Common cancer related terms explained

absolute risk

The actual chance of experiencing a particular event in a defined time period. In cancer, absolute risk is typically expressed per 1,000 or per 100,000. For a person age 50, for example, the absolute risk of death from colon cancer in the next 10 years is 3 per 1,000. See also relative risk.

barium enema

Atest in which a tube is inserted in the rectum and a thick fluid is allowed to flow up the colon by gravity. Because the fluid is impenetrable by X-rays, when an X-ray is taken the radiologist can see the outline of the colon.

biopsy

The entire process of obtaining human tissue so that it might be examined under a microscope by a pathologist. The tissue is obtained either using a needle (needle biopsy) or by cutting out a section with a knife (excisional biopsy).

bronchoscopy

Aprocedure in which a fiber-optic instrument is passed through the mouth and down the trachea (windpipe) to examine the lung. Although the technology is comparable to sigmoidoscopy and colonoscopy, the exam is technically more challenging because the natural response to having a tube introduced in your throat is either to gag or to swallow it (in which case the stomach would be examined).

cancer

In common usage, "a cellular tumor the natural course of which is fatal"; in practice, a diagnosis made on the decoration of individual cells and the architecture of collections of cells.

carcinoma in situ

Cancer that involves only the cells in which it began and that has not spread to neighboring tissues.

CAT scan

Computerized axial tomography: an imaging procedure in which X-rays are manipulated in a computer to create a series of detailed pictures, viewable from different angles, of areas inside the body. Also called computerized tomography (CT scan).

colonoscopy

An examination of the entire colon using a fiber-optic scope.

colposcopy

A procedure when the cervix is examined with an instrument inserted in the vagina.

control group

In a randomized trial, the group that doesn't receive the intervention being studied (either a test or a treatment). The control group typically receives conventional medical care, while the intervention group receives the test or treatment. Investigators compare the outcomes for the two groups to determine whether the intervention is better or worse than the conventional approach.

DCIS

Ductal carcinoma in situ: a tiny form of breast cancer involving a generally microscopic cancer that is confined to the breast ducts.

false positive

A test result that suggests cancer is present when it in fact is not. Also known as a "cancer scare." fecal occult blood test A screening test for colon cancer in which the patient spreads a small amount of stool onto a thin cardboard card. The card is sent to the laboratory where occultblood blood not visible to the human eye can be detected using a chemical reaction. Blood in the stool can be the result of many things, one of which is colon cancer.

fiber-optic scope

An instrument used to visualize the internal anatomy of hollow organs (e.g., stomach, colon, lungs). The long, flexible scope, containing thin strands of glass (or plastic) to transmit light, can even be directed around corners. The instrument also includes numerous tubes through which fluid (to wash off surfaces), air (to inflate the organ) and small surgical instruments (to biopsy worrisome tissue) can be passed.

five-year survival rate

Proportion of individuals diagnosed with cancer who are alive five years after diagnosis. Although this statistic is generally seen as reflecting the effectiveness of cancer treatment, it is greatly influenced by cancer testing. Five-year survival will increase whenever cancers are diagnosed earlier, even if the time of death is not postponed.

incidence

The rate of new cases of disease in a population; often calculated for a specific cancer (e.g., breast cancer incidence).

interval cancer

cancer that becomes apparent in the period between two screening tests. Interval cancers are usually particularly aggressive (fast growing).

intervention group

In a randomized trial, the group that receives the intervention being studied (either a test or a treatment). See also control group.

mammography

An X-ray exam of the breast. Used either as a screening test in women without symptoms of breast cancer or as a diagnostic test in women (and occasionally men) with a breast mass.

metastasis

The spread of cancer from one part of the body to distant sites in the body. Also the name given to the secondary tumor thus produced, a discrete collection ofcancer cells that are separate from the original (primary) cancer.

metastasize

To spread from one part of the body to another. metastatic Having to do with metastasis. morbidity The quantity of sickness or ill health in a population, excluding death. The term also encompasses the adverse effects of treatment. Morbidity and mortality combined thus become a comprehensive measure of population health.

mortality rate

The rate of death in a population; often calculated for a specific cancer (e.g., breast cancer mortality). MRI Magnetic resonance imaging: an imaging procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body. natural history The natural course of an untreated disease. needle biopsy Removing tissue or fluid with a needle for examination under a microscope.

Pap smear

Ascreening test for cervical cancer in which cells are collected from the cervix during a pelvic exam and examined under the microscope.

pathologist

A physician who specializes in examining human tissue under the microscope and who ultimately makes the diagnosis of cancer.

PET scan

Positron emission tomography scan: an imaging procedure that detects the metabolic activity of body tissues. preclinical phase The time frame that begins when a cell first becomes cancerous and ends when the cancer is large enough that it causes symptoms. The preclinical phase is thus the period during which a screening test could potentially detect the cancer.

PSA test

The blood test for prostate cancer; PSA stands for prostate specific antigen.

pseudodisease

Cancers that never cause symptoms, either because they don't grow at all or they grow so slowly that people die of other causes before symptoms appear. randomized trial An experiment in which study participants are assigned to groups on the basis of chance. This is the easiest method to ensure that study groups are similar and that differences observed are the result of the experiment itself, not of skewed population samples. See also control group; intervention group.

relative risk

The ratio of one absolute risk to another. Relative risk increases are typically expressed as% ages or factors (e.g., "20% higher" or "twice as high"). Relative risk decreases are typically expressed as a%age reduction in absolute risk. For a person age 50 undergoing fecal occult blood testing, for example, the relative risk of death from colon cancer is 33% lower than for a similar-aged person who is not screened (i.e., 2 per 1,000 vs. 3 per 1,000, or 33% less). See also absolute risk.

sigmoidoscopy

A procedure in which a fiber-optic instrument is used to examine the lower colon. Inserted into the rectum and advanced partway up the colon, the instrument shines light in both directions and can transmit images back to a television monitor. The instrument also includes a number of tubes through which fluid (to wash off surfaces), air (to inflate the colon), and small surgical instruments (to biopsy worrisome tissue) can be passed. tissue Agroup or layer of cells that are alike and that work together to execute a specific function.

tumor

An abnormal growth (mass of tissue) that's the product of excessive cell division. Although in common usage often equated with cancer, a tumor can also be a benign growth.

ultrasound

A technique employing a machine that sends and receives sound waves, much like a radar. Particularly good for distinguishing liquids from solids, it is used in the breast, heart (where it is typically called an echocardiogram), abdomen, and rectum (to examine the prostate).

Common cancer related terms explained

Legal Disclaimer

Related Articles