Association Between the Number of Dissected Lymph Nodes During Pelvic Lymphadenectomy and Cancer-Specific Survival in Patients with Lymph Node–Negative Urothelial Carcinoma of the Bladder Undergoing Radical Cystectomy

Background A larger number of dissected lymph nodes (LN) during pelvic lymphadenectomy in patients with muscle-invasive transitional-cell carcinoma of the bladder treated by radical cystectomy (RC) is crucial for exact tumor staging and is associated with a positive oncological outcome. Methods Clinical and pathological records of 1291 patients undergoing RC due to LN-negative transitional-cell carcinoma of the bladder were summarized and evaluated in a multi-institutional database. The number of removed LNs and the presence or absence of lymphovascular invasion were assessed. On the basis of multivariate Cox regression analyses, a threshold number of removed LNs was defined that exerted an independent influence on cancer-specific survival (CSS). Results In multivariate Cox regression models for different numbers of removed LNs, a statistically significant enhancement of CSS could be demonstrated for a LN count of 16. Furthermore, the integration of the dichotomized LN count of 16 resulted in a statistically significantly enhanced predictive ability of the model for CSS. Patients with