Active surveillance in men with intermediate-risk prostate cancer
Jonathan Suderman1, Walid Eshumani1, Ali Hussein1, Alan I. So1, Martin E. Gleave1, Sheldon Goldenberg1, Peter C. Black1.
1Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada
Introduction: Active surveillance (AS) is well-established for the management of low- and very low-risk prostate cancer (PCa). Intermediate-risk PCa (IRPCa) represents a broad spectrum of disease biologically, and criteria to determine which patients are suitable for AS have not been established. Our objective was to identify predictors of disease progression in men with IRPCa.
Methods: Clinical data were collected from men diagnosed with PCa from 1993–2021 who were monitored on an AS protocol at the Vancouver Prostate Centre. A subject was considered on AS if a confirmatory biopsy was performed after an initial diagnosis of PCa. Men were classified into risk categories according to the National Comprehensive Cancer Network (NCCN) and Cancer of the Prostate Risk Assessment (CAPRA) scores. The primary endpoint was progression to definitive treatment (“intervention”), compared between risk groups.
Results: Analysis was performed on 1113 patients, including 291 (26.1%) with IRPCa, of whom 212 (72.9%) had favorable and 79 (27.1%) had unfavorable IRPCa. Median followup was 9.2 years (interquartile range 5.8). Intervention rates at five and 10 years were 36.7% (302/822) and 48.9% (402/822) for NCCN low-risk PCa and 45.7% (133/291) and 56.7% (165/291) for NCCN IRPCa, respectively. Intervention rates at five and 10 years were no different for CAPRA low and IRPCa. Favorable and unfavorable IRPCa intervention rates at five years were 41.4% (88/212) and 57.0% (45/79), respectively (hazard ratio [HR] 1.38, 95% confidence interval [CI] 0.96–1.98), and at 10 years were 52.8% (112/212) and 67.1% (53/79), respectively (HR1.27, 95% CI 0.95–1.70). Kaplan-Meier curves for men remaining on AS with favorable and unfavorable PCa are shown in Figure 1.
Conclusions: There was no observed difference in five- and 10-year intervention rates between men with low-risk vs. IRPCa, and unfavorable vs. favorable IRPCa. Multivariable analysis is ongoing to assess risk factors that predict need for definitive local therapy, which will help identify IRPCa patients most suitable for AS.
