The long-term outcomes of Gleason grade groups 2 and 3 prostate cancer managed by active surveillance: Results from a large population-based cohort

INTRODUCTION: Active surveillance (AS) is an accepted management strategy for low-risk prostate cancer (PCa), but its role in the management of favorable intermediate-risk PCa remains controversial. Most reports studying the role of AS for these men generally lack long-term followup and include small numbers of patients. Our objective was to report the outcomes of men diagnosed with Gleason grade groups (GGG) 2 and 3 PCa who were managed expectantly. METHODS: Using administrative datasets and pathology reports, we identified all men who were diagnosed with GGG 2 and 3 PCa and managed expectantly between 2002 and 2011 in Ontario, Canada. Outcomes and associated factors were estimated using cumulative incidence function methods and multivariable Cox regression models, respectively. RESULTS: We identified 926 men who were managed expectantly (AS [n=374] or watchful waiting [n=552]). The eight-year cancer-specific survival was 94% and 89% for the AS and watchful waiting cohorts, respectively. Among AS men, 266 (71%) received treatment after a followup of approximately eight years. Cumulative AS discontinuation rates at one and five years were 30.5% and 65.1%, respectively. CONCLUSIONS: Expectant management of GGG 2 and 3 PCa may be an option for certain men. Notably for AS patients, the cancer-specific mortality at eight years was 6%, and over 65% of men underwent treatment within five years. Further studies are required to evaluate which patients, based on disease-specific features and competing health risks, would benefit most from a conservative strategy.