WOMEN WHO smoke are far more at risk of developing bladder cancer than previously realised, according to new research from the United States. Smoking is now implicated in half of all bladder cancers detected in women.
This latest study by the US National Institutes of Health included information from more than 450,000 individuals.
Earlier studies had suggested that between 20 and 30 per cent of bladder cancer cases in women could be attributed to smoking but the figure is actually much higher according to the researchers who published the details yesterday evening in the Journal of the American Medical Association.
Cigarettes are the single biggest risk factor in bladder cancer, according to the Irish Cancer Society. The risk arises because chemicals in the smoke pass through the system to damage the sensitive cells that line the bladder.
The discrepancy when comparing earlier studies with this latest research work arose because of increases in smoking by women, the US team said.
Most of the earlier studies were done at times or in regions where smoking was much less common among women, they write.
The stronger link between smoking and bladder cancer may also arise because of changes in cigarette composition or smoking habits, according to Dr Neal Freedman of the National Cancer Institute.
It means that while smoking rates have decreased overall, incidence rates of bladder cancer have not seen a corresponding decline, he said.
Even though men and women who smoke face similar risks of bladder cancer, men are still four times more likely than women to be diagnosed with it. About 400 cases of bladder cancer in total were recorded here in 2007, the society said.
The US study showed former smokers were twice as likely to develop bladder cancer as those who had never smoked, and current smokers faced a fourfold increased risk. Quitting smoking helped to lower the risk, however, particularly if the cessation is sustained.
“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.
The risk of bladder cancer increases with age, the society said. Symptoms include blood in the urine and pain while passing urine.
Those concerned about cancer or who want information on symptoms can contact the Irish Cancer Society on its freephone helpline: 1800-200-700.