SENSITIVITY, SPECIFICITY AND POSITIVE PREDICTIVE VALUE OF PSA, PSA-DENSITY, DIGITAL RECTAL EXAMINATION AND TRANSRECTAL ULTRASONOGRAPHY IN THE EARLY DETECTION OF PROSTATE-CANCER

The results of 255 systematic biopsies of the prostate from 1992 and 1993 were evaluated retrospectively and compared with the histological specimen. We examined digital rectal examination (DRE), transrectal ultrasound (TRUS) and prostate-specific antigen (PSA). Besides these single parameters and possible combinations we analysed age-specific-PSA-reference values and calculated the PSA-density. The sensitivity for the single parameters was about 90%; the highest value (94.2%) was obtained by TRUS with a specificity of 38.1%. Age-specific-PSA-values had a comparable specificity (38.4%), but sensitivity was only 80.8%. The PSA-density (cut-off level 0.15) for patients with PSA-values between 2.0 and 10.0 ng/ml had a sensitivity of just 20%, but specificity was very high (81.8%). The combination of DRE and PSA for screening of PC seems to be the best compromise in terms of good sensitivity, simple application and cost-efficiency. Transrectal ultrasound should be applied additionally if PSA or DRE indicates suspicion of carcinoma. The combination of DRE, TRUS and PSA above 10 ng/ml has the highest positive predictive value (80.7%).