Smoking duration, intensity tied to bladder cancer recurrence

Longer duration and more pack-years of cigarette smoking are associated with a higher risk for recurrence of non-muscle-invasive bladder cancer (NMIBC), according to a study published online Nov. 30 in JAMA Network Open.

Marilyn L. Kwan, Ph.D., from Kaiser Permanente Northern California in Oakland, and colleagues examined associations of use of tobacco (cigarettes, pipes, and cigars), e-cigarettes, and marijuana with the risk for recurrence and progression of NMIBC. The analysis included 1,472 patients with NMIBC diagnosed from 2015 to 2019 and followed for 26.4 months.

The researchers found that longer cigarette smoking duration and more pack-years were associated with a higher risk for recurrence in a dose-dependent manner, with the highest risks for patients who had smoked for ≥40 years (hazard ratio, 2.36) or ≥40 pack-years (hazard ratio, 1.97). Recurrence risk was not associated with having ever smoked, being a former or current cigarette smoker, and years since quitting smoking.

Furthermore, there were no associations observed for pipes, cigars, e-cigarettes, or marijuana. Just over half of 102 patients offered a smoking cessation intervention (53.8 percent) received an intervention after diagnosis. Female patients were more likely than male patients to participate in such interventions (76.7 versus 44.7 percent).

"Cigarette smoking remains a critical exposure before and after diagnosis in survivors of NMIBC," the authors write.