Researchers at Duke University observed a survival benefit for men who had salvage radiation therapy (RT) for prostate-specific antigen (PSA) failure after radical prostatectomy (RP) in the men who experience a rapid rises in PSA doubling time (DT,< 6 months). They then asked whether such a benefit also exits in men with a protracted PSA rise in DT (?6 months).They sampled 4036 men who underwent a RP at Duke University between 1988 and 2008. They found that 519 experienced a PSA failure, their files had complete data. These men were included as subjects of their study.They performed Univariate and multivariate Cox regression analyses to evaluate whether salvage RT in men with either a rapid (< 6 months) or a protracted (? 6 months) PSA DT was associated with the risk of all-cause mortality. They adjusted their statistics for age at the time of PSA failure, known prostate cancer prognostic factors, and cardiac co-morbidity.They found that after a median follow-up of 11.3 years after PSA failure, 195 men died.They found that salvage RT was associated with a significant reduction in all-cause mortality for men with either a PSA DT of < 6 months (adjusted hazard ratio [AHR], 0.53; P = .02) or a PSA DT of ? 6 months (AHR, 0.52; P = .003). They found that in a subset of men with comorbidity data at the time of PSA failure, salvage RT remained associated with a significant reduction in all-cause mortality for both men with a PSA DT of < 6 months (AHR, 0.35; P = .042) or a PSA DT of ? 6 months (AHR, 0.60; P = .04).They found that salvage RT for PSA DTs less than or in excess of 6 months is also associated with a decreased risk in all-cause mortality.Bottom Line – Salvage radiation after a PSA recurrence post-surgery contributes to lower morbity, or to longer life, no matter what is the PSA doubling rate.
Cotter, SE; Chen, MH; Moul, JW; Lee, WR; Koontz, BF; Anscher, MS; Robertson, CN; Walther, PJ; Polascik, TJ; D’Amico, AV. Salvage radiation in men after prostate-specific antigen failure and the risk of death. Cancer. 2011;117:3925-3932. (2011)
Joel T. Nowak, M.A., M.S.W.