Lymph node count at radical cystectomy does not influence long-term survival if surgeons adhere to a standardized template

Abstract

INTRODUCTION: Multiple bladder cancer studies report that the number of removed lymph nodes (lymph node count [LNC]) at radical cystectomy (RC) is positively associated with survival. Although these reports suggest that LNC can be used as a proxy for surgical quality, all studies used variable or inconsistent pelvic lymph node dissection (PLND) templates. We therefore wished to establish whether LNC at RC influences survival if surgeons adhere to a standardized PLND template. MATERIALS AND METHODS: We included 274 patients who underwent RC from January 2005 until December 2012. All RCs were performed in either one of 2 hospitals (hospital A or B) by the same 4 urologists (all from hospital A) and a standardized PLND template was applied. PLND specimens were processed by 2 independent pathology departments (hospital A and B). We used Cox regression analysis to investigate the prognostic value of LNC adjusted for patient characteristics. We also compared LNC between hospitals and surgeons and investigated the effect of both the variables on overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). RESULTS: Median LNC was 17 (interquartile range = 12). At a median follow-up of 64.3 months, there was no association between LNC and OS (P = 0.328), CSS (P = 0.645), or DFS (P = 0.450). Median LNC was higher in hospital B than in hospital A (20.0 vs. 16.0, P = 0.003). Median LNC varied significantly among surgeons (12-20, P<0.001). Neither the hospital of surgery nor the surgeon performing PLND influenced OS (P = 0.771 and P = 0.982, respectively), CSS (P = 0.310 and P = 0.691, respectively), or DFS (P = 0.256 and P = 0.296, respectively). CONCLUSION: If surgeons adhere to a standardized template, LNC at RC does not affect long-term survival.