The efficacy of early adjuvant radiation therapy for pT3N0 prostate cancer: A matched-pair analysis

Purpose: This study examines the effect of adjuvant radiation therapy (RT) on outcome in patients with pT3N0 prostate cancer and makes comparisons to a matched control group, Methods and Materials: At our center, 149 patients undergoing radical prost atectomy were found to hare pT3N0 prostate cancer, had an undetectable post operative prostate-specific antigen (PSA) level, and had no immediate hormo nal therapy. Fifty-two patients received adjuvant RT within 3 to 6 months o f surgery, Ninety-seven underwent radical prostatectomy alone and were obse rved until PSA failure. From these two cohorts, me matched patients 1:1 acc ording to preoperative PSA (<10 ng/ml vs. >10 ng/ml), Gleason score (<7 vs. greater than or equal to 7), seminal vesicle invasion, and surgical margin status. Seventy-two patients (36 pairs) were included in the analysis. Med ian follow-up time was 41 months. We calculated a matched-pairs risk ratio for cumulative risk of PSA relapse (a rise above 0.2 ng/ml), Results: After controlling for the prognostic factors by matching, there wa s an 88% reduction (95% confidence interval [CI]: 78-93%) in the risk of PS A relapse associated with adjuvant RT, The 5-year freedom from PSA relapse rate was 89% (95% CI: 76-100%) for patients receiving adjuvant RT as compar ed to 55% (95% CI: 34-79%) for those undergoing radical prostatectomy alone , Conclusions: These data suggest that adjuvant RT for pT3N0 prostate cancer mag significantly reduce the risk of PSA failure as compared to radical pro statectomy alone. Its effect on clinical outcome awaits further follow-up, (C) 1999 Elsevier Science Inc.