RISK FACTOR INFORMATION FOR SELECTED CANCER TYPES

Bladder Cancer

The American Cancer Society estimates that bladder cancer will affect 87,500 people in the U.S. in 2001, accounting for 6% of all cancers diagnosed  in  the  United  States  among  men  and  2% among women (ACS, 2001).  In Massachusetts, the  1997 age-adjusted incidence rate of this cancer was 14.1 per 100,000 residents (MCR, 2000).  Males are three times more  likely  to develop bladder cancer than females and whites are two times more likely to develop this disease than blacks.  The risk of bladder cancer increases with age and the mean age at diagnosis is 68-69 years (ACS, 2000).

The greatest risk factor for bladder cancer is cigarette smoking.  Smokers are more than twice as likely to develop bladder cancer compared to nonsmokers (ACS, 2000).  The risk of developing bladder cancer increases with the number of packs smoked per day and with duration of smoking. Further, the risk of bladder cancer may be higher in women than in men who smoke comparable numbers of cigarettes (Castelao et al., 2001).   Approximately 25-60% of all bladder cancers can be attributed to tobacco use (Johansson and Cohen, 1997).  Smoking cessation has been found to reduce the risk of developing bladder cancer by 30% to 60% (Silverman et al., 1996).

Studies have also revealed a number of occupations that are associated with bladder cancer.  In fact,  exposures  to chemicals in the workplace account for an estimated 20-25% of all bladder cancers diagnosed among men in the U.S. (Johansson and Cohen, 1997).  Occupational exposure to aromatic amines, such as benzidine and 2-naphthylamine, increases the risk of bladder cancer (ACS, 2000).   These chemicals were common in the dye industry in the past.  A higher risk of bladder cancer has also been observed among aromatic amine manufacturing workers as well as among workers in the rubber, leather, textiles, printing, and paint products industries (ACS, 2000; Silverman et al., 1996).  The development of new chemicals, changed worker exposures, and the elimination of many known bladder carcinogens in  the  workplace have caused shifts in those occupations  considered  to be high risk.  For  example, risks among dye, rubber, and leather workers have declined over time, while other occupations such as motor vehicle operation (e.g., drivers of trucks, buses, and taxis) and the aluminum industry have emerged as potential high-risk occupations  (Silverman  et  al.,  1996).     However,  specific  occupational  exposures  in  these occupations have not been confirmed and study findings are not consistent.   Further, the risk of bladder cancer from occupational exposures may be increased among smokers (ACS, 2000).

Dietary factors such as consumption of fried foods as well as foods high in fat and cholesterol have been found to be associated with increased bladder cancer risk (Silverman et al., 1996).  Use of the Chinese herb,  Aristocholia fangchi,  found  in  some  dietary supplements, has also been linked with bladder cancer (ACS, 2000).  Use of some anti-cancer drugs (e.g., cyclophosphamide and chlornaphazine), use of phenacetin, and infection with Shistosoma haematobium (a parasite found in Africa) are thought to be associated with the development of bladder cancer, however, not all epidemiological studies have produced convincing findings (Silverman et al., 1996).

Other risk factors for bladder cancer include a  personal history of bladder cancer, certain rare birth defects involving the bladder, and exposure to ionizing radiation (ACS, 2000; Silverman et al., 1996).  Exposure to chlorinated by-products  in drinking water has also  been  suggested  to increase bladder cancer risk, however, a recent population-based study found that an association was present only among smokers (Cantor et al., 1998).

References

Source: Community Assessment Unit, Bureau of Environmental Health Assessment, Massachusetts Department of Public Health
July, 2001

RISK FACTOR INFORMATION FOR SELECTED CANCER TYPES

American Cancer Society. 2001. Cancer Facts & Figures 2001.  Atlanta: American Cancer Society, Inc.

American Cancer Society. 2000. Bladder Cancer. Available at: http://www3.cancer.org/cancerinfo/.

Cantor KP, Lynch CF, Hildesheim ME, et al. 1998. Drinking water source and chlorination by-products I. Risk of bladder cancer. Epidemiology 9(1):21-28.

Castelao JE, Yuan JM, Skipper PL, et al. 2001. Gender- and smoking-related bladder cancer risk. J Natl
Cancer Inst 93(7):538-45.

Johansson SL, Cohen SM. 1997. Epidemiology and etiology of bladder cancer. Semin Surg Oncol 13:291-
298.

Massachusetts Cancer Registry. 2000. Cancer Incidence and Mortality in Massachusetts 1993-1997: Statewide Report. March 2000. Massachusetts Department of Public Health, Bureau of Health Statistics, Research and Evaluation, Massachusetts Cancer Registry. Boston, MA.

Silverman D, Morrison A, Devesa S. Bladder Cancer. In: Cancer Epidemiology and Prevention. 2nd Ed, edited by Schottenfeld D,  Fraumeni. JF. New York:  Oxford Press University: 1996.

Source: Community Assessment Unit, Bureau of Environmental Health Assessment, Massachusetts Department of Public Health
July, 2001