Cancer in Utah: risk by religion and place of residence.

We compared cancer incidence during 1967--75 between Mormons and non-Mormons living in urban and rural areas of Utah. The non-Mormon urban men had a 34% higher risk of cancer compared with their rural counterparts. Most of this increase in risk occurred in sites associated with tobacco and for cancers of the stomach, colon, and prostate gland. Urban Mormon males had no significant increase in risk. The urban female population was at higher risk than was the rural regardless of religion. The increase was not as striking as that observed in non-Mormon men (8 vs. 34%); cancers of the respiratory and gastrointestinal tracts and female genitalia contributed to the elevated risk. We concluded that personal habits such as smoking and drinking and reproductive factors were possible explanations for the previously observed urban-rural gradients in cancer risk.