Neoadjuvant chemotherapy for muscle invasive bladder cancer: a nationwide investigation on survival.

Randomised controlled trials (RCTs) have investigated the use of neoadjuvant chemotherapy (NAC) and its effect on survival patients with non-metastatic muscle-invasive bladder cancer (MIBC). However, these RCTs have limited external validity and generalisability and, therefore, the current study aims to use real world evidence in the form of observational data to identify the effect that NAC may have on survival, compared to the use of radical cystectomy (RC) alone. The study cohort (consisting of 944 patients) was selected as a target trial from the Bladder Cancer Data Base Sweden (BladderBaSe). This study calculated 5-year survival and risk of bladder cancer (BC)-specific and overall death by Cox proportional hazard models for the study cohort and a propensity score (PS) matched cohort. Those who had received NAC had higher 5-year survival proportions and decreased risk of both overall and BC specific death (HR = 0.71, 95% CI = 0.52-0.97 and HR = 0.67, 95% CI = 0.48-0.94), respectively, as compared to patients who did not receive NAC. The PS matched cohort showed similar estimates, but with larger statistical uncertainty (Overall death: HR = 0.76, 95% CI = 0.53-1.09 and BC-specific death: HR = 0.73, 95% CI = 0.50-1.07). Results from the current observational study found similar point estimates for 5-year survival and of relative risks as previous studies. However, the results based on real world evidence had larger statistical variability, resulting in a non-statistically significant effect of NAC on survival. Future studies with detailed validated data can be used to further investigate the effect of NAC in narrower patient groups.