Preoperative Favorable Characteristics in Bladder Cancer Patients Cannot Substitute the Necessity of Extended Lymphadenectomy During Radical Cystectomy: A Sensitivity Curve Analysis.

OBJECTIVE: To investigate the staging of lymphadenectomy during radical cystectomy (RC) due to bladder cancer. No data exist about the possibility to limit the extension of pelvic lymph node dissection (PLND) on the basis of preoperative or intraoperative parameters without losing accuracy in the staging procedure. MATERIALS AND METHODS: Between 1995 and 2012, 1016 RC due to bladder cancer were performed at a single tertiary care institution. The relationship between the number of nodes removed and the probability to find node metastases at final pathology examination was assessed using receiver operating characteristic analyses. RESULTS: Among the patients who underwent RC plus PLND, the lymph node metastases prevalence was 35.7% (363 of 1016). Receiver operating characteristic curve analyses were used to explore graphically the relationship between the numbers of removed and examined nodes and the probability of finding one or more metastatic nodes in the overall population. The curve indicated that 25, 35, and 45 nodes need to be removed to achieve 75%, 90%, and 95% probability, respectively, of detecting one or more lymph node metastases. When the analyses were stratified according to preoperative characteristics, only slight differences were recorded among the sensitivity analyses stratified for pathological stage, primary or progressive status, or radiological N status. CONCLUSION: Our results show that it is necessary to extend PLND to improve the ability to stage node metastases accurately. Preoperative parameters can minimally change this indication and an extended PLND should be always performed.