Clinical value of different methods for determination of acid phosphatase in prostatic cancer

The availability of a radioimmunoassay (RIA) and an enzyme immunoassay (EIA) for the prostate specific acid phosphatase required a study to compare these techniques with the conventional colorimetric assay. Our study is based on examinations of 188 normal persons and 136 patients with carcinoma of the prostate. The advantage of the immunologic methods - RIA and EIA - lies in their stable immunologic activity and their high specificity. However, RIA and EIA are not screening methods for incidental carcinoma because of their low sensitivity for stage-A tumors. Their good sensitivity at lower ranges of concentration makes them suitable for checking the course of a prostatic carcinoma during therapy. The level of prostatic acid phosphatase may allow conclusions about intra-or extracapsular growth of the prostatic carcinoma.