Smokers at Greater Risk of Bladder Cancer than Previously Estimated ► NCI Cancer Bulletin for September 6, 2011 - National Cancer Institute

Smokers at Greater Risk of Bladder Cancer than Previously Estimated

Current cigarette smokers have a higher risk of bladder cancer than previously reported, and the proportion of bladder cancers due to smoking in women is now comparable to that in men, according to a study by researchers in NCI’s Division of Cancer Epidemiology and Genetics (DCEG). Their findings were published August 17 in JAMA.
This latest study included data from more than 450,000 participants in the NIH-AARP Diet and Health Study, a questionnaire-based study that began in 1995, with follow-up through the end of 2006.
“Current smokers in our study had a fourfold excess risk of developing bladder cancer, compared to a threefold excess risk observed in previous studies,” said study co-author Dr. Neal Freedman. “The stronger association between smoking and bladder cancer is possibly due to changes in cigarette composition or smoking habits over the years.”
In the current study, former smokers were twice as likely to develop bladder cancer than those who never smoked. As with many other smoking-related cancers, the risk of bladder cancer fell after people quit smoking.
Previous studies had indicated that only 20 to 30 percent of bladder cancer cases in women were caused by smoking, but the new data indicate that smoking is responsible for about half of bladder cancer cases among women, a proportion similar to that found in men in this and previous studies.
The increase in the proportion of smoking-induced bladder cancer cases among women may be because smoking rates in men and women are now similar. The majority of the earlier studies were conducted at times or in places where smoking was much less common among women than men.
“Our findings provide additional evidence of the importance of preventing smoking initiation and promoting cessation for both men and women,” said senior author Dr. Christian Abnet.
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