Outcomes of Patients with Bacillus Calmette-Guérin (BCG)-Unresponsive Non-Muscle Invasive Bladder Cancer as Defined by the U.S. Food and Drug Administration

BACKGROUND: Limited data are available on the outcomes of patients with non-muscle invasive bladder cancer (NMIBC) unresponsive to intravesical bacillus Calmette-Guérin (BCG), as defined by the United States Food and Drug Administration. OBJECTIVE: To define the outcomes of patients with BCG-unresponsive NMIBC. METHODS: This was a retrospective, single-institution observational cohort study. Records of patients managed at our institution for BCG-unresponsive NMIBC between 2005 and 2020 were reviewed and clinical outcomes evaluated. RESULTS: The study included 149 patients. Management was with initial radical cystectomy in 60 patients (40%) and initial bladder-sparing therapy (BST) in 89 patients (60%). Overall survival was greater among patients undergoing RC than BST (HR 1.83, 95% CI 1.04-3.22, p = 0.036), potentially due to patient selection, as no significant difference was noted for metastasis-free or cancer-specific survival. Patients opting for initial BST had high rates of treatment failure, with estimated 5-year cystectomy-free survival of only 42%. Patients who received additional lines of BST after a subsequent failure were at increased risk of having ≥pT3 or pN+ disease at cystectomy (42% for ≥2 lines BST, versus 18% for 1 line BST and 15% for initial cystectomy, p = 0.038). CONCLUSION: Among patients who underwent initial BST for BCG-unresponsive NMIBC, rates of treatment failure were very high. Patients who underwent delayed cystectomy after ≥2 lines of BST had elevated rates of extravesical disease. Our observations emphasize the importance of recent and ongoing clinical trials in this clinical space.