Postoperative adjuvant and salvage radiotherapy for prostate cancer: Impact on freedom from biochemical relapse and survival

Objectives. To determine the therapeutic outcomes in patients with high-risk prostate cancer treated with adjuvant or salvage radiotherapy (RT) after radical prostatectomy. Methods. Between 1982 and 2000, 163 patients were treated with RT after radical prostatectomy. Adjuvant therapy was administered to 107 consecutive node-negative patients (T2-T4N0) referred to our institution less than 1 year after surgery for postoperative RT. Salvage treatment was delivered to 56 patients for a persistently elevated prostate-specific antigen level, biochemical relapse after surgery, or local recurrence. Results. The median follow-up was 70 months (range 2 to 167) from the initiation of RT. Patients treated with adjuvant RT were less likely than those treated with salvage RT to experience biochemical relapse. At 5 and 10 years, the rate of freedom from biochemical relapse was 80% and 66% in the adjuvant cohort compared with 39% and 22% for patients treated with salvage intent, respectively (P <0.0001). This did not translate into a statistically significant improvement in absolute survival (72% versus 70%) or cause-specific survival (93% versus 86%) at 10 years. On multivariate analysis, neoadjuvant hormonal therapy (P = 0.0187), presence of seminal vesicle involvement (P = 0.0002), and referral indication for postoperative RT (salvage versus adjuvant RT; P <0.001) were predictors of biochemical relapse. Conclusions. In this single-institution experience, patients at high risk of disease recurrence after radical prostatectomy realized a greater biochemical relapse-free survival benefit when treated with adjuvant RT than with salvage RT. Neoadjuvant hormonal therapy and seminal vesicle involvement predicted for inferior treatment outcome.