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Cancer Glossary

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

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A state of being very overweight; in general, a body mass index (BMI) greater than 30. BMI is figured out based on height and weight, but is not an absolute measure for overweight or obesity. Because it cannot tell the difference between fat and muscle, other tests must be done to know whether a person with a high BMI is actually obese.
 Search  [uh-KULT or o-KULT]
Hidden or concealed. In cancer screening, can refer to small amounts of blood in poop (stool) that can’t be seen without special tests. See also fecal occult blood test, colorectal cancer screening.
 Search  [OK-you-PAY-shun-uhl]
A specially trained therapist who works with people with impairments or limitations to help them develop, recover, and improve the skills needed for daily living and working. See also cancer care team.
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The use of a drug to treat a condition other than that for which it was approved by the Food and Drug Administration (FDA). See also investigational.
 Search  [o-MEN-tum]
A large fatty sheet in the belly (abdomen) that drapes like an apron over the stomach, intestines, and other organs.
 Search  [ON-kuh-jeenz]
Changed (mutated) forms of genes that cause cells to grow, divide to make new cells, or stay alive longer than they should. Oncogenes are related to normal genes called proto-oncogenes that control normal cell growth. But oncogenes have undergone changes that activated them, which can result in cells growing out of control and becoming cancer. Compare to tumor suppressor genes. See also genes, mutation, proto-oncogenes, tumors.
 Search  [on-KAHL-uh-jist]
A doctor with special training in the diagnosis and treatment of cancer. See also cancer care team.
 Search  [on-KAHL-o-jee]
The branch of medicine concerned with the diagnosis and treatment of cancer. See also cancer.
 Search  [on-KAHL-o-jee]
A registered nurse with a master’s degree who specializes in the care of people with cancer. Oncology nurse specialists may prepare and give treatments, monitor patients, prescribe and provide supportive care, and teach and counsel patients and their families. See also cancer care team.
 Search  [on-KAHL-o-jee]
A person with a master’s degree in social work who is an expert in coordinating and providing non-medical care to patients. The oncology social worker counsels and assists people with cancer and their families, especially in dealing with the non-medical issues of cancer, such as financial problems, housing (when treatments are given at a facility away from home), and child care. See also cancer care team.
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Techniques that combine cancer care (oncology) with plastic surgery.
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In breast cancer treatment, surgery done right after the procedure done to diagnose the cancer (the biopsy). The patient is given general anesthesia and does not know until waking up if the diagnosis was cancer or if extensive surgery (for instance mastectomy) was done. Once the only option in breast cancer, the one-step procedure is now rarely used, having been replaced by a two-step approach. See also anesthesia, biopsy, mastectomy, two-step procedure.
 Search  [oh-of-uh-REK-tuh-me]
Surgery to remove the ovaries. The fallopian tubes are often removed at the same time (salpingo-oophorectomy). See also fallopian tubes, ovary.
 Search  [OFF-thuhl-MAHL-uh-jist]
A medical doctor who specializes in eye diseases.
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Refers to the mouth. For example, medicines that are taken orally are taken by mouth. Oral cancer is cancer of the mouth.
 Search  [MAX-ill-o-FAY-shul]
A surgeon who specializes in operating on the mouth, jaw, and face.
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Birth control pills, which contain estrogen and/or a progesterone-like substance, known as progestin. See also estrogen, hormone, progesterone.
 Search  [OR-key-ECK-tuh-me]
Surgery to remove the testicles; also called castration. See also hormone therapy, testicles.
 Search  [OR-oh-FAIR-ingks]
The part of the throat (pharynx) below the soft palate and above the epiglottis, mostly behind the mouth. See also epiglottis, pharynx.
 Search  [or-thuh-PEE-dik]
A surgeon who specializes in diseases and injuries of the muscles, joints, and bones.
 Search  [OS-tee-o-nuh-CROW-sis]
Often shortened to ONJ. In this condition, part of the jaw bone loses its blood supply and dies. This can lead to tooth loss and infections or open sores of the jaw bone that won’t heal and are hard to treat. Drugs called bisphosphonates can cause this rare side effect. See also bisphosphonates.
 Search  [OS-tee-o-puh-RO-sis]
Thinning of bone tissue, causing weaker bones. It’s more common in older people and in people who have had certain types of cancer treatments. Osteoporosis can cause pain, deformity (especially of the spine), and broken bones. See also spine.
 Search  [OS-tee-oh-sar-KO-muh]
Also called osteogenic sarcoma. A type of cancer that starts in the bones and is mainly seen in teens and children, although it’s also seen in young adults.
 Search  [OS-tuh-me]
A general term meaning an opening, especially one made by surgery. See also colostomy, ileostomy, tracheostomy, urostomy.
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See enterostomal therapist.
 Search  [O-toe-LAIR-in-GOL-uh-jist]
Also called a head and neck surgeon or an ENT (ear, nose, throat doctor); a doctor who specializes in diseases of the ear, nose, and throat.
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A person being treated without staying in the hospital. Compare to inpatient. See also ambulatory.
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The eggs that are released (usually one at a time) from the ovaries about once a month during a woman’s reproductive (fertile) years. The egg must be fertilized by a sperm to grow into a baby. A female is born with all the ova she will ever have. The singular of ova is ovum. See also ovary, sperm.
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Removal of the ovaries or the use of radiation or drugs to stop their function. See also ablation, ovary, hormone therapy.
 Search  [O-vuh-ree]
Reproductive organ in the female pelvis. Normally a woman has 2 ovaries. They contain the eggs (ova) that, when joined with sperm, can result in pregnancy. Ovaries are also the main source of estrogen, the main female sex hormone. See also estrogen, ova, sperm.
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Urine leak that happens when the bladder can’t be emptied. A person with overflow incontinence may need to get up often during the night to urinate, take a long time to urinate, and/or have a dribbling stream with little force. Overflow incontinence is usually caused by blockage or narrowing of the bladder outlet, such as from cancer or scar tissue. Compare with stress incontinence, urge incontinence, urine.