European Association of Urology Biochemical Recurrence Risk Classification as a Decision Tool for Salvage Radiotherapy-A Multicenter Study

Background: The European Association of Urology (EAU) has proposed a risk stratification for patients harboring biochemical recurrence (BCR) after radical prostatectomy (RP). Objective: To assess whether this risk stratification helps in choosing patients for salvage radiotherapy (SRT). Design, setting, and participants: Analyses of 2379 patients who developed BCR after RP (1989-2020), within ten European high-volume centers, were conducted. Early and late SRT were defined as SRT delivered at prostate-specific antigen values <0.5 and ≥0.5 ng/ml, respectively. Outcome measurements and statistical analysis: Multivariable Cox models tested the effect of SRT versus no SRT on death and cancer-specific death. The Simon-Makuch method tested for survival differences within each risk group. Results and limitations: Overall, 805 and 1574 patients were classified as having EAU low- and high-risk BCR. The median follow-up was 54 mo after BCR for survivors. For low-risk BCR, 12-yr overall survival was 87% versus 78% (p = 0.2) and cancer-specific survival was 100% versus 96% (p = 0.2) for early versus no SRT. For high-risk BCR, 12-yr overall survival was 81% versus 66% (p < 0.001) and cancer-specific survival was 98% versus 82% (p < 0.001) for early versus no SRT. In multivariable analyses, early SRT decreased the risk for death (hazard ratio [HR]: 0.55, p < 0.01) and cancer-specific death (HR: 0.08, p < 0.001). Late SRT was a predictor of cancer-specific death (HR: 0.17, p < 0.01) but not death (p = 0.1). Conclusions: Improved survival was recorded within the high-risk BCR group for patients treated with early SRT compared with those under observation. Our results suggest recommending early SRT for high-risk BCR men. Conversely, surveillance might be suitable for low-risk BCR, since only nine patients with low-risk BCR died from prostate cancer during follow-up. Patient summary: The impact of salvage radiotherapy (SRT) on cancer-specific outcomes stratified according to the European Association of Urology biochemical recurrence (BCR) risk classification was assessed. While men with high-risk BCR should be offered SRT, surveillance might be a suitable option for those with low-risk BCR.