THE BENEFIT AND COST OF PROSTATE-CANCER EARLY DETECTION

Cost-effectiveness calculations of prostate cancer early detection hav e not been possible due to the lack of any data demonstrating reductio n in mortality from any test or procedure. Prior analyses focused only on cost assessments without consideration of any possible benefits. W e used current data from three consecutive years of the American Cance r Society-National Prostate Cancer Detection Project to assess differe nt economic perspectives of test performance, marginal costs, and bene fit-cost analysis. The marginal cost, or cost per cancer, of digital r ectal examination (DRE) markedly increased by the third year relative to several proposed prostate-specific antigen (PSA) scenarios. Sensiti vity analysis for average cost showed that at 4 ng/ml, pricing PSA bel ow $30 would be the most potent factor in potentially lowering costs. Analysis of receiver operator characteristic curves suggested that opt imal performance for PSA may be at 3 ng/ml when combined with DRE or b etween 2 to 3 ng/ml when used alone. Benefit-cost calculations demonst rated that DRE when performed by highly skilled examiners had the lowe st cost. However, DRE became one of the most costly detection scenario s when a minor decrease in performance was assumed. Sensitivity analys is demonstrated that the three most determinant parameters of net bene fit, in decreasing order, are: specificity, benefits from earlier ther apy, and prevalence. If a slightly more specific PSA assay is develope d, the higher prevalence of clinically detectable prostate cancer coul d also make screening less costly than breast cancer screening. Under the assumptions of these analyses, the combination of PSA and DRE appe ars to represent an ethical and economical detection choice for indivi dual patients in consultation with their physicians. Additional resear ch is needed to quantify the significance of differences between diffe rent screening strategies.