Clinical significance of prostate specific antigen for early stage prostate cancer detection.

The characteristics of serum prostate specific antigen (PSA) in normal Japanese men were studied in 1480 subjects examined by mass screening (MS) for prostate cancer (Pca) in Gunma Prefecture in 1992. The serum PSA concentration was correlated with patient age. The average serum PSA level increased by 0.04 ng/ml/year. The upper normal limits (95 percentiles) of age specific PSA for normal men are 1.33 ng/ml for those aged 39-49 years, 3.65 ng/ml for those aged 50-59 years, 4.06 ng/ml for those aged 60-69 years, 5.09 ng/ml for those aged 70-79 years and 5.66 ng/ml for those aged 80-89 years. Among 227 normal men examined by our MS in 1991 and 1992, the PSA velocity (PSAV) was calculated to be 0.05 ng/ml/year. Among 10 Pca patients with normal PSA levels (< 6 ng/ml) detected previously by our MS, three had an abnormal PSAV. We demonstrated the possibility that PSA density could distinguish between Pca and benign prostate hypertrophy. The significance of PSA as a Pca screening modality should be evaluated across multiple age ranges and in combination with previous PSA data and/or prostate volume estimated by sonography.