Effectiveness of Adjuvant Chemotherapy for Locally Advanced Bladder Cancer

Abstract

Purpose: Given that randomized trials exploring adjuvant chemotherapy for bladder cancer have been underpowered and/or terminated prematurely, yielding inconsistent results and creating an evidence gap, we sought to compare the effectiveness of cystectomy versus cystectomy plus adjuvant chemotherapy in real-world patients.

Patients and methods: We conducted an observational study to compare the effectiveness of adjuvant chemotherapy versus observation postcystectomy in patients with pathologic T3-4 and/or pathologic node-positive bladder cancer using the National Cancer Data Base. We compared overall survival using propensity score (-adjusted, -stratified, -weighted, and -matched) analyses based on patient-, facility-, and tumor-level characteristics. A sensitivity analysis was performed to examine the impact of performance status.

Results: A total of 5,653 patients met study inclusion criteria; 23% received adjuvant chemotherapy postcystectomy. Chemotherapy-treated patients were younger and more likely to have private insurance, live in areas with a higher median income and higher percentage of high school-educated residents, and have lymph node involvement and positive surgical margins (P < .05 for all comparisons). Stratified analyses adjusted for propensity score demonstrated an improvement in overall survival with adjuvant chemotherapy (hazard ratio, 0.70; 95% CI, 0.64 to 0.76), and similar results were achieved with propensity score matching and weighting. The association between adjuvant chemotherapy and improved survival was consistent in subset analyses and was robust to the effects of poor performance status.

Conclusion: In this observational study, adjuvant chemotherapy was associated with improved survival in patients with locally advanced bladder cancer. Although neoadjuvant chemotherapy remains the preferred approach based on level I evidence, these data lend further support for the use of adjuvant chemotherapy in patients with locally advanced bladder cancer postcystectomy who did not receive chemotherapy preoperatively.