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GLOSSARY
Bias: a process at any stage of inference tending to produce results that depart systematically from the true values.
Biopsy: excision of a small piece of tissue for diagnostic examination; can be done surgically or with needles.
BRCA1: a gene located on the short arm of chromosome 17; when this gene is mutated, a woman is at greater risk of developing breast or ovarian cancer, or both, than women who do not have the mutation.
BRCA2: a gene located on chromosome 13; a germ-line mutation in this gene is associated with increased risk of breast cancer.
Breast self-examination: monthly physical examination of the breasts with the intent of finding lumps that could be an early indication of cancer.
Cell culture: the growth of cells in vitro for experimental purposes.
Clinical breast examination: a physical examination of the breasts, performed by a doctor. or nurse, with the intent of finding lumps that could be an early indication of cancer.
Clinical outcome: the end result of a medical intervention, e.g., survival or improved health.
Clinical trial: a formal study carried out according to a prospectively defined protocol that is intended to discover or verify the safety and effectiveness of procedures or interventions in humans. The term may refer to a controlled or uncontrolled trial.
Computer-aided detection: use of sophisticated computer programs designed to recognize patterns in images.
Contrast agent: a substance that enhances the image produced by medical diagnostic equipment such as ultrasound, X ray, magnetic resonance imaging, or nuclear medicine or and imaging-sensitive substance that is ingested or injected intravenously to enhance or increase contrast between anatomical structures.
Cost-effectiveness analysis: methods for comparing the economic efficiencies of different therapies or programs that produce health.
Detection: finding disease. Early detection means that the disease is found at an early stage, before it has grown large or spread to other sites.
Diagnosis: confirmation of a specific diseaseusually by imaging procedures and from the use of laboratory findings.
Diagnostic mammography: X-ray-based breast imaging undertaken for the purpose of diagnosing an abnormality discovered by physical exam or screening mammography.
Digital mammography: see full-field digital mammography.
DNA: abbreviation for deoxyribonucleic acid. DNA holds genetic information for cell growth, division, and function.
Duct: a hollow passage for gland secretions. In the breast, a passage through which milk passes from the lobule (which makes the milk) to the nipple.
Ductal carcinoma in situ: a lesion in which there is proliferation of abnormal cells within the ducts of the breast, but no visible evidence of invasion into the duct walls or surrounding tissues; sometimes referred to as “precancer” or “preinvasive cancer.”
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Ductal lavage: a procedure in which a small catheter is inserted into the nipple and the breast ducts are flushed with fluid to collect breast cells.
Effectiveness: the extent to which a specific test or intervention, when used under ordinary circumstances, does what it is intended to do.
Epidemiology: science concerned with defining and explaining the interrelationships of factors that determine disease frequency and distribution.
False-negative result: a test result that indicates that the abnormality or disease being investigated is not present when in fact it is.
False-positive result: a test result that indicates that the abnormality or disease being investigated is present when in fact it is not.
Fine-needle aspiration: a procedure by which a thin needle is used to draw up (aspirate) samples for examination under a microscope.
Full-field digital mammography: similar to conventional mammography (film-screen mammography) except that a dedicated electronic detector system is used to computerize and display the X-ray information.
Gene: a functional unit of heredity that occupies a specific place or locus on a chromosome.
Invasive cancer: cancers capable of growing beyond their site of origin and invading neighboring tissue.
Invasive ductal carcinoma: a cancer that starts in the ducts of the breast and then breaks through the duct wall, where it invades the surrounding tissue; it is the most common type of breast cancer and accounts for about 80 percent of breast malignancies.
Invasive lobular carcinoma: a cancer that starts in the milk-producing glands (lobules) of the breast and then breaks through the lobule walls to involve the surrounding tissue; accounts for about 15 percent of invasive breast cancers.
Lead-time bias: the assumption that identifying and treating tumors at an earlier point in the progression of the disease will necessarily alter the rate of progression and the eventual outcome.
Length bias: the assumption that screening tests are more likely to identify slowly growing tumors than those with a fast growth rate.
Lobular carcinoma in situ: abnormal cells within a breast lobule that have not invaded surrounding tissue; can serve as a marker of future cancer risk.
Magnetic resonance imaging: method by which images are created by recording signals generated from the excitation (the gain and loss of energy) of elements such as the hydrogen of water in tissue in a magnetic field.
Malignant: a tumor that has the potential to become lethal through destructive growth or by having the ability to invade surrounding tissue and metastasize.
Mammogram: X-ray image of the breast.
Mammography: technique for imaging breast tissues with X rays.
Medicaid: jointly funded federal-state health insurance program for certain low-income and needy people. It covers approximately 36 million individuals including children; aged, blind, and/or disabled people; and people who are eligible to receive federally assisted income maintenance payments.
Medicare: a program that provides health insurance to people age 65 and over, those who have permanent kidney failure, and people with certain disabilities.
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Microcalcifications: tiny calcium deposits within the breast, singly or in clusters; often found by mammography. They may be a sign of cancer.
Molecular markers: changes in cells, at the molecular level, that are indicative of cancer or malignant potential.
Mortality: the death rate; ratio of number of deaths to a given population.
Overdiagnosis: labeling an abnormality as cancer when it in fact is not likely to become a lethal cancer.
Palpable tumor: a tumor that can be felt during a physical examination.
Positron emission tomography: use of radioactive tracers such as labeled glucose to identify regions in the body with altered metabolic activity.
Premalignant: changes in cells that may, but that do not always, become cancer. Also called “precancer.”
Prognosis: prediction of the course and end of disease and the estimate of chance for recovery.
Prophylactic bilateral mastectomy: surgical removal of both breasts with the intent of reducing the risk of developing breast cancer later in life.
Randomization: a method that uses chance to assign participants to comparison groups in a trial by using a random-numbers table or a computer-generated random sequence. Random allocation implies that each individual being entered into a trial has the same chance of receiving each of the possible interventions.
Risk: a quantitative measure of the probability of developing or dying from a particular disease such as cancer.
Scintimammography: use of radioactive tracers to produce an image of the breast.
Screen-film mammography: conventional mammography in which the X rays are recorded on film.
Screening: systematic testing of an asymptomatic population to determine the presence of a particular disease or certain risk factors known to be associated with the disease.
Screening mammography: X-ray-based breast imaging in an asymptomatic population with the goal of detecting breast tumors at an early stage.
Sensitivity: a measure of how often a test correctly identifies women with breast cancer.
Specificity: a measure of how often a test correctly identifies a woman as not having breast cancer.
Specimen bank: stored patient tissue samples that are used for biomedical research (also tumor or tissue banks).
Tomography: any of several techniques for making X-ray pictures of a predetermined plane section of a solid object by blurring out the images of other planes.
Tumor marker: any substance or characteristic that indicates the presence of a malignancy.
Ultrasound: use of inaudible, high-frequency sound waves to create an image of the body.