Prostate-specific antigen-based population screening for prostate cancer: current status in Japan and future perspective in Asia

Abstract

In Western countries, clinical trials on prostate cancer screening demonstrated a limited benefit for patient survival. In the Asia-Pacific region, including Japan, the rate of prostate-specific antigen (PSA) testing remains very low compared with Western countries, and the benefits of population-based screening remain unclear. This review describes the current status of population screening and diagnosis for prostate cancer in Japan and discusses the efficacy of population screening for the Asian population. Since the 1990s, screening systems have been administered by each municipal government in Japan, and decreases in the prostate cancer mortality rate are expected in some regions where the exposure rate to PSA screening has increased markedly. A population-based screening cohort revealed that the proportion of metastatic disease in cancer detected by screening gradually decreased according to the increased exposure rate, and a decreasing trend in the proportion of cancer with high serum PSA levels after population screening was started. The prognosis of the prostate cancer detected by population screening was demonstrated to be more favorable than those diagnosed outside of the population screening. Recent results in screening cohorts demonstrated the efficacy of PSA. These recent evidences regarding population-based screening in Japan may contribute to establishing the optimal prostate cancer screening system in Asian individuals.

Figure 1

Screening systems for prostate cancer in Japan.

Figure 2

Kaplan–Meier plots of the cause-specific survival rates of prostate cancer patients detected by prostate-specific antigen-based population screening in Kanazawa city (modified from Reference19).

Figure 3

Cumulative probabilities of developing prostate cancer during follow-up in the participants with baseline prostate-specific antigen levels of 2.0 ng ml⁻¹ or lower (modified from Reference54).

Figure 4

Cumulative probabilities of prostate cancer detection according to free to total prostate-specific antigen (PSA) ratio during follow-up in participants with baseline PSA levels of 2.1–10.0 ng ml⁻¹ (modified from Reference65).