Real-World Efficacy of Postoperative Intravesical Chemotherapy After Transurethral Resection of Bladder Tumor in Older Adults

Purpose: Randomized trials report improved recurrence rates with a single postoperative instillation of intravesical chemotherapy (POC) after transurethral resection of bladder tumor (TURBT). However, real-world data on the effectiveness of POC are lacking and clinical adoption remains low. Here, we evaluated the contemporary utilization and effectiveness of POC after TURBT.Materials and Methods: Observational analyses emulated the SWOG 0337 trial among patients aged 66–74 with cTaN0M0 bladder cancer from 2000–2017 in the Linked Surveillance Epidemiology and End Results-Medicare dataset. After estimating propensity scores, we evaluated efficacy of POC after TURBT using inverse probability of treatment weights. The primary outcome was recurrence-free survival (RFS), with secondary outcomes of progression-free survival (PFS) and perioperative adverse events.Results: Of 10,991 patients, 9,424 (86%) were treated with TURBT alone and 1,567 (14%) with additional POC. TURBT + POC was associated with improved RFS, but not PFS, compared to TURBT alone, with 5-year RFS of 50% vs 40% (HR 0.80, 95% CI 0.71–0.90, p < 0.01), respectively. Results were similar across tumor size and grade, and age. In multivariable analyses, later diagnosis (OR 19.6, 95% CI 14.5–26.4), higher income (OR 1.37, 95% CI 1.07–1.77), and higher education level (OR 1.38, 95% CI 1.05–1.81) were associated with increased odds of receiving POC, while lower odds were observed in older age (OR 0.97, 95% CI 0.95–0.99).Conclusions: POC after TURBT was associated with improved RFS, irrespective of tumor grade or size, but not improved PFS. However, POC remains underutilized especially among older, lower education, and lower income patients.