Glossary


Accuracy

—the degree to which a test measures the true value of the attribute it is testing.

Adiposity

—the quality or state of being fat: obesity.

Ambulatory care

—the use of outpatient facilities—doctors’ offices, home care, outpatient hospital clinics, and day-care facilities—to provide medical care without the need for hospitalization. Often refers to any care outside a hospital.


Beta-carotene

—an antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A.

Bias

—in general, any factor that distorts the true nature of an event or observation. In clinical investigations, a bias is any systematic factor other than the intervention of interest that affects the magnitude of (i.e., tends to increase or decrease) an observed difference in the outcomes of a treatment group and a control group.

Biopsy

—refers to a procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis.

BRCA1

—gene located on the short arm of chromosome 17; when damaged (mutated), a woman is at greater risk of developing breast and/or ovarian cancer compared to women who do not have the mutation.

BRCA2

—mutation of this gene, located on chromosome 13, is associated with increased risk of breast cancer.

Bupropion

—a unicyclic, aminoketone antidepressant. The mechanism of its therapeutic actions is not well understood, but it does appear to block dopamine uptake. It is effective in the treatment of major depression and has some beneficial effects in children and adults with attention deficit disorder.


Cancer

—a general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells. Cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body.

Carcinogenesis

—the generation of cancer, uncontrolled, abnormal growth, from normal cells; correctly the formation of a carcinoma from epithelial cells, but often used synonymously with transformation, tumorigenesis.



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Fulfilling the Potential of Cancer Prevention and Early Detection Glossary Accuracy —the degree to which a test measures the true value of the attribute it is testing. Adiposity —the quality or state of being fat: obesity. Ambulatory care —the use of outpatient facilities—doctors’ offices, home care, outpatient hospital clinics, and day-care facilities—to provide medical care without the need for hospitalization. Often refers to any care outside a hospital. Beta-carotene —an antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A. Bias —in general, any factor that distorts the true nature of an event or observation. In clinical investigations, a bias is any systematic factor other than the intervention of interest that affects the magnitude of (i.e., tends to increase or decrease) an observed difference in the outcomes of a treatment group and a control group. Biopsy —refers to a procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis. BRCA1 —gene located on the short arm of chromosome 17; when damaged (mutated), a woman is at greater risk of developing breast and/or ovarian cancer compared to women who do not have the mutation. BRCA2 —mutation of this gene, located on chromosome 13, is associated with increased risk of breast cancer. Bupropion —a unicyclic, aminoketone antidepressant. The mechanism of its therapeutic actions is not well understood, but it does appear to block dopamine uptake. It is effective in the treatment of major depression and has some beneficial effects in children and adults with attention deficit disorder. Cancer —a general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells. Cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body. Carcinogenesis —the generation of cancer, uncontrolled, abnormal growth, from normal cells; correctly the formation of a carcinoma from epithelial cells, but often used synonymously with transformation, tumorigenesis.

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Fulfilling the Potential of Cancer Prevention and Early Detection Case-control study —a retrospective observational study in which investigators identify a group of patients with a specified outcome (cases) and a group of patients without the specified outcome (controls). Investigators then compare the histories of the cases and the controls to determine the extent to which each was exposed to the intervention of interest. Case report —a description of a single case, typically describing the manifestations, clinical course, and prognosis of that case. Case series —a descriptive, observational study of a series of cases, typically describing the manifestations, clinical course, and prognosis of a condition. Chemoprevention —the use of natural or laboratory-made substances to prevent cancer. Chemoprophylaxis —drug treatment designed to prevent future occurrences of disease. Chemotherapy —the treatment of disease by means of chemicals that have a specific toxic effect upon the disease producing microorganisms (antibiotics) or that selectively destroy cancerous tissue (anticancer therapy). Cohort study —an observational study in which outcomes in a group of patients that received an intervention are compared with outcomes in a similar group, that is, the cohort, either contemporary or historical, of patients that did not receive the intervention. In an adjusted- (or matched-) cohort study, investigators identify (or make statistical adjustments to provide) a cohort group that has characteristics (e.g., age, gender, disease severity) that are as similar as possible to the group that experienced the intervention. Colonoscopy —an endoscopic (fiberoptic) examination of the large intestine (colon). Computed tomography —a special radiographic technique that uses a computer to assimilate multiple X-ray images into a two-dimensional, cross-sectional image. This can reveal many soft tissue structures not shown by conventional radiography. Confidence interval —a range within which an estimate is deemed to fall with specified statistical confidence. Confounding factors —factors for which data adjustment is needed because they are entangled with other factors related to the disease or condition of interest. Controlled observational studies —studies that compare outcomes among those who do or do not receive screening. Cost-benefit analysis —a comparison of alternative interventions in which costs and outcomes are quantified in common monetary units. Cost-effectiveness analysis —a comparison of alternative interventions in which costs are measured in monetary units and outcomes are measured in non-monetary units, for example, reduced mortality or morbidity. Cross-sectional comparison —an observational study in which both risk factor(s) and disease are ascertained at the same time. Cytological screening —examination of cells for changes indicative of a disease or risk of disease, for example, Papanicolaou test. Diagnostic testing —the evaluation of patients with signs or symptoms associated with a disease. DNA (deoxyribonucleic acid) —the genetic material of all cells and many viruses that is a polymer of nucleotides. The monomer consists of phosphorylated 2-deoxyribose N-glycosidically linked to one of four bases: adenine, cytosine, guanine or thymine. The sequence of these bases encodes genetic information. Dose-response —the relation between the dose of a drug or other chemical and the degree of response it produces, as measured by the percentage of the exposed population showing a defined, often quantal, effect. Dosimetry —measurement of the amount of X-rays and radioactivity absorbed. Ductal carcinoma in situ —a very early form of breast cancer confined to cells lining the breast ducts.

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Fulfilling the Potential of Cancer Prevention and Early Detection Etiology —the science and study of the causes of disease and their mode of operation. Exercise —a subset of physical activity that is planned, structured, and repetitive. False-negative result —relating to or being an individual or a test result that is erroneously classified in a negative category (as of diagnosis) because of imperfect testing methods or procedures. False-positive result —relating to or being an individual or a test result that is erroneously classified in a positive category (as of diagnosis) because of imperfect testing methods or procedures. Genotype —the genetic constitution of an organism or cell, as distinct from its expressed features or phenotype. Health Maintenance Organization (HMO) —organized system for providing comprehensive prepaid health care that has five basic attributes: 1) provides care in a defined geographic area; 2) provides or ensures delivery of an agreed-upon set of basic and supplemental health maintenance and treatment services; 3) provides care to a voluntarily enrolled group of persons; 4) requires their enrollees to use the services of designated providers; and 5) receives reimbursement through a predetermined, fixed, periodic pre-payment made by the enrollee without regard to the degree of services provided. Health services research —a multidisciplinary field of inquiry, both basic and applied, that examines the use, costs, quality, accessibility, delivery, organization, financing, and outcomes of health care services to increase knowledge and understand the structure, processes, and effects of health services for individuals and populations. Human papillomavirus —any of numerous papillomaviruses that cause various human warts (as the common warts of the extremities, plantar warts, and genital warts) including some associated with the production of cancer; called also HPV. Hyperplasia —A condition in which there is an increase in the number of normal cells in a tissue or organ. Incidence —the number of new cases of a disease that occur in the population per unit of time. Indemnity plan —traditional health insurance plans that pay for all or a share of the cost of covered services, regardless of which doctor, hospital, or other licensed health care provider is used. Members choose when and where to get health care services. In exchange for the premiums that members pay, the indemnity plan either pays the provider directly or reimburses members when they file claims. Intermediate outcomes —findings that are not health outcomes in themselves (e.g., cellular atypia) but that precede or that are thought to increase the risk of such outcomes. Lead-time bias —overestimation of survival time because of the backward shift in the starting point for the measurement of survival as a result of early detection. Length bias —the tendency of screening to detect slowly growing lesions more readily than aggressive cancers. Lifetime probability —the probability of being diagnosed with a specified cancer during an individual’s lifetime, expressed as percent. It is derived by summing all cancer cases from age 0 through 95+ and dividing by 100,000 × 100 (expressed as percent). Mammography —the practice of taking diagnostic X-ray pictures of breasts to produce a mammogram. Managed care —any system that manages healthcare delivery to control costs. Meta-analysis —systematic methods that use statistical techniques for combining results from different studies to obtain a quantitative estimate of the overall effect of a particular

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Fulfilling the Potential of Cancer Prevention and Early Detection intervention or variable on a defined outcome. This combination may produce a stronger conclusion than can be provided by any individual study (also known as data synthesis or quantitative overview). Metabolism —the sum of all the physical and chemical processes by which living organized substance is produced and maintained (anabolism) and also the transformation by which energy is made available for the uses of the organism (catabolism). Metaplasia —the change in the type of adult cells in a tissue to a form which is not normal for that tissue. Molecular epidemiology —a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution, and prevention of disease within families and across populations. Morbidity —a diseased condition or state, the incidence of a disease or of all diseases in a population. Mortality rate —expresses the number of deaths in a unit of population within a prescribed time and may be expressed as crude death rates or as death rates specific for diseases and, sometimes, for age, sex, or other attributes. Nulliparity —condition of not having given birth to a child. Observational studies —follow-up studies where clinical interventions are not specified by protocol. Odds ratio —a comparison of the presence of a risk factor for disease in a sample of diseased subjects and non-diseased controls. Oncology —the study of diseases that cause cancer. Pap smear —a cytological test developed by George N. Papanicolaou for the detection of cervical cancer. Pharmacotherapy —treatment or therapy using drugs. Phenotype —the observable characteristic of an organism, the expression of the gene alleles (genotype) as an observable physical or biological trait. Physical activity —any bodily movement produced by skeletal muscles that results in energy expenditure. Population attributable risk —the proportion of all cancers in the population due to a particular risk factor. Its calculation relies on estimates of relative risk, which is the ratio of the cancer incidence rate among those exposed to a risk factor divided by the rate among those not exposed and the proportion of the population exposed to that risk factor. Positive predictive value —the probability that an abnormal result correctly indicates cancer. Prevalence —the number of cases of disease, infected persons, or persons with some other attribute, present at a particular time and in relation to the size of the population from which drawn. Primary cancer prevention —prevention of acquisition of cancer. Prophylaxis —the prevention of disease, preventive treatment. PSA (prostate-specific antigen) testing —used to screen for cancer of the prostate and to monitor treatment by measuring the amount of PSA in the blood. PSA is a protein produced in the bloodstream. p-value —the probability that an outcome as large as or larger than that observed would occur in a properly designed, executed, and analyzed analytical study if in reality there was no difference between the groups. Randomized controlled trial —a true prospective experiment in which investigators randomly assign an eligible sample of patients to one or more treatment groups and a control

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Fulfilling the Potential of Cancer Prevention and Early Detection group and follow patients’ outcomes (also known as randomized clinical trial). Relative risk —the proportion of diseased people among those exposed to the relevant risk factor divided by the proportion of diseased people among those not exposed to the risk factor. This statistic should be used in those cohort studies where those with and without disease are followed to observe which individuals become diseased. Reliability —the consistency of the result when a test is repeated. Screening —early detection of cancer or premalignant disease in persons without signs or symptoms suggestive of the target condition (the type of cancer that the test seeks to detect). Secondary cancer —cancer that has spread from the site where it first appeared to another site. Sigmoidoscopy —a procedure in which a scope is used to view the sigmoid flexure. Specificity —the proportion of persons without disease who correctly test negative. Spiral computed tomography —a detailed cross-sectional picture of areas inside the body. The images are created by a computer linked to an X-ray machine that scans the body in a spiral path. Also called helical computed tomography. Squamous cell carcinoma —a malignant growth originating from a squamous cell. This form of cancer can be seen on the skin, lips, and inside the mouth, throat, or esophagus. Statistical power —the likelihood that a study will find a particular effect if the effect exists. Surrogate outcomes —indicators that correlate with, but that are not themselves, health outcomes (e.g., length of hospital stay). Surveillance —close and continuous observation, screening, and testing of those at risk for a disease. Survival —average period of time from diagnosis to death. Translational research —the research needed to move the fruits of research into provider and community practice. Tumor —an abnormal mass of tissue that results from excessive cell division that is uncontrolled and progressive, also called a neoplasm. Tumors perform no useful body function. They may be either benign (not cancerous) or malignant. Venipuncture —the puncture of a vein (usually in the arm) with a hollow bore needle for the purpose of obtaining a blood specimen. X-ray —a type of irradiation used for imaging purposes that uses energy beams of very short wavelengths (0.1 to 1000 angstroms) that can penetrate most substances except heavy metals.

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