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 lymphnode dissection on disease-free survival and cancer-specific survival of patients withnon-metastatic muscle-invasive urothelial carcinoma of the bladder treated with radicalcystectomy.Methods: We retrospectively analyzed data of 933 patients collected in twoprospectively-maintained institutional databases between 2002 and 2010. Patients whomet inclusion criteria (high-grade urothelial carcinoma, have not undergone neoadjuvanttreatments, have not undergone salvage cystectomy) were included for analysis.The upper boundary was the iliac bifurcation for standard lymph-node dissection andthe aortic bifurcation for the extended lymph node dissection, respectively. Univariableand multivariable Cox regression analyses were carried out to identify independentpredictors of disease-free survival and cancer-specific survival and, subsequently, theeffect of extended lymph node dissection was determined with a multivariable Coxanalysis 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 andcancer-specific survival was significant across all pT stages (all P < 0.05) except for pT <2and across all pN stages (pN = 0, P = 0.011 and P = 0.034 for disease-free survival andcancer-specific survival, respectively; pN1 and pN2, all P < 0.001).Conclusions: The staging accuracy and the survival benefit provided by extendedpelvic lymph node dissection suggests the adoption of this template as the standardtemplate for patients with muscle-invasive urothelial carcinoma of the bladder undergoingradical cystectomy.Key words: bladder cancer, lymph node dissection, radical cystectomy, urothelialcarcinoma.IntroductionDespite the evidence of a staging role of PLND during RC, its therapeutic role is stillunknown and a standard template of PLND has yet to be defined.1According to the 2009 TNM staging system, an appropriate pathological nodal stagingduring RC should include all pelvic nodes together with presacral and common iliac nodes,as the pN3 category would be not applicable to patients not undergoing an e-PLND.2In 2009, Hellenthal et al. observed that PLND was omitted in 21% of patients undergoingRC and more frequently in early-stage diseases.3More recently, in a retrospective analysis of data from the SEER database, Abdollah et al.showed the increased risk of cancer-specific mortality in patients not receiving PLNDduring RC, especially in patients with early-stage disease.4In 2004, Abol-Enein et al. highlighted the minimal risk of nodal metastasis outside thetrue pelvis in patients without metastasis in pelvic nodes.