On Sunday at the AUA conference there was a poster (#159) titled ADJUVANT VS. SALVAGE RADIATION THERAPY FOLLOWING PROSTATECTOMY FOR LOCALLY ADVANCED PROSTATE CANCER: RESULTS FROM SEER-MEDICARE written by Keith J. Kowalczyk, etal. The researchers evaluated the optimal timing of external beam radiation (RT) after the completion of a radical prostatectomy (RP) as primary treatment for prostate cancer. The big debate centers on when to use RT. Some clinicians favor its use as adjuvant therapy (therapy prior to any sign of a recurrence) while others reserve RT only at the time of a recurrence (salvage therapy).
The researchers performed a population-based analysis to determine whether there is a survival benefit for post-RP adjuvant versus salvage RT. They used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data from 1995-2005, and identified 1692 men undergoing RP who received adjuvant (n=772) versus salvage RT (n=920).
The research outcomes included overall survival (OS), disease specific survival (DSS), bone-related events (pathologic fracture and/or metastasis), and use of salvage hormone therapy (administered more than 12 months following RT).
They found that:
1- Men undergoing adjuvant versus salvage RT were more likely to have poorly differentiated tumors (60.9% vs. 48.6%, p<0.001), however they experienced improved disease specific survival (DSS) by 98.7% vs. 95.4%, improved overall survival (OS) by 85.4% vs. 80.7%, and fewer bone-related events 14.1% vs. 21.3%.2- Using time-at-risk analyses, the men who underwent adjuvant vs. salvage RT experienced improved disease specific survival (DS), 0.29 vs. 1.0 prostate cancer related deaths/100 person years and fewer bone related events, 2.60 vs. 3.07 events/100 person years.3- However, adjuvant versus salvage RT was also associated with greater use of salvage hormonal therapy (1.74 vs. 1.08 events/100 person years) and similar overall survival (OS), 2.46 vs. 3.07 events/100 person years. The conclusions are clear:There conclusions from this study were:1- Men undergoing adjuvant vs. salvage RT had improved disease specific survival (DSS) as well as fewer bone related events.2- Overall survival is similar in those undergoing adjuvant versus salvage RT, although there was a trend favoring adjuvant RT.Since this is a population prospective analysis it does not qualify as level one evidence, however it does provide an insight which should be considered when trying to decide on the use of adjuvant vs. salvage therapy after failed prostate cancer surgery.Joel T. Nowak, M.A., M.S.W.