Older women should quit smoking to reduce bladder cancer risk, study says
Smoking cessation appears to confer benefits for bladder cancer in older women, with a recent study suggesting a 25-percent risk reduction.
The study included 143,279 postmenopausal women from the Women's Health Initiative Study. Of these, 75,458 (52.67 percent) were never smokers, 57,606 (40.21 percent) were former smokers and 10,215 (7.13 percent) were current smokers.
Compared with never smokers, former smokers were slightly younger, more likely to be non-Hispanic White, tended to have lower body mass index (BMI), hold higher degrees, work in managerial or professional fields, were more likely to be divorced or separated, have a higher rate of family history of cancers, to be current drinkers, and have low fat dietary intake.
Bladder cancer occurred in 870 women over an average follow-up of 14.8 years: 308 women in the never-smoker group, 458 in the former-smoker group and 104 in the current-smoker group.
Multivariable Cox proportional hazards regression models showed that the risk of incident bladder cancer decreased by 25 percent within the first 10 years of cessation, with the risk reduction becoming greater as cessation time increased. However, the risk remained higher than that observed in never smokers after 30 years of quitting (hazard ratio [HR], 1.92; 95 percent CI, 1.43–2.58).
Meanwhile, relative to current smokers, those who quit smoking had about a 40-percent lower risk of bladder cancer (HR, 0.61; 0.40–0.94).
The present data highlight the importance of smoking cessation in the primary prevention of bladder cancer, researchers said. Postmenopausal women who smoke should be advised to quit smoking in order to reduce their risk.
Additional studies are needed to elucidate the underlying mechanisms of the association between smoking and bladder cancer, as well as to explore the relationships between smoking cessation and other subtypes of bladder cancer.