The association between extent of lymphadenectomy and survival among patients with lymph node Metastases undergoing radical cystectomy

BACKGROUND. Long-term survival in patients with lymph node-positive bladder cancer who undergo cystectomy suggests a therapeutic role for lymphadenectomy. The objective of this study was to describe the association between extent of lymphadenectomy and survival in lymph node-positive patients who underwent radical cystectomy. METHODS. The cohort consisted of patients from the Surveillance, Epidemiology, and End Results registry with transitional cell carcinoma who underwent cystectomy with lymphadenectomy and had at least I positive lymph node and no distant metastases. The Kaplan-Meier method and multivariate Cox proportional-hazards regression analyses were used to estimate differences in survival among different lymphadenectomy variables. RESULTS. In total, 1260 patients had at least I positive lymph node. A median of 9 lymph nodes were removed (range, 1-48 lymph nodes) with a median of 2 positive lymph nodes (range, 1-18 positive lymph nodes), and the median lymph node density was 22%. In multivariate analysis controlling for patient demographics, tumor classification, and year of diagnosis, the number of positive and total lymph nodes removed remained independent predictors of survival. There was an inverse association between the number of lymph nodes removed and the risk of death for all quartiles. Removal of > 10 lymph nodes was associated with increased overall survival (hazard ratio, 0.52; 95% confidence interval, 0.43-0.64). In addition, with a lymph node density from 0.1% to 12.5% as the referent group, each higher quartile experienced worse survival. CONCLUSIONS. An increased number of lymph nodes removed at the time of cystectomy was associated with improved survival in patients with lymph node-positive bladder cancer. Improved survival was observed at a lower lymph node density threshold than previously reported. The current findings support performing a more extensive lymphadenectomy at the time of cystectomy.