Extended lymphadenectomy and adjuvant chemotherapy in muscle-invasive bladder cancer treated by radical cystectomy.

Abstract

287 Background: Level 1 evidence is weak for adjuvant chemotherapy (AC) after cystectomy, but surveys indicate physicians refer patients for AC more frequently than for neoadjuvant chemotherapy (NC). The exact benefit of an extended pelvic lymph node dissection (ePLND) remains debated. We addressed the issue of AC and ePLND analyzing two academic centers RC databases with opposite approaches, one using ePLND and AC, the other performing a limited lymph node dissection and no AC. Methods: Two ethics approved RC databases including consecutive BC patients undergoing RC at the University Health Network, Canada and the University of Turku, Finland were studied. Excluding non-urothelial cases and patients receiving NC, 563 patients were available for analysis. Clinicopathological variables, rate and extent of PLND and rate of adjuvant cisplatin-based chemotherapy were analyzed using the χ2-test. Kaplan-Meier method and multivariate Cox regression analysis were used to analyze survival. Results: In Toronto, patients had more extensive PLNDs (>10 nodes removed, 58% vs. 8%, p<0.001), higher rate of nodal metastases (26% vs. 7%, p<0.001), and received more often AC (21% vs. 1%, p<0.001). Positive margin rates were similar (4% in both centers). No BC specific survival difference was demonstrated in ≤ pT2a or in pT4a tumors. There was a trend for improved survival in pT2b tumors (10y BC specific survival 65% vs. 42%, p=0.23) and a significant difference favouring the Toronto cohort in pT3a and pT3b tumors (55% vs. 31%, p=0.025; 43% vs. 28% p=0.06, respectively). In multivariate analysis, N-stage (HR 2.5, 95% CI 1.5-4.1; p<0001) and ePLND (HR 0.53, 95% CI 0.31-0.93, p=0.026) significantly affected disease specific survival. The benefit of AC did not reach significance (HR 0.61, 95% CI 0.36-1.05, p=0.072). An interaction model combining ePLND and AC was significantly related to improved outcome (HR 0.49, 95% CI 0.26-0.92, p=0.026). Conclusions: Despite not being randomized, using 2 study cohorts that received completely opposite managements in terms of ePLND and AC, our results support that ePLND and AC may offer a survival advantage in T2b and especially in T3 BC treated with RC.