Clinical results of long-term follow-up of a large, active surveillance cohort with localized prostate cancer

Abstract

PURPOSE We assessed the outcome of a watchful-waiting protocol with selective delayed intervention by using clinical prostate-specific antigen (PSA), or histologic progression as treatment indications for clinically localized prostate cancer. PATIENTS AND METHODS This was a prospective, single-arm, cohort study. Patients were managed with an initial expectant approach. Definitive intervention was offered to those patients with a PSA doubling time of less than 3 years, Gleason score progression (to 4 + 3 or greater), or unequivocal clinical progression. Survival analysis and Cox proportional hazard model were applied to the data. Results A total of 450 patients have been observed with active surveillance. Median follow-up was 6.8 years (range, 1 to 13 years). Overall survival was 78.6%. The 10-year prostate cancer actuarial survival was 97.2%. Overall, 30% of patients have been reclassified as higher risk and have been offered definitive therapy. Of 117 patients treated radically, the PSA failure rate was 50%, which was 13% of the total cohort. PSA doubling time of 3 years or less was associated with an 8.5-times higher risk of biochemical failure after definitive treatment compared with a doubling time of more than 3 years (P < .0001). The hazard ratio for nonprostate cancer to prostate cancer mortality was 18.6 at 10 years. CONCLUSION We observed a low rate of prostate cancer mortality. Among the patients who were reclassified as higher risk and who were treated, PSA failure was relatively common. Other-cause mortality accounted for almost all of the deaths. Additional studies are warranted to improve the identification of patients who harbor more aggressive disease despite favorable clinical parameters at diagnosis.