Stage-Specific Temporal Trends in Treatment Patterns and Overall Survival in Prostate Cancer: A Multicentre Real-World Cohort Study From KAMU-ON.

OBJECTIVES: To evaluate stage-specific temporal trends in treatment patterns and overall survival (OS) among patients with prostate cancer in a Japanese multicentre cohort. METHODS: This multicentre retrospective cohort study used data from the Kaga Million Uro-Oncology Network (KAMU-ON) registry. Patients diagnosed with prostate cancer between 2010 and 2024 were categorized as localized, nonmetastatic advanced, or metastatic disease. OS was assessed using Kaplan-Meier analyses and multivariable Cox proportional hazards models adjusted for clinically relevant covariates. Additional analyses with follow-up administratively restricted at 48 months were performed. RESULTS: A total of 7140 patients with defined disease stage and available survival data were included, comprising 5048 patients with localized disease, 1128 with nonmetastatic advanced disease, and 964 with metastatic disease. Treatment patterns changed substantially across diagnostic eras. Survival improvement appeared most evident in metastatic disease, whereas temporal differences were less apparent in nonmetastatic advanced disease. In multivariable Cox analyses, later diagnostic eras were associated with lower hazards of death in the overall cohort (2014-2017: HR 0.90, 95% CI 0.76-1.08; 2018-2024: HR 0.79, 95% CI 0.64-0.98). Formal interaction testing did not demonstrate statistically significant effect modification according to disease stage (p = 0.163). CONCLUSIONS: Temporal survival trends in prostate cancer appeared to vary across disease stages in this Japanese multicentre cohort. Survival improvement appeared most evident in metastatic disease, whereas changes were less pronounced in nonmetastatic advanced disease. These findings suggest that therapeutic advances may not uniformly translate into survival gains across prostate cancer disease states.