Retrospective cohort study of risk-factors for esophageal cancer in Linxian, People's Republic of China

Abstract

A retrospective cohort study of esophageal (including gastric cardia) cancer was conducted to examine dietary and other potential risk factors in Linxian, a high-risk area in P.R. China. Study subjects were identified based on participation in a cytology examination conducted in 1974. They were interviewed in 1989 to obtain information on esophageal cancer risk-factors and identify new cases and deaths. A total of 1,162 subjects from the analytic cohort of 12,693 were determined to have developed esophageal cancer over the 15-year follow-up period. Results indicate that increased age, male gender, a positive family history, low education level, surface-water use, and pork consumption were the strongest risk factors for esophageal cancer identified in this cohort, while use of corn as a primary staple and infrequent consumption of fresh vegetables also were possible risk factors. Traditional or suspected risk factors for esophageal cancer in this and other populations—smoking and alcohol use, and pickled vegetable and moldy food consumption—were not risk factors in this study. Some variation in risk was seen based on the subject's cytology result from 1974. We conclude that dietary factors appear to play a role in the etiology of esophageal cancer in this high-risk population, but are less important than other constitutional factors such as age, gender, and family history.