Adjuvant radiotherapy following radical prostatectomy for pathologic T3 or margin-positive prostate cancer: A systematic review and meta-analysis

BACKGROUND AND PURPOSE: Results following radical prostatectomy (RP) are suboptimal in patients found to have cancer extending beyond the prostatic capsule (pT3) or present at the resection margins (R1). The optimal postoperative management of such patients is undefined. Therapeutic alternatives include adjuvant radiotherapy (RT) or active surveillance. METHODS: Randomized controlled trials (RCTs) were eligible for inclusion in this systematic review if they compared adjuvant RT in the immediate period after RP to active surveillance - with therapies held in reserve for salvage - in prostate cancer patients with pT3 or R1 disease or both. The primary outcome of interest was overall survival. RESULTS: Three RCTs representing 1,743 patients satisfied the eligibility criteria. Two trials reported data on overall survival; a meta-analysis of the data showed no significant improvement associated with adjuvant RT (hazard ratio=0.91, 95% CI 0.67-1.22, p=0.52). All trials reported data on biochemical progression-free survival (bPFS). On meta-analysis, adjuvant RT significantly improved bPFS (hazard ratio=0.47, 95% CI 0.40-0.56, p<0.00001). One trial provided comparative graded toxicity data; there were no significant differences between arms in severe (grade 3) gastrointestinal or genitourinary toxicity at five years. CONCLUSIONS: To date, adjuvant RT has not been shown to improve overall survival compared with active surveillance. Longer follow-up from completed RCTs is required to accurately assess this outcome. Adjuvant RT does, however, significantly improve bPFS and is not associated with excess severe late toxicity.