer cells that release large amounts of hormones, which cause facial flushing, wheezing, diarrhea, a fast heartbeat, and other symptoms. See also carcinoid tumors, hormone.
 Search  [CAR-sin-oyd]
Also called carcinoids. Tumors that develop from nerve and endocrine (neuroendocrine) cells, usually in the digestive tract or lung. The cells from these tumors release certain hormones into the bloodstream. In a small percentage of people, the hormone levels get high enough to cause facial flushing, wheezing, diarrhea, a fast heartbeat, and other symptoms. See also carcinoid syndrome, endocrine glands, hormone.
 Search  [CAR-sin-O-ma]
A cancer that begins in the lining layer (epithelial cells) of organs. Most cancers are carcinomas.
 Search  [CAR-sin-O-ma in SY-too]
An early stage of cancer in which the cancer cells are only in the layer of cells where they first began, and have not grown into nearby tissues in other parts of the organ or spread to distant parts of the body. Compare to invasive cancer. See also carcinoma.
The member of a cancer care team, usually a nurse or oncology nurse specialist, who coordinates the patient’s care throughout diagnosis, treatment, and recovery. The case manager acts as a guide through the complex system of health care by getting responses to questions, managing crises, and connecting the patient and family to people or groups that can offer needed help. See also cancer care team.
An overgrowth of lymph nodes and other lymphoid tissues (found in the thymus, spleen, tonsils, bone marrow, digestive tract, and other organs). It’s not a type of cancer, but sometimes it can act very much like lymphoma, and even develop into lymphoma. See also lymph node, lymphoma, thymus, spleen.
Prostate cancer that’s still growing even when the testosterone levels are as low as what would be expected if the testicles were removed (called “castrate” levels). Some of these cancers may still be helped by other forms of hormone therapy. Compare to androgen-independent. See also hormone therapy, testicles, testosterone.
 Search  [cass-TRAY-shun]
Surgery to remove the testicles; the medical term is orchiectomy. See also androgen deprivation therapy, chemical castration, testicles.
 Search  [CATH-it-ur]
A thin, flexible tube through which fluids enter or leave the body; for example, a tube to drain urine is called a Foley catheter. See also urine.
 Search  [KAW-zul]
A relationship in which one factor is thought to be responsible for or cause an outcome; for instance, smoking has a causal link to lung cancer.
See complete blood count.
A gene that makes a protein called epithelial cadherin. A change (mutation) in this gene can cause hereditary diffuse gastric cancer (a rare type of stomach cancer) to develop at an early age. Women who inherit changes in this gene also have a higher risk of lobular breast cancer. See also inherited disease, lobular carcinoma in situ, mutation.
See carcinoembryonic antigen.
 Search  [SEE-kum]
A pouch at the start of the colon, where the small intestine empties into the large intestine. See also colon, gastrointestinal tract.
The basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (in a process called mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer. See also cancer.
The series of steps that a cell must go through to divide; some cancer treatments work by interfering with the cell cycle.
 Search  [CENT-uh-gray]
A unit for measuring radiation transfer. See also radiation dose.
 Search  [SEN-tuh-ME-ter]
Also written as cm. Metric measure of length, 1/100 of a meter. 2½ cm = 1 inch. See also meter, millimeter.
Often shortened to CNS. The brain and spinal cord, which serve as the main “processing center” for the entire nervous system. See also nerve, nervous system, peripheral nervous system.
 Search  [suh-REE-bro-SPY-nuhl]
Often shortened to CSF. A special clear liquid that surrounds and cushions the brain and spinal cord. See also brain, spinal cord.
 Search  [SER-vih-kul]
cancer that starts in the cells lining the cervix – the lower part of the uterus (womb) that connects the uterus to the vagina. See also cervix, uterus, vagina.
 Search  [SER-vix]
The lower part, or neck, of the womb (uterus), which connects the uterus to the vagina. See also uterus, vagina.
Centigray; a unit for measuring radiation transfer. See gray under radiation dose.
A gene that, if damaged or mutated, can increase the risk of breast and other types of cancer. This damaged gene can be inherited. See also gene, inherited disease, mutation.
 Search  [KEM-ih-kul cast-RAY-shun]
The use of hormone therapy drugs to achieve very low levels of testosterone without surgical removal of the testicles. See also androgen deprivation therapy, castration, castrate-resistant, testicles.
 Search  [KEY-mo BRAIN]
Also written chemobrain or chemo-brain; also called chemo fog. The mental cloudiness people with cancer sometimes notice before, during, and after chemotherapy. Despite the name, researchers are finding other factors that also seem to be linked to this problem.
 Search  [KEY-mo-pre-VEN-shun]
The use of drugs, chemicals, or other substances to help keep cancer from developing or coming back.
 Search  [KEY-mo-THAIR-uh-pee]
Treatment with drugs that kill cancer cells. Often called chemo.
 Search  [kor-EE-oh-CAR-sin-O-ma]
Cancer that starts in the cells that would normally develop into a placenta inside the womb (uterus) during pregnancy. Compare to gestational trophoblastic disease.
 Search  [KRO-mo-JEN-ick in SY-too HI-brid-ih-ZA-shun]
Often shortened to CISH. a lab test that uses small DNA (deoxyribonucleic acid) probes to count certain genes in cancer cells. See also deoxyribonucleic acid, gene.
 Search  [KRO-muh-SOAM]
A strand of DNA (deoxyribonucleic acid) inside a cell that carries genes, the basic units of heredity. Humans have 23 pairs of chromosomes, one member of each pair from the mother, the other from the father. Each chromosome can contain hundreds or thousands of individual genes. See also deoxyribonucleic acid, gene, ploidy.
 Search  [KRON-ick in-FLAM-uh-TOR-ee]
See inflammatory bowel disease.
 Search  [KRON-ick ob-STRUK-tiv PULL-muh-NERR-ee]
Often shortened to COPD. Lung disease such as emphysema or chronic bronchitis, which harms the lungs and makes it harder to breathe. Often caused by smoking; sometimes caused by other exposures and illnesses.
 Search  [kime]
The thick, nearly liquid mixture of partly digested food and digestive juices found in the stomach and small intestine.
A tool used to help health professionals estimate a woman’s breast cancer risk based on family history.
 Search  [KLAV-ih-kuhl]
The collarbone. One on either side connects bones of the shoulder to the breastbone (sternum). Lymph nodes are above and below this bone. See also lymph node, infraclavicular, supraclavicular.
Often shortened to CBE. Examination of the breasts done by a health professional such as a doctor or nurse to check for lumps or other changes. Clinical breast exam is no longer recommended for breast cancer screening.
See staging.
Research studies that use human volunteers, usually to test new drugs or other treatments to compare current, standard treatments with others that may be better. They may also test new ways to diagnose or prevent a disease. Before a new treatment or test is used on people, it is studied in the lab. If lab studies suggest it will work, the next step is to test it in patients.
 Search  [KLIT-or-is]
A small cylinder of erectile tissue at the front of a woman’s genitals, just inside the inner lips (labia minora). See also labia, vulva.
 Search  [kuh-LEK-tuh-me]
Surgery that removes all (total colectomy) or part (partial colectomy or hemicolectomy) of the colon. See also colon.
 Search  [kuh-LIE-tis]
A general term for inflammation of the large intestine (colon). Colitis can be intermittent (it comes and goes) or chronic (long-lasting, as in ulcerative colitis). See also colon, inflammatory bowel disease.
 Search  [KO-lo-A-nuhl uh-NAS-tuh-MO-sis]
Surgery in which the rectum is removed and the colon is attached to the anus. Sometimes a small pouch is made to take the place of the rectum, by doubling back a short segment of colon (colonic J-pouch) or enlarging a segment (coloplasty). A temporary colostomy is needed while the pouch heals. See also anus, colon, colostomy, low anterior resection, rectum.
 Search  [KO-lun]
The major part of the large intestine. The colon is a muscular tube about 5 feet long. It’s divided into 4 sections, starting with the ascending, transverse, descending, and ending with the sigmoid colon. It continues the process of absorbing water and mineral nutrients from food that was started in the small intestine. The cecum and the rectum mark the beginning and end of the colon, though they are not actually part of it. See also cecum, rectum.
 Search  [ko-LAHN-uh-SCOPE]
A thin, flexible, hollow, lighted tube about the thickness of a finger with a small video camera on the end. It’s put in through the rectum and moved up into the colon to look closely at the inside of the entire colon. Compare to sigmoidoscope. See also colon, colonoscopy, rectum.
 Search  [KO-lun-AH-skuh-pee]
A procedure in which a doctor uses a colonoscope to see inside the colon to look for polyps or cancer. See also colon, colonoscope, colorectal cancer screening, colonoscopy preparation.
 Search  [KO-lun-AH-skuh-pee]
Also called colonoscopy prep. The use of a liquid diet along with laxatives (and sometimes enemas) to clean out the entire colon before the colonoscopy or virtual colonoscopy is done. This preparation is usually started 1 or 2 days before the colonoscopy. See also colon, colonoscopy, laxative, virtual colonoscopy.
Often shortened to CSFs. Types of growth factors that promote growth and division of blood-producing cells in the bone marrow. CSFs are naturally produced in the body. Man-made versions of CSFs may be given to reduce or prevent certain side effects of chemotherapy that may be caused by not having enough blood cells. They may also be given before harvesting stem cells from a donor for stem cell transplant. See also bone marrow, chemotherapy, hematopoietic stem cell transplant, stem cells.
A type of ultrasound that uses a computer to convert sounds into colors to represent blood flow within an organ. It may be used to help find some cancers, since tumors often have more blood flow than normal tissue. See also transrectal ultrasound, ultrasound.
 Search  [KO-lo-REK-tuhl]
Often shortened to CRC. Cancer that starts in the colon or rectum. Since colon cancer and rectal cancer have many features in common they are often referred to together as colorectal cancer. See also colon, rectum.
 Search  [KO-lo-REK-tuhl]
Testing to look for abnormalities in the colon or rectum early, before signs and symptoms start. This can often find cancer earlier, when it’s most curable. Some types of screening allow doctors to find and remove polyps, which can even prevent cancer from developing. See also screening, polyp.
 Search  [kuh-LAHS-tuh-me]
An opening created by surgery that attaches the colon to the skin on the belly (abdomen) to make a new path to get rid of solid body waste (poop or stool). A small pouch is placed at the opening to collect the stool. See also colon, rectum.
 Search  [kol-PA-skuh-pee]
A close examination of the inside of the vagina and the lower part of the womb (cervix) using a colposcope, a lighted magnifying device. See also cervix, vagina.
Use of multiple ways to affect the body’s hormone levels. For example, prostate cancer is sometimes treated by using castration or an LHRH analog to lower testosterone levels, plus an anti-androgen to help block the cancer cells from using any remaining male hormones (androgens). This is also called combined androgen blockade (CAB), total hormonal ablation, total androgen blockade, or total androgen ablation. See also androgens, androgen deprivation therapy, castration, hormone therapy, luteinizing hormone-releasing hormone analogs, testosterone.
Often shortened to CAB. See combination hormone therapy.
 Search  [mo-DAL-ih-tee]
Using 2 or more types of treatment sequentially or together to get the best results. For example, surgery for cancer is often followed by chemotherapy to kill any cancer cells that may still be in the body. See also adjuvant therapy, neoadjuvant therapy, chemotherapy.
 Search  [KOM-id-o-CAR-sin-NO-muh]
A type of breast cancer called ductal carcinoma in situ that has dead or dying cancer cells in the center of the ducts. See also ductal carcinoma in situ.
A non-standard treatment (often self-prescribed) used along with standard medical treatment. Some complementary therapies may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient’s sense of well-being. These can include herbs, meditation, massage or touch, and many other types of treatments. The ACS recommends that patients thinking about using any alternative or complementary therapy discuss it first with a member of their health care team, since many of these treatments are unproven and some can be harmful. Compare with alternative therapy.
Often shortened to CBC. A count of the number of cells in a given sample of blood. Red blood cells, white blood cells, and platelets are most often counted for this lab test. See also platelets, red blood cells, white blood cells.
 Search  [toe-MAHG-ruh-fee]
Also called a CT scan or CAT scan. An imaging test in which many x-rays are taken from different angles of a part of the body. These images are combined by a computer to make cross-sectional pictures that show details of internal organs much better than standard x-rays. Except for when the dye is injected (needed in some but not all cases), this is a painless test that can be done in an outpatient clinic. See also imaging tests, ionizing radiation.
Often shortened to CAD. A process in which a radiologist uses a computer program to help interpret a mammogram or other imaging test. See also imaging tests, mammogram.
Treatment or therapy given at the same time as another treatment.
Chemotherapy and/or radiation therapy used to destroy the bone marrow or reduce its function in order to prepare for a stem cell transplant. See also hematopoietic stem cell transplant, myeloablative treatment, reduced-intensity conditioning.
A technique for giving radiation therapy that uses proton beams rather than standard radiation. (Protons are parts of atoms.) Unlike standard radiation beams, which release energy both before and after hitting the target, proton beams cause less damage to tissues they pass through, and then release their energy after traveling a certain distance. Proton beam therapy has not been directly compared to standard radiation methods, but the hope is that it may be able to deliver more radiation to the cancer with less damage to nearby normal tissues. It’s still fairly new and is offered in only a small number of treatment centers. See also conformal radiation therapy, external beam radiation therapy, ionizing radiation.
A type of radiation treatment that uses a special computer to help shape the beams of radiation to match the shape of the tumor. It also delivers the beams from several different directions rather than all going in from one angle. This cuts down the amount of exposure that any one section of healthy tissue gets by spreading out the entry points. See also external beam radiation therapy, ionizing radiation, photon beam radiation therapy.
In research or clinical trials, the group that does not get the treatment being tested. In cancer research, this group most often gets standard treatment (which has already been tested and is in general use). If no standard treatment exists, the control group may get a placebo or sham treatment. Sometimes called the comparison group. See also clinical trials, placebo.
See standard therapy.
See chronic obstructive pulmonary disease.
See umbilical cord blood transplant.
A procedure in which a wide, hollow needle is used to take out pieces of tissue to look for cancer or other diseases. See also biopsy, biopsy gun.
 Search  [KOR-tih-ko-STAIR-oyd]
Any of a number of steroid hormones made by the outer layer (cortex) of the adrenal glands. Man-made versions are sometimes used as cancer treatments or to help with symptoms or side effects. See also adrenal glands.
 Search  [CRAY-nee-um]
The part of the skull bones that enclose and protect the brain, and support the structures of the face. See also brain.
 Search  [kronz]
A type of chronic inflammatory bowel disease where the small intestine or, less often, the colon is inflamed over a long period of time. This increases a person’s risk of developing colon cancer. See also colon, inflammatory bowel disease, small intestine.
 Search  [CRY-o-ah-BLAY-shun]
Use of extreme cold to freeze and kill cancer cells.
 Search  [CRY-o-SUR-juh-ree]
See cryoablation.
See virtual colonoscopy.
See computed tomography.
A procedure that uses special x-rays to show a tumor while the doctor advances a biopsy needle toward it. The images are repeated until the doctor is sure the needle is in the tumor or mass. A piece of the tumor is then taken out, usually through the needle, and looked at under the microscope. See also biopsy.
 Search  [KUR-uh-tiv]
Treatment aimed at producing a cure. Compare with palliative treatment.
 Search  [cue-TAY-nee-us]
Having to do with the skin.
 Search  [sist]
A fluid-filled mass that’s usually not cancer.
 Search  [SIS-tuh-SKOP]
A thin, flexible tube with a lens and a light on the end. It’s put into the bladder through the urethra, allowing the doctor to see the insides of these organs. See also bladder, cystoscopy, urethra.
 Search  [sis-TAH-skuh-pee]
A procedure that looks at the inside of the urethra and bladder with a thin, flexible, lighted tube called a cystoscope. See also bladder, cystoscope, urethra.
 Search  [SY-toe-juh-NET-icks]
Tests that look for abnormal changes (mutations) in whole chromosomes. Also called chromosome analysis. It’s often done on bone marrow samples in patients with certain types of cancer, such as leukemia or lymphoma. See also bone marrow, chromosome, mutation, genetic testing.
 Search  [SY-toe-kine]
A substance that’s made by cells of the body’s immune system that can affect the immune response. Cytokines can also be made in the lab and given to people to help the body fight cancer, infection, and other diseases. See also immune system.
 Search  [sy-TAHL-uh-jee]
The branch of science that deals with the structure and function of cells. Also refers to tests to diagnose cancer and other diseases by looking at cells under the microscope. See also cell.
 Search  [sy-TAHM-uh-tree]
The counting and measuring of cells using a machine called a flow cytometer. See also cell.
 Search  [SY-toe-PEE-nee-uh]
A lower-than-normal number of blood cells. See also complete blood count, platelets, red blood cells, white blood cells.
 Search  [SY-toe-TOK-sick]
Toxic to cells; cell-killing. See also cell.