Smoking status and pathological response to neoadjuvant chemotherapy among patients with bladder cancer: a pooled analysis

Background Smoking status has been confirmed as an independent prognostic factor for bladder cancer. However, for patients who received neoadjuvant chemotherapy (NAC), the influence of smoking status on the pathological response and prognosis remains unclear. This pooled analysis aimed to investigate whether smoking status is an independent risk factor for pathological response, recurrence, and prognosis in patients with bladder cancer who undergo NAC. Methods We searched PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar for related studies published between 1990 and 2017. In total, 10 studies comprising 1,382 patients with muscle-invasive bladder cancer were included. The odds ratio (OR) and 95% confidence interval (CI) of complete pathological response, partial pathological response, overall survive (OS), recurrence, and cancer-specific mortality (CSM) were chosen as outcome measures. Analyses were performed using Review Manager (version 5.3, The Cochrane Collaboration, UK) and Stata statistical software (version 15, Stata Corp., USA). Results Compared to nonsmokers, smokers were less likely to have a complete pathologic response (OR =0.55, 95% CI: 0.35-0.87) and partial pathological response (OR =0.57, 95% CI: 0.37-0.88). However, we found no significant association between smoking status and overall survival (OR =0.71, 95% CI: 0.28-1.80), recurrence (OR =1.35, 95% CI: 0.97-1.88), and cancer-specific mortality (OR =0.90, 95% CI: 0.62-1.32). Conclusions Smoking reduces both complete and partial pathological response rate to NAC in patients with bladder cancer. Thus, smoking status should be given more importance when developing treatment plans and evaluating efficacy, particularly of NAC, among bladder cancer patients.