[Mass screening for prostate cancer in Japan].

Since 1975 mass screening for prostate cancer has been performed in Japan. The Prostate Research Foundation has analysed the data every year that collected from all institutes performing a mass screening. Up to 1993, 67, 225 subjects were examined. The detection rate of prostate cancer was 0.69%. Approximately half of the cancer were stage B, and the subjects who have metastatic stage were only 20% and the pattern of stage seemed to be different from that of patients who visited hospitals. In Chiba prefecture the subjects lived in a district of south Boso peninsula received a mass screening for prostate cancer with total of 1,964 men from 1985, and 17 cancers were diagnosed (0.87%). The distribution of prostate-specific antigen (PSA) assayed with Tandem-R kit was examined using the stocked sera (n = 976) of the screening for prostate cancer in Chiba prefecture. The percentage of 0.05-4.0 ng/ml, 4.1-9.9 ng/ml, over than 10.0 ng/ml of the PSA, were 89.6%, 7.0%, 3.4%, respectively. This distribution is approximately as same as the previous reports by the United States and Canada.