Self-reported goiter is associated with a significantly increased risk of gastric noncardia adenocarcinoma in a large population-based Chinese cohort

Iodine is concentrated by the gastric mucosa, where it may act as an antioxidant. Therefore, iodine deficiency, and its sequelae goiter, may be associated with an increased risk of gastric cancer. We examined the association between self-reported goiter and upper gastrointestinal cancer in a Chinese cohort of 29,584 adults. Using multivariate adjusted Cox models, we found goiter associated with a significantly increased risk of gastric noncardia adenocarcinoma, HR (95% CI) 2.04 (1.01, 4.11) and nonsignificantly with gastric cardia adenocarcinoma, HR (95% CI) 1.45 (0.91, 2.30). We also found a borderline, insignificant increased risk of esophageal squamous cell carcinoma, HR (95% CI) 1.37 (0.97,1.94). Our findings are consistent with the hypothesis that iodine deficiency is associated with an increased risk of gastric cancer.