This study compared the effect of aRT vs. eSRT on biochemical recurrence (BCR) free survival in a large multi-institutional cohort of men undergoing radical prostatectomy (RP), pelvic lymph node dissection and subsequent aRT or eSRT. The cohort consisted of 515 patients treated with RP and either aRT or eSRT at three tertiary care centers; 420 pT2-4 R0-R1 pN0 patients (81.5%) who received either immediate aRT with undetectable PSA after surgery (n=313, 74.5%) or eSRT (defined as RT administered with a PSA value <0.5 ng/ml; n=107, 25.5%) were identified. The effect of aRT vs. eSRT on BCR-free survival rates was determined by retrospective matched case-control analysis for pathologic stage, pathologic Gleason score and surgical margin (SM) status. The same analyses were repeated using a PSA cut-off <0.3 ng/ml to define eSRT (n= 79) as well as in those patients who received higher RT doses (≥66 Gy).
Mean follow-up was 78.5 months. In the overall patient population the 2, 5, and 8-years BCR free survival rates were 95.4%, 84.7% and 78.1%, 88%, 65.4% and 44.6% in patients treated with aRT and eSRT, respectively (p<0.001). Among 420 RP patients, 143 of 313 (45.7%) patients treated with aRT were matched with 89 of 107 (83.2%) patients who received eSRT with a PSA value <0.5 ng/ml. After matching, no differences were found regarding clinical or pathological characteristics. The 2, 5, and 8-year BCR free survival rates were 95%, 82.3% and 72.8% in aRT vs. 85.4%, 65.5% and 45.9% in eSRT patients (aRT vs. eSRT, HR 0.6; p=0.038). Similar results were obtained when post-RP PSA cut-off to define eSRT was set at 0.3 ng/ml (2, 5, and 8-year BCR free survival rates were 91.7%, 78.4% and 70.7% vs. 81.5%, 63.9% and 44.2% in aRT and eSRT patients, respectively, HR 0.37; p<0.001). Adjuvant RT was also associated with higher BCR free survival rates when the analysis was restricted to those patients receiving higher RT dose (≥66 Gy; p≤0.027). These data suggest that aRT may be superior, but a prospective trial would provide better clarification and use of ultrasensitive PSA testing may provide earlier initiation of eSRT.
Presented by Alberto Briganti, MD, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria