The association between smoking cessation before and after diagnosis and non-muscle-invasive bladder cancer recurrence::a prospective cohort study

Background: Smoking is a major risk factor for bladder cancer, but the relationship between smoking cessation after initial treatment and bladder cancer recurrence has been investigated less frequently and not prospectively yet.Methods: 722 non-muscle-invasive bladder cancer (NMIBC) patients (pTa, pT1 and CIS) from the prospective Bladder Cancer Prognosis Programme (BCPP) cohort, selected in the UK between 2005-2011, provided complete data on smoking behaviour before and up to 5 years after diagnosis. The impact of smoking behaviour on NMIBC recurrence was explored by multivariable Cox regression models investigating time-to-first NMIBC recurrence.Results: Over a median follow-up period of 4.21 years, 403 pathologically confirmed NMIBC recurrences occurred in 210 patients. Only 25 current smokers at diagnosis quit smoking (14%) during follow-up and smoking cessation after diagnosis did not decrease risk of recurrence compared to continuing smokers (p=0.352). Conclusions: Although quitting smoking after diagnosis might reduce the risk of recurrence based on retrospective evidence, this is not confirmed in this prospective study because the number of NMIBC patients quitting smoking before their first recurrence was too low. Nevertheless, this indicates an important role for urologists and other health care professionals in promoting smoking cessation in NMIBC.