Temporal changes in the urologist's practice behaviour of active surveillance for prostate cancer: analysis of prospective observational study cohort.

[BACKGROUND] To analyse temporal trends and variations in the use of active surveillance (AS) for low- and intermediate-risk prostate cancer in Japan.

[METHODS] We conducted a retrospective analysis of data from the Prostate Cancer Research International: AS-JAPAN study, a multi-institutional prospective observational cohort study, collected between January 2010 and February 2024. The primary outcomes of interest were temporal trends in characteristics of patients undergoing AS, including risk classification, age at enrollment, patterns of treatment interventions during AS, and reasons for discontinuation of AS.

[RESULTS] A total of 1263 patients were included, with a median follow-up period of 30 months (interquartile range: 11-59). The proportion of patients with D'Amico intermediate-risk prostate cancer significantly increased over time (R2 = 0.7139), reaching 24.7% in 2023. No significant trend was observed for younger patients aged ≤60 years, but the proportion of patients aged ≥75 years increased over time (R2 = 0.5133). Among treatment interventions during AS, no significant trends were noted in the use of prostatectomy, external beam radiation therapy, hormone therapy, or watchful waiting; however, the use of brachytherapy significantly decreased (R2 = 0.5604). Reasons for discontinuing AS revealed a slight increase in off-protocol cases over time, reaching 59.6% in 2023 (R2 = 0.3869).

[CONCLUSION] These findings highlight a notable shift in the adoption of AS in Japan, with an increasing proportion of intermediate-risk and older patients. The rise in off protocol AS discontinuation underscores the complexities of clinical decision-making in the context of AS.