MONDAY, May 6, 2019 (HealthDay News) -- If you're an older woman who smokes, quitting may bring a health benefit you haven't considered: A new study suggests it lowers your risk of bladder cancer.
The largest decline in risk was in the first 10 years after quitting, with a modest but steady decline in following years.
Bladder cancer is fairly rare -- about 4.6% of new cancer cases in 2019 -- but is the most common type of urinary system cancer. It often recurs and it has a significant death rate, according to study author Dr. Yueyao Li, a Ph.D. candidate in the School of Public Health at Indiana University in Bloomington.
While bladder cancer is more common in men, women often have worse outcomes even when diagnosed at similar stages.
Smoking is a known risk factor, but findings about the link between how long it's been since a person quit and reduction in bladder cancer risk have been inconsistent.
In this study, Li's team examined data from about 144,000 participants in the Women's Health Initiative, a long-term study of postmenopausal women in the U.S.
Of those, 52.7% never smoked; 40.2% were former smokers and 7.1% were current smokers.
As of Feb. 28, 2017, there had been 870 cases of bladder cancer among the women. Compared to those who never smoked, former smokers had twice the risk of bladder cancer and current smokers had more than triple the risk.
Researchers found a 25% reduction in risk among former smokers in the 10 years after they quit, and it continued to fall more slowly after that. But even 30 years after quitting, ex-smokers still had a higher risk of bladder cancer than women who never smoked.
Compared with current smokers, former smokers had a 39% decrease in bladder cancer risk, which continued to fall over time.
The study was recently published in the journal Cancer Prevention Research.
"Our study emphasizes the importance of primary prevention (by not beginning to smoke) and secondary prevention (through smoking cessation) in the prevention of bladder cancer among postmenopausal women," Li said in a journal news release.
"Current smokers should be advised to quit smoking in order to reduce the risk of bladder cancer," she added.
The American Cancer Society has more on bladder cancer.