Nutrient patterns and risk of squamous cell carcinoma of the esophagus: A factor analysis in Uruguay

Background: Squamous cell carcinoma of the esophagus is a common disease, with an age-standardized incidence rate of 55 cases per 100,000 persons in the northern counties of Uruguay. These rates are comparable to those observed in Iran and China. Materials and Methods: In order to contribute to the clarification of the etiology of this lethal disease, a case-control study which included 234 cases and 936 controls, frequency matched for age, sex and residence, was conducted. Factor analysis (principal components) was conducted on the controls and three factors were retained, high-fat, carbohydrates and antioxidants. These nutrient patterns were submitted to multiple logistic unconditional regression in order to estimate the odds ratios of esophageal cancer. Results: The nutrient patterns (labeled as high-fat, carbohydrates and antioxidants) were significantly associated with the risk of esophageal squamous cell cancer. Whereas the high-fat and carbohydrates patterns were directly associated with an increased risk of esophageal cancer, the antioxidants pattern was strongly protective (OR 0.39, 95% CI 0.23-0.66). Conclusion: In squamous cell carcinoma of the esophagus an antioxidant dietary pattern is protective, probably due to its action against oxidative stress while high-fat and carbohydrates patterns are associated with an increased risk which may be due to the meat and sodium content, respectively.