Geographic patterns of large bowel cancer in the United States.

Age-adjusted rates of mortality from colon and rectal cancer during 1950-69 were correlated by sex and race (white and nonwhite) with demographic data for the 3,056 counties of the contiguous United States. Mortality was consistently elevated in counties with large populations, higher income and education levels, and high percentages of residents of Irish, German, or Czechoslovak descent. The urban, socioeconomic, and, ethnic factors were each linked to large bowel cancer, but they only partly explained the predominance of this tumor in the Northern United States. A survey was made of the limited data available on dietary habits by region and on alcohol sales by county, but the concomitant variation with bowel cancer mortality rates was not impressive.