Serum prostatic acid phosphatase determination in prostatic diseases: a critical comparison of an enzymatic and a radioimmunologic assay.

A prospective study comparing a new radioimmunologic and a classical enzymatic assay for prostatic acid phosphatase was done to evaluate their respective roles in patients with prostatic diseases. We studied 50 patients with cancer of the prostate, 101 with benign prostatic hypertrophy and 17 with prostatitis as well as patients with nonprostatic malignancy, and various hematological and bone diseases. The results showed a low incidence of elevated values in patients with early cancer of the prostate and a high incidence of false positive values with the radioimmunoassay in patients with benign prostatic diseases, especially prostatitis. These data suggest that tests for serum prostatic acid phosphatase levels remain disappointing in the assessment of prostatic disease regardless of the technique used.