title: Scientific basis of screening in early detection.
abstract: The basis of screening for cancer is related to the natural history of the disease, to the screening test, to the treatment of preinvasive lesions, and to the application of a screening program at a population level. It is not only the test but the total program that should be valid, ie, detect both those having a preinvasive abnormality and those being healthy. The only reliable indicator on the efficacy of a screening program is the reduction in the mortality from the cancer subjected to screening. The reduction in mortality should be assessed by a randomized preventive trial. There are several examples on inconclusive evidence stemming from observational studies and based on indicators other than mortality.
mesh_terms: D001943:Breast Neoplasms / Q000453:epidemiology / Q000401:mortality; D005060:Europe; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008403:Mass Screening; D009369:Neoplasms / Q000175:diagnosis / Q000517:prevention & control*