And, though women were thought to have a lower rate of smoking-attributable bladder cancer than men, it now appears that smoking accounts for half of all cases in both men and women. These findings were recently reported in the Journal of the American Medical Association.
One of the most important risk factors for bladder cancer is smoking. Previous studies suggested that smoking was linked with a three-fold increase in risk of bladder cancer. These studies also found that 20 to 30 percent of bladder cancers in women and roughly 50 percent of bladder cancers in men were caused by smoking. Changes in smoking habits and the composition of cigarettes, however, may cause these numbers to shift.
To evaluate more recent data regarding smoking and bladder cancer, researchers at the National Cancer Institute used the NIH-AARP Diet and Health Study. Information was available about more than 450,000 people for the period from 1995 through 2006.
- Smoking accounted for a higher proportion of bladder cancer among women than previously reported: Roughly half of all bladder cancers among women were attributable to smoking, which is similar to what is seen among men.
- Current smokers had a four-fold increase in risk of bladder cancer, which is higher than previous estimates.
- Risk of bladder cancer was lower among former smokers than among current smokers. Nevertheless, the risk of bladder cancer in former smokers was twice as high as the risk in people who had never smoked.
The study highlights the important role that smoking plays in bladder cancer among both men and women. Never-smokers have the lowest risk, but current smokers can reduce their risk by quitting.
It’s also important to be aware that roughly half of all bladder cancers are due to factors other than smoking. This means that everyone (regardless of smoking status) should seek care for symptoms of bladder cancer such as blood in the urine.
Reference: Freedman ND, Silverman DT, Hollenbeck AR, et al. Association between smoking and risk of bladder cancer among men and women. JAMA. 2011;306(7):737-745. doi:10.1001/jama.2011.1142