[A mass screening of the prostatic diseases and serum prostate specific antigen].

We examined the values of prostate specific antigen (PSA) with a RIA kit (Pros Check PSA) and an EIA kit (Market F PA), measuring prostate weights of 125 participants in a mass screening of the prostatic diseases. A mild positive correlation (r = 0.467) between values of PSA (RIA) and prostate weights was found in the participants in whom the prostate cancer was not detected. Since serum PSA levels measured by RIA of 45 normal subjects were 1.8 +/- 1.5 ng/ml (Mean +/- S.D), the upper limit of the normal range was set at 6.3 ng/ml. The participants whose PSA levels exceeded this upper normal range and also whose prostate weights were under 30 g were found in 11 of the 122 subjects (9%). On the contrary, the abnormal values (EIA) were found in only two subjects (one, a prostate cancer and the other, a benign prostate hypertrophy). We, further, examined the PSA values (EIA) in 415 subjects in whom the prostate cancer was detected in 5 (1.2%). The abnormal values were found in 8 (4 prostate cancer, 3 benign prostate hypertrophy and one without prostatic disease). As the false positive rate was very low, the use of PSA is recommended in the first screening of the check up program of the prostatic disease.