Occupational Risk Factors for Gastric Cancer: an Overview

To date, most epidemiologic studies of gastric cancer have focussed on diet and lifestyle factors (1-4). However, numerous cohort studies, occupational surveys, and a few case-control studies have reported associations between gastric cancer risk and various occupations, such as carpenters and construction workers (5, 6), quarrymen and stone cutters (6), coal (7) and metal miners (8, 9), rubber workers (10, 11), farmers (6, 12, 13), furniture workers (14), fishermen, sailors, and seamen (5, 6, 15), pesticide applicators (16), chemical and petrochemical workers (6, 17-19), machinists (6, 20), and asbestos workers (21). Many of these occupations have significant exposures to suspected gastric cancer risk factors including asbestos, mineral dusts, N-nitroso compounds, and nitrogen oxides. A correlation has been observed between gastric cancer risk, educational level, and social class determined from occupation (22). This and inconsistencies across studies for some occupations has led some authors to the conclusion that confounding by dietary or other factors associated with low social class may explain most of the occupational associations (23-26). This presentation reviews the epidemiologic evidence for a role of occupational exposures in gastric cancer etiology. First, the results from several large surveys of occupation and cancer will be discussed. Second, the epidemiologic literature concerning specific exposures suspected to increase gastric cancer