A cohort study of stomach cancer in a high-risk American population.

Demographic, smoking and dietary information was obtained from a cohort of 17,633 white American men, largely of Scandinavian and German descent, who responded to a mailed questionnaire in 1966. After 20 years of follow-up, 50% to 90% increases in mortality from stomach cancer (75 deaths) were found among foreign-born, their children, and among residents of the North Central states. An association was seen with low educational attainment and laboring or semiskilled occupations, primarily among immigrants and their children. Risk was evaluated in subjects who regularly smoked cigarettes (RR = 2.6, 95% CI = 1.1 to 5.8). A significant dose-response trend was observed, with subjects who smoked 30 or more cigarettes per day having more than a five-fold increased risk compared with those who never smoked. Elevated risks were also found for pipe smoking and smokeless tobacco use, but not for alcohol consumption. Analysis of dietary consumption of nine food groups revealed no significant associations with stomach cancer. However, total carbohydrate intake and a few individual food items (salted fish, bacon, cooked cereal, milk, and apples) were associated with increased risk. The findings of this prospective study of a high-risk population add to the limited evidence relating tobacco consumption to stomach cancer risk and suggest clues to ethnic, geographic, and dietary risk factors.