The efficacy of screening for carcinoma of the prostate by digital examination.

Screening for carcinoma of the prostate by digital examination has been frequently advocated. In the United States prostate cancer is an important health problem for which current treatment is unsatisfactory; most patients with progressive disease die of the condition. While the pattern of spread of prostate cancer is understood, rates of progression of early disease are unknown. There has been no randomized clinical trial of digital examination in screening for prostate cancer; and thus, whether prognosis is definitely improved by early detection is unknown. Measures of test performance--test sensitivity and specificity--are unknown for an asymptomatic screened population. Interpreting the results of treatment for asymptomatic cases diagnosed by screening is difficult because of selection bias, lead time bias, and possible overdiagnosis of nonprogressive cancers. The limited cost-efficacy of routine digital examination of the prostate should be compared with the cost-efficacy of other routine health care in deciding about the use of this procedure.