Active Surveillance in Prostate Cancer With Intermediate-Risk Features: The PRIAS-JAPAN Study.

Objectives: To report outcomes of active surveillance (AS) for prostate cancer in men with intermediate-risk features of International Society of Urological Pathology (ISUP) grade group 2 and/or clinical stage T2 compared with ISUP grade group 1 and clinical stage T1 in the PRIAS-JAPAN study.

Methods: Patients with prostate cancer diagnosed between January 2010 and February 2024 were included in this study. PSA test, rectal examination, and re-biopsy were performed regularly. We calculated the pathological reclassification rate, program persistence rate, and subsequent treatment.

Results: Data from 1302 participants were collected. After excluding patients who did not fit inclusion criteria (n = 28) or follow-up of less than 1 year (n = 208), 1066 patients were included in this analysis. The median follow-up was 42.4 months (interquartile range 17.0-72.1). There were no statistical differences in the pathological reclassification, persistence rates, and subsequent therapy between low- and intermediate-risk features.

Conclusion: This preliminary study demonstrated medium-term outcomes of AS in prostate cancer with intermediate-risk features in Japan, suggesting no significant difference in the pathological reclassification, persistence rate, and subsequent therapy between low- and intermediate-risk features.