The significance of prostatic acid phosphatase in adenocarcinoma of the prostate.

Our radioimmunoassay for prostatic acid phosphatase was compared to commercial radioimmunoassay kits. A close correlation among all 3 assays was found in control groups, and in patients with benign prostatic hyperplasia and adenocarcinoma of the prostate. These results also were compared to recent reports from other centers using similar methodologies. In 7 to 15 per cent of the patients with bone metastasis normal levels of serum prostatic acid phosphatase were found. Variability in prostatic acid phosphatase production by the tumor may account for this finding. Elevated levels of prostatic acid phosphatase were associated more commonly with less differentiated primary tumors. A low percentage of prostatic acid phosphatase elevations in patients with early localized and incidental adenocarcinoma was found for the 3 assays evaluated. These factors, along with the falsely positive rates in patients with benign disease, limit severely the application of these assays to the screening of male patients at risk for adenocarcinoma of the prostate.