What Are the Causes of Bladder Cancer?

The exact cause of bladder cancer is not known. But like other types of cancer, bladder cancer develops when the body rapidly makes unneeded cells. These out-of-control cells grow on the lining of the bladder wall and can become cancerous.

Bladder cancers are not known to result from inherited mutations (changes) in certain genes. But some people seem to inherit a reduced ability to break down certain types of chemicals that are known to cause cancer. These people appear to be more sensitive to the cancer-causing effects of tobacco smoke and certain industrial chemicals. Researchers are developing tests that may help identify such people, but these tests are not generally available yet.

Risk Factors for Bladder Cancer

Doctors and researchers believe that certain factors, known as risk factors, increase a person’s chances of getting bladder cancer. However, not everyone with a risk factor will develop bladder cancer. Also, people without risk factors can develop the disease.

Risk factors for bladder cancer include:

• Cigarette smoking - Cigarette smoking is a major risk factor for developing bladder cancer. Bladder cancer occurs in smokers twice as often as nonsmokers. Quitting smoking reduces the risk of bladder cancer, as well as several other types of cancer and diseases.
• Occupational exposure - The risk of bladder cancer appears to be higher for people who are exposed to dyes and some chemicals at work, especially in the rubber, chemical, leather, textile, metal, and printing industries.

• Chronic bladder irritation - Chronic bladder infections or bladder stones may be linked to certain types of bladder cancer.
• Age - The risk for bladder cancer increases with age. More than 70 percent of people with bladder cancer are older than 65 and this disease is rare in people under 40.
• Gender - Bladder cancer occurs about four times more often in men than in women.
• Race - Caucasians are twice as likely to develop bladder cancer as African-Americans and Hispanics. Asians have the lowest bladder cancer rates.
• Personal history of cancer - People who have had bladder cancer previously have a higher risk of developing the disease again.
• Chemotherapy - People who were treated with high doses of certain kinds of chemotherapies for cancer are more likely to get bladder cancer.
• Family history of bladder cancer - People with family members who have had bladder cancer are more likely to develop the disease. In addition, people with a mutation of the retinoblastoma gene, which causes cancer of the eye in infants, have a higher rate of bladder cancer. Furthermore, people who inherit genes that lead to slow breakdown of chemicals are also more likely to develop bladder cancer.
• Parasite infections - Infection with certain parasites found in tropical regions of the world, but not in the United States, increases the risk of bladder cancer.
• Birth defects - A connection between the belly button and the bladder known as the urachus usually disappears before birth. If some of the urachus is still there after birth, it can become cancerous. In exstrophy, another birth defect, the skin, muscle, and connective tissue in front of the bladder do not close completely. This makes it easier for the bladder to become infected and this condition can eventually lead to bladder cancer.
• Arsenic in drinking water - People whose drinking water contains high levels of arsenic are more likely to develop bladder cancer.
• Not drinking enough fluids - People who drink a lot of fluids every day have a lower risk of bladder cancer, probably because they empty their bladders often and this stops chemicals from staying in their body.
• Pelvic radiation - People who receive pelvic radiation are at greater risk for bladder cancer.This content has been reviewed and approved by Myo Thant, MD.