The Role of Lymph Node Dissection in Patients With Muscle-Invasive Bladder Cancer Who Underwent Radical Cystectomy Following Neoadjuvant Chemotherapy.

Background: The interaction between lymph node dissection (LND) during radical cystectomy (RC) and neoadjuvant chemotherapy (NAC) remains unclear. This study aimed to evaluate the role of LND in patients undergoing RC after NAC.

Patients And Methods: We retrospectively analyzed 259 patients with muscle-invasive bladder cancer (MIBC) who underwent RC following NAC at Fujita Health University Hospital and Fujita Health University Okazaki Medical Center between 2010 and 2022. Baseline characteristics, pathological outcomes, recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were compared between propensity score (PS)-matched cohorts.

Results: PS matching analysis resulted in 94 matched pairs from the adequate (standard or extended template) and inadequate (limited template or unilateral- or no-LND) LND groups. The median number of dissected nodes was significantly higher in the adequate LND group than in the inadequate LND group (19 vs. 5, P < .001). Similarly, a higher pathological node-positive rate (ypN+) was observed in the adequate group than in the inadequate group (18.1% vs. 7.4%, P = .03). The adequate LND group identified more ypN+ with ≤ ypT1 cases than the inadequate group (4 vs. 1). There were no statistically significant differences between the adequate and inadequate groups in RFS (P = .94), CSS (P = .54), and OS (P = .65). Subgroup analysis also showed comparable survival rates, even in patients with ≥ pT3 or cN+ disease. ypN+ was an independent predictor of OS in the Cox regression analysis, while adequate LND and the number of lymph nodes removed (≥10 or ≥15) were not associated with survival.

Conclusions: Although adequate LND did not show a significant therapeutic effect in RC after NAC, adequate LND may have an important diagnostic role in detecting ypN+, which is a robust predictor, and is a useful biomarker to perform appropriate adjuvant immunotherapy especially in ≤ ypT1 cases.