Durable efficacy of adjuvant radiation therapy for prostate cancer: will the benefit last?

Radical prostatectomy can be an effective therapy for men with organ-confined disease. However, extension beyond the confines of the prostate (pT3) can be found in many men, and this is often associated with longterm prostate-specific antigen (PSA) failure. Not all patients will progress with pT3 disease. The identification of additional adverse prognostic features (high Gleason score, PSA greater than 10 ng/mL, and seminal vesical invasion) can help identify those men at highest risk of progression following definitive surgery. The role of postoperative therapy in patients with high-risk features is often controversial. The lack of long-term survival benefit, toxicity, and cost are often cited. We reviewed our experience with a unified approach to this patient population and performed matched-pair analysis of patients with similar adverse prognostic features treated with and without postoperative radiation therapy. For our series, the results indicate that the addition of adjuvant radiation therapy is associated with a significantly reduced risk of PSA recurrence. The 5-year bNED rate after adjuvant radiation therapy was 89% (95% CI: 76% to 100%) compared with 55% (95% CI: 34% to 79%) after surgery alone (P = .002). This benefit also appears to hold true for men with pathological involvement of their seminal vesicles. A dose-response curve was observed with improved disease control above a level of 61.2 Gy. Appropriate patient selection and delivery of an adequate dose of radiation can improve the PSA recurrence of most patients with pT3 disease.