Stage-specific impact of extended versus standard pelvic lymph node dissection in radical cystectomy

Objectives To evaluate the impact of an extended versus a standard pelvic lymph node dissection on disease-free survival and cancer-specific survival of patients with non-metastatic muscle-invasive urothelial carcinoma of the bladder treated with radical cystectomy. Methods We retrospectively analyzed data of 933 patients collected in two prospectively-maintained institutional databases between 2002 and 2010. Patients who met inclusion criteria (high-grade urothelial carcinoma, have not undergone neoadjuvant treatments, have not undergone salvage cystectomy) were included for analysis. The upper boundary was the iliac bifurcation for standard lymph-node dissection and the aortic bifurcation for the extended lymph node dissection, respectively. Univariable and multivariable Cox regression analyses were carried out to identify independent predictors of disease-free survival and cancer-specific survival and, subsequently, the effect of extended lymph node dissection was determined with a multivariable Cox analysis after stratifying for significant covariates. Results At multivariable analysis, once adjusted for the effect of the other covariates, extended lymph node dissection was an independent predictor of disease-free survival (hazard ratio 1.95, P<0.001) and cancer-specific survival (hazard ratio 1.80, P<0.001). The benefit of an extended pelvic lymph node dissection on disease-free survival and cancer-specific survival was significant across all pT stages (all P<0.05) except for pT <2 and across all pN stages (pN=0, P=0.011 and P=0.034 for disease-free survival and cancer-specific survival, respectively; pN1 and pN2, all P<0.001). Conclusions The staging accuracy and the survival benefit provided by extended pelvic lymph node dissection suggests the adoption of this template as the standard template for patients with muscle-invasive urothelial carcinoma of the bladder undergoing radical cystectomy.