The cause of bladder cancer is not known. But what is known is that certain risk factors are linked to the disease. Anything that increases a person's chance of developing a disease is called a risk factor. Some risk factors, such as smoking, can be controlled. Others, like a person's age, gender, or race, can't be changed. But having a risk factor, or even several, doesn't mean that a person will get the disease.

Some of these risk factors for bladder cancer are as follows:

• Smoking: Smoking is the most important risk factor for bladder cancer. Bladder cancer occurs 2 to 4 times more frequently in smokers than it does in nonsmokers, and some experts believe that smoking causes up to 50% of bladder cancer in men. Cancer-causing chemicals in tobacco smoke are absorbed from the lungs and get into the blood. From the blood, they are filtered by the kidneys and collect in the urine. These chemicals in the urine damage the cells that line the inside of the bladder and increase the risk of cancer. The risk of developing bladder cancer decreases if one stops smoking. However, even 10 years after quitting smoking, an ex-smoker still has a higher risk of developing bladder cancer than a never-smoker.
• Age: The risk of developing bladder cancer increases with age. Most new cases in both men and women occur in people aged 60 years and older.
• Race: Bladder cancer occurs nearly twice as often in whites than in blacks; however, black people who develop bladder cancer are approximately twice as likely as whites to die from the disease. Blacks are also diagnosed at more advanced stages of bladder cancer than whites, according to the National Cancer Data Base Report and other research. More than twice as many blacks (10.9%) as whites (5.4%) diagnosed with bladder cancer receive no treatment for their disease, which may also play a role.
• Sex: Bladder cancer is four times more likely to be diagnosed in men than in women; however, women who develop bladder cancer are more likely to die from the disease than men. A greater percentage of females are diagnosed at more advanced stages than men, which may contribute to the higher mortality rate in women. Other factors contributing to the higher death rate may include the relative thinness of the elderly adult female bladder, which perhaps permits more rapid spread of the cancer, or the older median age at diagnosis in women than men.
• Work related: Other risk factors for bladder cancer include chemicals used in making dyes, rubber, leather, and textiles. People who work at dry cleaners, paper manufacturers, rope and twine makers, and workers in clothing production have a greater chance of developing bladder cancer.
• Other risk factors: Chronic bladder irritations such as urinary infections and kidney and bladder stones don't cause bladder cancer, but they have been linked to bladder cancer in some studies. People who have had bladder cancer have a higher risk of getting another tumor. If a member of your family has had bladder cancer, you are at higher risk. Cyclophosphamide (a chemotherapy drug) and radiation therapy directed at the pelvis have been noted as risk factors in some research. Very rarely, a connection between the belly button and the bladder fails to disappear as it should before birth and can become cancerous. Use of the Chinese herb, Aristocholia Fangchi, taken by some people to help them lose weight, has been linked to bladder cancer.