(HealthDay News) — Among postmenopausal women, former smokers have a reduced risk for bladder cancer within the first 10 years of cessation, which continues to decline over time but remains elevated compared with never smokers, according to a study published in the May issue of Cancer Prevention Research.
Yueyao Li, M.D., from Indiana University in Bloomington, and colleagues examined the dose-response relationship between years since quitting and the risk for bladder cancer. Data were included for 143,279 postmenopausal women from the Women’s Health Initiative Study.
During an average of 14.8 years of follow-up, the researchers identified 870 bladder cancer cases. After adjustment for pack-years of smoking, within the first 10 years of cessation, bladder cancer risk among nonsmokers declined by 25 percent and continued to decline as cessation time increased; however, after 30 years of quitting, the risk remained higher than among never smokers (hazard ratio, 1.92). Compared with current smokers, smokers who quit had a lower risk for bladder cancer (hazard ratio, 0.61).
“The study indicates the importance of primary prevention as well as the importance of smoking cessation,” the authors write. “Further studies examining the underlying mechanisms of relationships between smoking and bladder cancer, and studies exploring the relationships between smoking cessation and other subtypes of bladder cancer are likely to further our understanding of this issue.”
One author disclosed financial ties to Achieve Life Services and received donated smoking cessation medications from the manufacturer.