Geographic patterns of bladder cancer in the United States

Age-adjusted rates of mortality during 1950-69 from bladder cancer were correlated with demographic and industrial indexes for the 3,056 counties of the contiguous United States. Rates among whites and nonwhites of both sexes rose sharply with urbanization. A small but positive socioeconomic gradient was observed, and mortality was slightly higher among males in counties with high percentages of British and German residents. Even after controlling for demographic variables, the Northeastern excess of bladder cancer among whites was sizable, whereas the regional differences among nonwhites were small. The high rates in the Northeast were seen in both sexes and in rural as well as urban areas, with mortality in small counties in upstate New York and New England equaling or exceeding those in large metropolitan centers elsewhere in the country. Outside the Northeast, high rates were generally limited to urban areas, but clusters of elevated mortality occurred among white males along the Illinois-Wisconsin border, in parts of lower Michigan, and in southern Louisiana. Industrial factors may explain at least part of the geographic clustering, inasmuch as rates among males were significantly higher in U.S. counties where the chemical industry is heavily concentrated. Increases were also associated with the printing industry, but correlations with 16 other major manufacturing industries were near or below expected levels.