Prognostic Impact of Post-Diagnosis Smoking Cessation among Bladder Cancer Patients: A Systematic Literature Review and Meta-Analysis

Simple Summary Cigarette smoking increases the risk of developing bladder cancer; many of these patients are active smokers at diagnosis. There is evidence that smokers with cancer at other sites (e.g., lung) may improve their chance of surviving if they stop smoking upon diagnosis. However, similar evidence is still lacking for bladder cancer. Here, we reviewed the scientific literature up to January 2022 but found a mere nine articles focusing on this topic, which provided insufficient evidence to draw firm conclusions. While more research is urgently needed, bladder cancer patients who are still smoking at diagnosis should receive information on the multiple health benefits of smoking cessation and all the support they need to stop successfully. Abstract: We reviewed the studies examining whether quitting smoking at or around diagnosis favourably affects the prognosis of bladder cancer (BC) patients, who are often active smokers at diagnosis. We found only nine eligible articles published until 31 January 2022, which encompassed around 5500 BC in total, the majority of which were nonmuscle invasive BC (only one paper included muscle-invasive BC). We used random effects meta-analysis to obtain a summary hazard ratio (SHR) and 95% confidence intervals (CI). The median proportion of smokers who quit at or around diagnosis was 29.8% (range 8.4-43.1%). For the overall, BC-specific, and progression-free survival, the studies were limited in number (n = 3) and provided conflicting results. At the same time, quitters did not appear to have a lower risk of recurrence than continued smokers (SHR 0.99, 95% CI 0.61-1.61). In conclusion, while the evidence is currently not sufficient to draw firm conclusions (especially for patients with muscle-invasive BC), physicians should not refrain from educating smoking BC patients about the benefits of smoking cessation and provide the necessary support.