Salvage Radiotherapy Versus Hormone Therapy for Prostate-specific Antigen Failure After Radical Prostatectomy: A Randomised, Multicentre, Open-label, Phase 3 Trial (JCOG0401)†.

No standard therapy has been established for localised prostate cancer patients with prostate-specific antigen (PSA) failure after radical prostatectomy (RP). To determine whether radiotherapy ± hormone therapy is superior to hormone therapy alone in such patients. This study is a multicentre, randomised, open-label, phase 3 trial. Patients with localised prostate cancer whose PSA concentrations had decreased to <0.1 ng/ml after RP, and then increased to 0.4–1.0 ng/ml, were randomised to the salvage hormone therapy (SHT) group (80 mg bicalutamide [BCL] followed by luteinising hormone-releasing hormone agonist in case of BCL failure) or the salvage radiation therapy (SRT) ± SHT group (64.8 Gy of SRT followed by the same regimen as in the SHT group in case of SRT failure). From May 2004 to May 2011, 210 patients (105 in each arm) were registered, with the median follow-up being 5.5 yr. The primary endpoint was time to treatment failure (TTF) of BCL. TTF of BCL was significantly longer in the SRT ± SHT group (8.6 yr) than in the SHT group (5.6 yr; hazard ratio 0.56, 90% confidence interval [0.40–0.77]; one-sided p = 0.001). Thirty-two of 102 patients (31%) in the SRT ± SHT group did not have SRT treatment failure. However, clinical relapse-free survival and overall survival did not differ between the arms. The most frequent grade 3–4 adverse event was erectile dysfunction (83 patients [80%] in the SHT group vs. 76 [74%] in the SRT ± SHT group). Limitations include the short follow-up periods and surrogate endpoint setting to allow definitive conclusions. Initial SRT prolongs TTF of BCL in patients with post-RP PSA failure, indicating that SRT ± SHT is more beneficial than SHT alone. Patients who have prostate-specific antigen failure after radical prostatectomy benefit from salvage radiation therapy prior to salvage hormone therapy. [ABSTRACT FROM AUTHOR]