Effect of Complete Transurethral Resection on Oncologic Outcomes After Radiation Therapy for Muscle-Invasive Bladder Cancer

PURPOSE: To compare the oncologic outcomes of patients with nonmetastatic muscle-invasive bladder cancer (MIBC) undergoing complete versus incomplete transurethral tumor resection (TURBT) before radiation therapy. METHODS AND MATERIALS: Patients with nonmetastatic MIBC who underwent curative-intent radiation therapy between 2002 and 2018 at 10 Canadian institutions were retrospectively evaluated. Inverse probability of treatment weighting was performed using baseline characteristics. Differences in survival outcomes by complete and incomplete TURBT were analyzed. RESULTS: Of the 757 patients included, 66% (498) had documentation of a complete and 34% (259) an incomplete TURBT. Before adjustment, 121 (47%) and 45 (9%) patients who underwent incomplete and complete TURBT, respectively, were diagnosed with cT3-4 tumor (P <.001). After weight-adjustment, all baseline cohort characteristics were balanced (absolute standardized differences < 0.1). The adjusted median follow-up was 27 months. Adjusted survival analyses showed no significant difference in 5-year overall survival (48% vs 52%, 1.03 [0.82-1.29]; P = .8), cancer-specific survival (64% vs 61%, 0.93 [0.70-1.25]; P = .7), metastasis-free survival (43% vs 46%, 0.97 [0.79-1.19]; P = .8), and disease-free survival (32% vs 35%, 0.95 [0.79-1.15]; P = .7) between the 2 groups. CONCLUSIONS: Complete TURBT may be associated with clinical organ-confined disease. Extent of TURBT was not independently associated with oncologic outcomes in patients with MIBC treated with radiation therapy.