Bladder cancer risk factors

Risk factors
Exposure to environmental carcinogens of various types is responsible for the development of most bladder cancers. Tobacco use (specifically cigarette smoking) is thought to cause 50% of bladder cancers discovered in male patients and 30% of those found in female patients. Thirty percent of bladder tumors probably result from occupational exposure in the workplace to carcinogens such asbenzidine. Occupations at risk are metal industry workers, rubber industry workers, workers in the textile industry and people who work in printing. Some studies also suggest that auto mechanics have an elevated risk of bladder cancer due to their frequent exposure to hydrocarbons and petroleum-based chemicals.

Hairdressers are thought to be at risk as well because of their frequent exposure to permanent hair dyes. It has been proposed that hair dyes are a risk factor, and some have shown an odds ratio of 2.1 to 3.3 for risk of developing bladder cancer among women who use permanent hair dyes, while others have shown no correlation between the use of hair dyes and bladder cancer. Certain drugs such ascyclophosphamide and phenacetin are known to predispose to bladder TCC. Chronic bladder irritation (infection, bladder stones, catheters, bilharzia) predisposes to squamous cell carcinoma of the bladder. Approximately 20% of bladder cancers occur in patients without predisposing risk factors. Bladder cancer is not currently believed to be heritable (i.e., does not "run in families" as a consequence of a specific genetic abnormality). [This statement contradicts contents in the section that follows]