Postoperative radiotherapy after radical prostatectomy for high-risk prostate cancer: long-term results of a randomised controlled trial (EORTC trial 22911)

Background We report the long-term results of a trial of immediate postoperative irradiation versus a wait-and-see policy in patients with prostate cancer extending beyond the prostate, to confirm whether previously reported progression-free survival was sustained. Methods This randomised, phase 3, controlled trial recruited patients aged 75 years or younger with untreated cT0-3 prostate cancer (WHO performance status 0 or 1) from 37 institutions across Europe. Eligible patients were randomly assigned centrally (1:1) to postoperative irradiation (60 Gy of conventional irradiation to the surgical bed for 6 weeks) or to a wait-and-see policy until biochemical progression (increase in prostate-specific antigen >0.2 mu g/L confirmed twice at least 2 weeks apart). We analysed the primary endpoint, biochemical progression-free survival, by intention to treat (two-sided test for difference at alpha=0.05, adjusted for one interim analysis) and did exploratory analyses of heterogeneity of effect. This trial is registered with ClinicalTrials.gov, number NCT00002511. Findings 1005 patients were randomly assigned to a wait-and-see policy (n=503) or postoperative irradiation (n=502) and were followed up for a median of 10.6 years (range 2 months to 16.6 years). Postoperative irradiation significantly improved biochemical progression-free survival compared with the wait-and-see policy (198 [39.4%] of 502 patients in postoperative irradiation group vs 311 [61.8%] of 503 patients in wait-and-see group had biochemical or clinical progression or died; HR 0.49 [95% CI 0.41-0.59]; p