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.