Clinical behavior of prostatic specific antigen and prostatic acid phosphatase: a comparative study.

We assayed prostatic specific antigen and prostatic acid phosphatase serum levels in 1,383 patients using a double antibody radioimmunoassay (RIA) 125I. Establishing the upper normal limit in 10 ng/ml for prostatic specific antigen and 2.5 ng/ml for prostatic acid phosphatase, the false positive results were only 1.9 and 5.1% in men with nonprostatic benign or malignant pathology and 0 and 2.2% in women, respectively. We detected false positive levels in 3.5 and 4.7% of the patients with noncomplicated benign prostatic hypertrophy, 64.8 and 19.2% in complicated benign prostatic hypertrophy, 24 and 16% in acute prostatitis and 3.3% in chronic prostatitis for both tumoral markers. The sensibility in patients with prostate cancer was 87.2 and 64.1%, respectively, and there was better correlation with prostatic specific antigen than prostatic acid phosphatase levels on tumoral spread and histologic grading. Finally, the clinical efficacy was higher with prostatic specific antigen and it did not increase with the quantification of both tumoral markers.