Neoadjuvant and adjuvant chemotherapy in muscle-invasive bladder cancer: Real-world analysis of chemotherapy use and impact on patient outcomes.

Abstract

Background: The optimal management of muscle-invasive bladder cancer (MIBC) consists of neoadjuvant platinum-based chemotherapy followed by radical cystectomy. While adjuvant chemotherapy is used, there is a lack of high-level evidence to support this approach. We analysed the effect of neoadjuvant and adjuvant chemotherapy for MIBC in an Australian real-world population, described patterns of chemotherapy use and explored differences between treatment groups. Method(s): The BLADDA registry, a multicentre Australian registry of muscle-invasive and advanced urothelial cancer, was searched to identify patients with MIBC treated with curative-intent surgery. Clinical, pathological and survival data were analysed. Differences between patients treated with and without chemotherapy were tested using univariate and multivariable logistic regression. Multivariable proportional hazards models were used to compare recurrence-free survival (RFS) and overall survival (OS) in patients treated with neoadjuvant chemotherapy, adjuvant chemotherapy or surgery alone. Result(s): 158 patients underwent surgery for MIBC between 2006 and 2022. 36.7% were given neoadjuvant chemotherapy, 20.3% received adjuvant chemotherapy and 43.0% had surgery only. The proportion of patients given neoadjuvant chemotherapy rose from 8.1% in 2006-2015 to 60.5% in 2020-2022. Compared to surgery alone, RFS was improved in patients treated with neoadjuvant chemotherapy (HR 0.38, 95% CI 0.18-0.82, p=0.014) or adjuvant chemotherapy (HR 0.37, 95% CI 0.18-0.75, p=0.006). OS was longer in the neoadjuvant chemotherapy group (HR 0.38, 95% CI 0.16-0.93, p=0.034) but not in the adjuvant chemotherapy group (HR 0.48, 95% CI 0.20-1.13, p=0.092). Patients were less likely to receive chemotherapy if they were older (OR 0.92 [age as a continuous variable], 95% CI 0.87-0.97, p=0.003) or had renal impairment (OR 0.29, 95% CI 0.10-0.86, p=0.025). Conclusion(s): In a real-world analysis of Australian patients with MIBC, neoadjuvant chemotherapy was associated with improved RFS and OS, but adjuvant chemotherapy was associated with improved RFS only. Older patients and those with renal impairment were less likely to be treated with chemotherapy. Legal entity responsible for the study: The authors. Funding(s): Walter and Eliza Hall Institute for Medical Research. Disclosure: All authors have declared no conflicts of interest.Copyright © 2022