A significant proportion of men that experience biochemical recurrence after radical prostatectomy do not receive timely salvage radiation therapy (sRT). It is unknown whether use of concomitant anti-androgen therapy (AAT) in such men has a beneficial effect on survival or not. We sought to examine whether the addition of AAT to late sRT can lead to oncological outcomes similar to that of early sRT alone, in men with recurrent prostate cancer after radical prostatectomy.
Data on 670 men who participated in the RTOG-9601 trial and experienced biochemical recurrence were extracted (Figure 1). Patients were stratified into four treatment groups: early sRT (pre-sRT PSA <0.7 ng/mL) with/without concomitant AAT and late sRT (pre-sRT PSA >=0.7 ng/mL) with/without concomitant AAT, based on the cut-offs reported in the original trial. Time-varying Cox proportional hazards and Fine-Gray competing-risk regression analyses assessed the adjusted hazards of overall mortality, CaP specific mortality and metastatic/local disease progression among the four treatment groups. A p-value <0.05 was considered significant.
Patients were well-matched in baseline characteristics. The median follow-up was 14.7 years. At 15 years, for patients treated with early sRT, early sRT with AAT, late sRT and late sRT with AAT, the overall mortality, CaP specific mortality and metastasis rates were 22.9%, 22.8%, 40.1% and 22.9% (Log-rank p=0.0039), 12.1%, 3.9%, 22.7% and 8.0% (Gray’s p=0.0004) and 18.8%, 14.6%, 35.9% and 19.5% (Gray’s p=0.0004), respectively (Figure 2). Time-varying adjusted analysis demonstrated increased hazards of overall mortality in patients receiving delayed sRT versus early sRT, HR 1.49 (95% CI: 1.02 - 2.17). However, no difference remained after addition of concomitant AAT to late sRT, HR 0.85 (95% CI: 0.55 - 1.32, referent early sRT). Similarly, the hazards of cancer-specific mortality and metastatic progression were worse for late sRT, when compared to early sRT, but were no different after addition of AAT to late sRT.
Poorer outcomes associated with late-sRT in men with recurrent CaP may be rescued by delivery of concomitant AAT.
Image(s) (click to enlarge):
ANTI-ANDROGEN THERAPY OVERCOMES THE TIME-DELAY IN INITIATION OF SALVAGE RADIATION THERAPY AND RESCUES ONCOLOGICAL OUTCOMES IN MEN WITH RECURRENT PROSTATE CANCER AFTER RADICAL PROSTATECTOMY
Prostate Cancer > Locally Advanced
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Thursday, Dec 2
4:00 p.m. - 5:00 p.m.
Presented By: Akshay Sood
Craig G Rogers
James O Peabody