The SWOG trial of 431 men with pT3N0M0 prostate cancer, randomized to 60-64 Gy adjuvant radiotherapy or observation. 70 of the observation group recieved salvage RT at failure. DM free survival improved with RT (HR 0.71; 95% CI 0.54, 0.94; p = 0.016), and OS improved with RT (HR 0.72; 95% CI 0.55, 0.96; p = 0.023).
This is an extremely important trial, in while adjuvant RT has been demonstrated to improve BRFS in two additional trials (EORTC and a German Trial), this is the first to demonstrate that this translates into a survival benefit. This is especially relavent when only ~ 15% of patients with pT3 disease are actually referred for RT (unpublished data) nationally. Duke has done a little better recently with ~35% of patients being referred.