AbstractBackgrounds and objectives
In Japan, two prospective multicenter active surveillance (AS) studies are under investigation. The first is a prospective Japanese AS study that has been carried out in favorable risk prostate cancer since 2002. The second is the PRIAS-JAPAN; 30 institutions in Japan have been participating into the Prostate cancer Research International: Active Surveillance (PRIAS) study as the PRIAS-JAPAN since 2010.The objective of this study is to evaluate the outcomes of 1 year after AS including prostate re-biopsy and the change in QOL status using the two Japanese prospective cohorts.Patients and methods
Thirteen institutions participated in the Japanese AS study. One hundred and thirty-four patients with biopsy proven favorable risk prostate cancer were enrolled into study between January 2002 and December 2003. AS remaining rate in 33.2%. On the other hand, the PRIAS-JAPAN study was started since January 2010. Until December 2011, 189 patients were enrolled. One year after rebiopsy was recommended to all participants, and QOL was assessed at enrollment and at 1 year after AS in both studies.Results
In the Japanese AS study, 64 patients who underwent re-biopsy, 42 met the pathological selection criteria again. The reclassification rate was 34.4%. In PRIAS-JAPAN, the reclassification rate was 28% (P = 0.467). There was no predictive parameter for reclassification in the Japanese AS study. On the other hand, number of positive cores was a significant predictive parameter for reclassification in PRIAS-Japan. Almost all domains of QOL at enrollment revealed better QOL than norm-based scoring (NBS). At 1 year after AS, there was no significant change.Conclusions
Instead of the time difference between the two studies was ∼10 years, the reclassification rate for the current AS cohort (PRIAS-J) was comparable or even lower than the former cohort. Health-related QOL of the Japanese patients who opted AS as an initial treatment was better than NBS and it has been maintained 1 year after AS.