Salvage radiation in men after prostate-specific antigen failure and the risk of death.

BACKGROUND: A survival benefit has been observed with salvage radiation therapy (RT) for prostate-specific antigen (PSA) failure after radical prostatectomy (RP) in men with rapid rises in PSA doubling time (DT, < 6 months). Whether such a benefit exits in men with a protracted PSA rise in DT (≥ 6 months) is unclear and was examined in the current study.
METHODS: Of 4036 men who underwent RP at Duke University between 1988 and 2008, 519 experienced a PSA failure, had complete data, and were the subjects of this study. Univariate and multivariate Cox regression analyses were performed 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 adjusting for age at the time of PSA failure, known prostate cancer prognostic factors, and cardiac comorbidity.
RESULTS: After a median follow-up of 11.3 years after PSA failure, 195 men died. 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). In a subset of patients 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).
CONCLUSIONS: Salvage RT for PSA DTs less than or in excess of 6 months is associated with a decreased risk in all-cause mortality. Cancer 2011