PD08-03 EAU BCR RISK CLASSIFICATION AS DECISION TOOL FOR SALVAGE RADIOTHERAPY? A MULTICENTER STUDY
Abstract
INTRODUCTION AND OBJECTIVE:
Recently, a new prognostic model for patients harboring biochemical recurrence (BCR) after radical prostatectomy (RP) has been proposed by the European Association of Urology (EAU): EAU low-risk BCR (Gleason score <8 and prostate specific antigen doubling time (PSADT) >12months) vs. EAU high-risk BCR (Gleason score ≥8 or PSADT <=12months). However, whether this risk stratification may help choosing patients for salvage radiotherapy (SRT) remains unclear.
METHODS:
Retrospective analyses of 2473 RP patients who developed BCR and were treated between 1989 and 2020 (1121 with SRT and 1352 without SRT) within nine European institutional high-volume centers. Patients with adjuvant radiotherapy (RT) or lymph node invasion were excluded. Early SRT was defined as SRT delivered at PSA values <0.5ng/ml, late SRT was defined as SRT delivered at PSA values >=0.5ng/ml. Kaplan-Meier curves as well as multivariable Cox-regression analyses, adjusted for pathologic stage, age at RP, year of surgery and persistence PSA after RP, tested the effect of early SRT vs. late SRT vs. no RT on metastatic progression, death and cancer-specific death within each risk group.
RESULTS:
Overall, 805 patients were classified as EAU low- and 1574 patients EAU high-risk BCR, respectively. Median follow-up was 84.4 months (interquartile range: 48.4-129 months). For low-risk BCR patients, 12-yr overall and cancer-specific survival rates were 92.0 vs. 92.6 vs. 89.0% (p=0.1) and 100.0 vs. 100.0 vs. 97.6% (p=0.1) for early SRT vs. late SRT vs. no RT patients. For high-risk BCR patients, 12-yr overall and cancer-specific survival rates were 84.7 vs. 81.8 vs. 76.0% (p <0.01) and 95.1 vs. 94.2 vs. 82.7% (p <0.001) for early SRT vs. late SRT vs. no RT patients. In multivariable analyses, early SRT compared to no SRT decreased the risk for metastatic disease (HR: 0.41, p <0.001), death (HR: 0.67, p=0.04) and cancer specific death (HR: 0.27, p <0.001) only within the EAU high-risk BCR group. In patients classified as EAU low-risk BCR SRT compared to surveillance only was not decreasing the risk to metastatic disease, death or cancer specific death.
CONCLUSIONS:
Our data suggests that early SRT compared to no SRT improves cancer specific outcomes in men classified as EAU high-risk BCR. In contrast, in men classified as EAU low-risk BCR we were not able to show that early or late SRT improve cancer specific outcomes. These results suggest to recommend early SRT in men with EAU high-risk BCR. Conversely, surveillance only might be a suitable option for men classified as EAU low-risk BCR.
Source of Funding:
None
