Active surveillance with selective delayed intervention for favorable risk prostate cancer: clinical experience and a 'number needed to treat' analysis.

This is a summary of the case for active surveillance for 'favorable-risk' prostate cancer with selective delayed intervention for rapid biochemical progression, assessed by rising prostate-specific antigen (PSA) levels, or grade progression. The results of a large phase II trial using this approach are reviewed. To date, this study has shown that virtually all men with 'favorable-risk' prostate cancer managed in this fashion will die of unrelated causes. Based on the Swedish randomized trial of radical prostatectomy versus watchful waiting, the Connecticut observation series, and the Toronto active surveillance experience, a number needed to treat analysis of the benefit of radical treatment of all newly diagnosed favorable risk prostate cancer patients, compared to a strategy of active surveillance with selective delayed intervention, is presented. This suggests that approximately 100 patients will require radical treatment for each prostate cancer death averted. This translates into a 2-3 week survival benefit, unadjusted for quality of life. This figure is confirmed based on an analysis of the D'Amico PSA velocity data in favorable risk disease. The approach of active surveillance with selective delayed intervention based on PSADT and repeat biopsy represents a practical compromise between radical therapy for all patients, (which results in overtreatment for patients with indolent disease), and watchful waiting with palliative therapy only, (which results in undertreatment for those with aggressive disease).