Decreasing trend in prostate cancer with high serum prostate-specific antigen levels detected at first prostate-specific antigen-based population screening in Japan

To clarify the recent trends in prostate-specific antigen (PSA) distribution in men in Japan, we analyzed the PSA distributions of men undergoing PSA-based population screening. We summarized the annual individual data of PSA-based population screening in Kanazawa, Japan, from 2000 to 2011, and analyzed baseline serum PSA values of the participants at the first population screening. Serum PSA distributions were estimated in all participants and those excluding prostate cancer patients according to age. From 2000 to 2011, 19 620 men participated aged 54–69 years old in this screening program. Mean baseline serum PSA level of all participants at the first screening was 2.64 ng ml(−1) in 2000, and gradually decreased to approximately 1.30 ng ml(−1) in 2006. That of participants excluding prostate cancer patients was 1.46 ng ml(−1) in 2000, and there was no remarkable change during the study period. The 95(th) percentiles in the participants excluding prostate cancer patients detected at the first population screening of men aged 54–59, 60–64, and 65–69 years old were 2.90, 3.60, and 4.50 ng ml(−1), respectively. After the commencement of population screening, the proportion of prostate cancer patients with high serum PSA levels decreased. However, there were no changes in serum PSA levels in men without prostate cancer. Age-specific PSA reference level of men without prostate cancer in Japan was similar to that in China and Korea.