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Cancer Glossary

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

 Search  [SAY-lean]
Saltwater solution.
 Search  [SAL-ih-vair-ee]
Glands that produce spit (saliva) in the mouth to keep it soft and moist and help start the digestion of food.
 Search  [sar-KO-muh]
A cancer that starts in connective tissue, such as cartilage, fat, muscle, or bone.
A test that uses x-rays, magnets, sound waves, or radioisotopes to make pictures of the inside of the body. See also imaging tests, bone scan, brain scan, computed tomography scan, magnetic resonance imaging, nuclear medicine scan, radioisotope, x-ray.
 Search  [SIN-till-LAY-shun]
Device used in nuclear medicine scans to detect radioactivity and make pictures that help diagnose cancer and other diseases. See also nuclear medicine, nuclear medicine scan.
 Search  [SIN-ti-mam-AHG-gruh-fee]
Also called breast specific gamma imaging (BSGI) or molecular breast imaging (MBI). An imaging test in which a radioactive tracer is put into the blood through a vein to help find breast cancer. The tracer collects in the breasts, and different patterns can show “hot spots” or areas of greater activity. This test may help evaluate women with abnormal mammograms, and is still being studied as doctors try to improve its usefulness. See also imaging tests, mammogram, nuclear medicine scan, radioisotope.
The search for disease, such as cancer, in people who do not have any signs or symptoms. For example, screening tests for colon cancer include colonoscopy and the fecal occult blood test. Some of the same tests used for screening may also be used as diagnostic tests, which look for cancer in a person after there’s some sign of a problem. For instance, a colonoscopy would be a diagnostic test if it was used in a person who had blood in the poop (stool) or symptoms of a blockage. See also colon, colonoscopy, fecal occult blood test, sign, symptom.
The pouch of skin that holds the testicles. See also testicles.
A tumor that forms as a result of spread (metastasis) of cancer from the place where it started (the primary site). See also metastasis, primary site.
 Search  [suh-DAY-shun]
The state of being sleepy, calm, or relaxed, or the use of drugs to cause such an effect. Sedation is often used along with medicines to numb an area for a procedure or certain types of surgery. See also anesthesia.
 Search  [seg-MEN-tuhl re-SEK-shun]
Surgery to remove part of an organ. With colon cancer, for instance, the cancer and a length of normal colon on either side of the cancer, as well as the nearby lymph nodes are removed. The remaining sections of the colon are then attached to each other. See also colon, lymph node.
Often shortened to SERM. An estrogen-like drug that has some, but not all, of the actions of estrogen. For example, the drug raloxifene is classified as a SERM because it acts like estrogen in some parts of the body (for example, helping prevent bone loss) but blocks the effects of estrogen in others (for instance, it helps stop breast cells from using estrogen). See also estrogen, uterus.
 Search  [SEE-muhn]
Fluid released during male orgasm that contains sperm and seminal fluid. See also ejaculate, sperm.
 Search  [SIM-uh-nul VES-ih-kuls]
Glands in men at the base of the bladder and next to the prostate that release fluid and sperm into the semen during orgasm. See also bladder, prostate, semen.
 Search  [SEN-tin-uhl]
Often shortened to SLNB. A procedure that’s used instead of routine removal (dissection) of lymph nodes for some cancer types to look for cancer spread to nearby lymph nodes. Blue dye and/or a radioisotope is injected into or near the tumor during surgery, and the first (sentinel) node that picks up the dye is removed and checked for cancer cells. If the node does not contain cancer, other nodes probably do not need to be removed. See also biopsy, lymph node, lymph node dissection, radioisotope.
A lump or swelling that’s caused by a build-up of clear fluid and is not cancer.
A mental health professional such as a licensed psychiatrist, social worker, clinical nurse specialist, nurse practitioner, or psychologist with special training in counseling people about sexual changes, problems, and communication.
Unwanted effects of treatment such as hair loss caused by chemotherapy or extreme tiredness (fatigue) caused by radiation therapy. See also chemotherapy, radiation therapy.
Often written as Sv. See radiation dose.
 Search  [SIG-moyd KO-lun]
The fourth and last section of the colon. The sigmoid colon attaches to the rectum, where waste matter is stored until it leaves the body through the anus. See also anus, ascending colon, colon, descending colon, transverse colon, rectum.
 Search  [sig-MOYD-uh-SCOPE]
Also called a flexible sigmoidoscope. 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 advanced into the lower part of the colon. The sigmoidoscope is connected to a monitor so the doctor can look at the inside of the rectum and the lower part of the colon for cancer or for small growths that can become cancer (polyps). See also colon, polyp, rectum, sigmoid colon, sigmoidoscopy.
 Search  [SIG-moid-AH-skuh-pee]
A procedure in which a doctor uses a thin, flexible tube to look into the rectum and the last part of the colon to check for polyps or other abnormalities. See also colon, polyp, rectum, sigmoid colon, sigmoidoscope.
A physical change that can be seen, felt, or measured in some way. Compare to symptom.
A process involving special imaging tests that are used to plan external beam radiation cancer treatment so that the area to be treated is precisely located and marked. See also external beam radiation therapy.
See spectral karyotyping.
One of the 2 main types of lung cancer grouped based on how the cells look under the microscope. Small cell lung cancer tends to grow and spread faster than the other type, non-small cell lung cancer. Compare to non-small-cell lung cancer.
The longest section of the intestinal tube. It breaks down food and absorbs most of the nutrients. The small intestine starts at the end of the stomach and leads into the large intestine. See also gastrointestinal tract, large intestine, stomach.
A health professional who helps people find community resources and support services, and provides counseling and guidance to help with issues like insurance coverage and nursing home placement. See also cancer care team.
See actinic keratosis.
 Search  [so-MAT-ick mew-TAY-shun]
A change (mutation) in DNA (deoxyribonucleic acid) that starts in one cell of the body at any time of life after an embryo is formed. All the cells that come from that cell will typically have the same mutation, which in some cases can lead to cancer. This kind of mutation is different from an inherited mutation, which is present at birth and found in all the cells of the body. Somatic mutations are not passed on to children. Compare to inherited disease. See also deoxyribonucleic acid, embryo, mutation.
 Search  [SPECK-truhl KAIR-ee-o-TYPE-ing]
Often shortened to SKY; also called chromosome painting. A cytogenetic test that uses different colors to see all the pairs of chromosomes in a cell. See also chromosome, cytogenetics.
Also called a speech pathologist (path-AHL-uh-jist). A health professional who is specially trained to work with people who have speech and swallowing problems. Speech therapists help people learn skills to communicate and also make sure that patients can eat and drink.
The mature male reproductive cell that must combine with an egg (ovum) to make a baby. Males start making sperm in their testicles after they go through puberty. See also ova.
The percentage of cells that are making a copy of their DNA (deoxyribonucleic acid) or replicating. DNA replication usually means that a cell is getting ready to split into 2 new cells. A low s-phase fraction is a sign that a tumor is slow-growing; a high s-phase fraction shows that the cells are dividing rapidly and the tumor is growing quickly. See also deoxyribonucleic acid.
 Search  [SFINK-ter]
A ring-like muscle that can open and close to control the passage of substances in the body. For example, the urethral sphincter squeezes the urethra shut and allows the control of urine. Two of these muscles in the anus, the external and internal anal sphincters, control when poop (stool) leaves the body. See also anus, urethra, urine.
A long bundle of nerves that a makes up part of the central vervous system. It runs up the back enclosed inside the bones of the spine (the vertebrae) and connects to the brain. It carries sensory information from the body to the brain and motor information (signals to move body parts) from the brain to the body. See also brain, central nervous system, peripheral nervous system, vertebra.
Any process that results in pressure on the spinal cord, the spinal nerve trunks, or both. Pressure on the spinal cord can cause numbness, loss of the ability to move (paralysis), or loss of control (incontinence) of poop (stool) or urine. This can happen when cancer spreads to the spine. See also paralysis, spinal cord, urine.
See lumbar puncture.
 Search  [SPIN-duhl sell]
A cell that, when seen under a microscope, looks like a long oval. Some types of sarcomas, melanomas, and carcinomas have this type of cell. There are also normal cells of the body that are spindle shaped. See also carcinoma, melanoma, sarcoma.
Also called helical CT. The most common type of CT (computed tomography) scan. The scanner moves around the body quickly in a spiral or helix pattern as it uses x-rays to make detailed cross-sectional pictures. See also computed tomography scan.
Organ of the immune system in the upper left side of the belly (abdomen) which stores blood, breaks down old blood cells, and helps form some white blood cells such as lymphocytes. See also immune system, lymphocyte.
 Search  [SPEW-tum sy-TAHL-uh-jee]
A study of mucus or phlegm cells under a microscope to see if they are normal.
 Search  [SKWAY-mus sell CAR-sin-O-mah]
Cancer that begins in the flat, non-glandular cells of the body, for example, the skin or the lining of some of the body’s organs.
The extent of a cancer, which is usually assigned a number from I to IV. May be called stage grouping. See also staging.
The process of finding out whether cancer has spread and if so, how far; the process of learning the stage of a cancer. There’s more than one system for staging different types of cancer.

The TNM staging system, which is used most often, is typically based on 3 key pieces of information.

  • T refers to the main tumor (its size and/or whether it has grown into nearby areas)

  • N describes whether the cancer has spread to nearby lymph nodes

  • M shows whether the cancer has spread (metastasized) to other organs of the body

  • Letters and/or numbers after the T, N, and M give more details about each of these factors. To make this information clearer, the TNM descriptions can be grouped together into a simpler set of stages, labeled with Roman numerals (usually from I to IV). In general, the lower the number, the less the cancer has spread. A higher number means a more advanced cancer.

    The 2 main types of staging are clinical and pathologic.

  • clinical staging is an estimate of the extent of cancer based on physical exam, biopsy results, and imaging tests.

  • pathologic staging is an estimate of the extent of cancer based on the clinical stage, plus what was found during surgery.
  •  Search 
    Also called conventional treatment or mainstream treatment. The most commonly used and most widely accepted form of treatment, which has usually been tested and proven. See also clinical trials, therapy.
    See hematopoietic stem cell transplant.
    Any type of cell that can mature into different types of cells. In cancer treatment, the term usually refers to the immature blood cells found in the bone marrow and blood. Even though they start out the same, these stem cells can mature into all types of blood cells. See also bone marrow.
     Search  [steh-NO-sis]
    A narrowing (stricture) of a structure in the body such as a duct, blood vessel, or section of intestine. See also duct.
    A small hollow tube, usually made of metal or plastic, that’s put in the body to support and hold open a structure such as a blood vessel, bile duct, or section of intestine.
     Search  [STEER-ee-o-TACK-tick NEED-ul BY-op-see]
    A method of needle biopsy that may be used when calcifications or a mass can be seen on imaging tests but can’t be felt. A computer maps the location of the mass and is used to guide the needle to the area of concern. See also biopsy, calcifications, needle aspiration, needle biopsy, imaging tests.
     Search  [STEER-ee-o-TACK-tick RAY-dee-o-SUR-jer-ee]
    A type of radiation therapy that focuses a single high dose of radiation at a tumor from many different angles, which limits the damage to nearby normal tissues. Though it’s called surgery, there’s no cutting. The treatment may be useful for tumors that are in places where regular surgery would harm essential tissue, for instance, in sensitive parts of the brain or spinal cord, or when the patient is not well enough to go through regular surgery. See also radiation, spinal cord.
    Breastbone; the flat bone where the ribs meet in the center front of the chest.
     Search  [STO-muh]
    A surgically created opening from an area inside the body to the outside. For instance, a stoma on the belly (abdominal wall) that’s made to allow body waste to come out is called a colostomy. See also colostomy.
     Search  [STO-muh-TIE-tus]
    Inflammation, sores, or ulcers of the mouth. Stomatitis can be a side effect of some kinds of chemotherapy and radiation therapy.
    Also called poop or feces. Solid waste matter; feces.
    A method to detect abnormal DNA (deoxyribonucleic acid) in cells that rub off from colorectal cancers and come out in the poop (stool). This test is being studied as a screening test for colorectal cancer, but it’s not currently available. See also colorectal cancer, deoxyribonucleic acid, screening.
    A mild type of laxative that helps keep poop (stool) from becoming hard, dry, and difficult to pass. See also laxative.
    Passing a small amount of urine when coughing, laughing, sneezing, or exercising. Compare to overflow incontinence, urge incontinence, urine.
     Search  [STRIK-chur, yoo-REE-thrul]
    A narrowing of the urethra, often due to scar tissue, that blocks the flow of urine, which can result in leaking urine (overflow incontinence). This can often be treated by surgically removing the scar tissue and stretching the urethra. See also overflow incontinence, urethra, urine.
     Search  [STRO-muh]
    Connective tissue.
    See gastrointestinal stromal tumors.
     Search  [STRON-tee-um]
    A radioactive substance (radioisotope) that’s used to treat bone pain caused by cancer that has spread to the bones. It’s injected into a vein, travels through the blood, and is attracted to areas of bone that contain cancer. The radiation given off by the strontium-89 kills the cancer cells and helps relieve pain. See also radioisotope.
     Search  [SUB-mew-KO-suh]
    A layer of tissue beneath a mucous membrane. In the colon, for example, it’s between the muscularis mucosa and the muscularis propria. See also mucous membrane.
     Search  [SUE-pruh-klah-VICK-you-lar]
    The lymph nodes just above the collarbone (clavicle). See also lymph node.
     Search  [SUR-jun]
    A doctor who repairs or removes parts of the body during operations.
    Also called open surgical biopsy. Removal of tissues using open surgery so that they can be looked at under a microscope to find out if they contain cancer cells. Compare to fine needle aspiration biopsy. See also biopsy.
    Edge of the tissue removed during surgery. A negative surgical margin means no cancer cells were found on the outer edge of the removed tissue, and is considered a sign that none of the cancer was left behind. A positive surgical margin means that cancer cells are found at the outer edge of the tissue removed and is usually a sign that some cancer remains in the body. Sometimes the actual edge looks clear but the cancer cells are very close to the edge, called a narrow surgical margin. With certain fast-growing (aggressive) types of cancer, a narrow margin is reason enough for another surgery to remove more tissue. See also margin.
     Search  [SUR-jik-ul on-KAHL-uh-jist]
    A doctor who specializes in using surgery to treat cancer. See also cancer care team.
    The percentage of people alive within a certain period of time after diagnosis. For cancer, a 5-year survival rate is often given. This does not mean that people can’t live more than 5 years, nor does it mean that those who live for 5 years are permanently cured (although some might be). See also five-year survival rate, five-year relative survival rate.
    Not generally used as a medical term, survivor can have different meanings when applied to people with cancer. Some people use the word to refer to anyone who has ever been diagnosed with cancer. For example, someone living with cancer may be considered a survivor. Some people use the term to refer to someone who has completed cancer treatment. Others call a person a survivor if he or she has lived several years past a cancer diagnosis. The American Cancer Society believes that each person has the right to define his or her own experience with cancer and considers a cancer survivor to be anyone who describes himself or herself this way, from diagnosis throughout the rest of his or her life.
    The state of being a cancer survivor, that is, having been diagnosed with cancer. See also survivor.
     Search  [SIMP-tuhm]
    A change in the body caused by an illness or condition, as described by the person experiencing it. Compare to sign.
     Search  [SIN-kruh-nus]
    Occurring at the same time; for example, cancer in both breasts at the same time is synchronous. Compare to metachronous.
     Search  [SIN-er-JIS-tick]
    Acting together. A synergistic agent can act together with one or more other agents to produce an effect greater than their individual effects. Some chemotherapy drugs act synergistically. See also chemotherapy.
     Search  [sis-TEM-ick]
    In cancer, this term means that a cancer that started in one place has spread to distant organs or structures. Compare to carcinoma in situ, localized cancer.
     Search  [sis-TEM-ick]
    Treatment that reaches and affects cells throughout the body; for example, chemotherapy. Compare to local therapy. See also chemotherapy.