Health-related quality of life in Japanese low-risk prostate cancer patients choosing active surveillance: 3-year follow-up from PRIAS-JAPAN.

PURPOSE To evaluate the health-related quality of life (HRQoL) of Japanese men on active surveillance (AS) in the Prostate cancer Research International Active Surveillance study in Japan (PRIAS-JAPAN). METHODS Participants were included in the PRIAS-JAPAN HRQoL study between January 2010 and March 2016. Their general HRQoL was assessed using a validated Japanese version of the Short-Form 8 Health Survey (SF-8) at enrolment and annually thereafter until discontinuation of AS. The SF-8 mental component summary (MCS) and physical component summary (PCS) of men on AS were compared with scores of the general population (norm-based score [NBS]: 50) and MCS and PCS scores for men following AS were analysed over time. We tested whether MCS and PCS scores over time explained discontinuation of AS. RESULTS Five hundred and twenty-five patients enrolled, and the median age at baseline was 68 years. At enrolment and after 1-, 2-, and 3-year follow-ups, the PCS and MCS scores were significantly higher than the NBS of the general Japanese population except for the median PCS at 3 years. We found that age at diagnosis and time on AS negatively affected the PCS score of men on AS, while every additional year on AS led to a 0.27 point increase in MCS scores. Neither PCS nor MCS were predictors for discontinuation of AS. CONCLUSION Japanese men following an AS strategy for 3 years reported better HRQoL compared with the general population, indicating that monitoring Japanese low-risk prostate cancer patients can be an effective treatment strategy. STUDY REGISTRATION Clinical trial registry-UMIN (University Hospital Medical Information Network); UMIN000002874 (2009/12/11).