Importance: Tobacco smoking is an established risk factor associated with bladder cancer, yet its impact on bladder cancer prognosis is unclear.
Objective: To examine associations of use of tobacco (cigarettes, pipes, and cigars), e-cigarettes, and marijuana with risk of recurrence and progression of non-muscle-invasive bladder cancer (NMIBC) and to explore use of smoking cessation interventions.
Design, setting, and participants: The Be-Well Study is a prospective cohort study of patients with NMIBC diagnosed from 2015 to 2019 and followed-up for 26.4 months in the Kaiser Permanente Northern and Southern California integrated health care system. Eligibility criteria were age at least 21 years, first NMIBC diagnosis (stages Ta, Tis, or T1), alive, and not in hospice care. Exclusion criteria were previous diagnosis of bladder cancer or other cancer diagnoses within 1 year prior to or concurrent with NMIBC diagnosis. Data were analyzed from April 1 to October 4, 2022.
Exposures: Use of cigarettes, pipes, cigars, e-cigarettes, and marijuana was reported in the baseline interview. Use of smoking cessation interventions (counseling and medications) was derived from electronic health records.
Main outcomes and measures: Hazard ratios (HRs) and 95% CIs of recurrence and progression of bladder cancer were estimated by multivariable Cox proportional hazards regression.
Results: A total of 1472 patients (mean [SD] age at diagnosis, 70.2 [10.8%] years; 1129 [76.7%] male patients) with NMIBC were enrolled at a mean (SD) of 2.3 (1.3) months after diagnosis, including 874 patients (59.4%) who were former smokers and 111 patients (7.5%) who were current cigarette smokers; 67 patients (13.7%) smoked pipes and/or cigars only, 65 patients (4.4%) used e-cigarettes, 363 patients (24.7%) used marijuana. Longer cigarette smoking duration and more pack-years were associated with higher risk of recurrence in a dose-dependent manner, with the highest risks for patients who had smoked for 40 or more years (HR, 2.36; 95% CI, 1.43-3.91) or 40 or more pack-years (HR, 1.97; 95% CI, 1.32-2.95). There was no association of having ever smoked, being a former or current cigarette smoker, and years since quit smoking with recurrence risk. No associations with pipes, cigars, e-cigarettes, or marijuana were found. Of 102 patients offered a smoking cessation intervention, 57 (53.8%) received an interventions after diagnosis, with female patients more likely than male patients to engage in such interventions (23 of 30 female patients [76.7%] vs 34 of 76 male patients [44.7%]; P = .003).
Conclusions and relevance: These findings suggest that longer duration and more pack-years of cigarette smoking were associated with higher risk of NMIBC recurrence. Cigarette smoking remains a critical exposure before and after diagnosis in survivors of NMIBC.