Abstract B84: Prospective study of self-reported diabetes and risk of upper gastrointestinal cancers

Abstract

Abstract While gastric non-cardia adenocarcinoma (GNCA) incidence rates in the United States have decreased, the rates of gastric cardia adenocarcinoma (GCA) and esophageal adenocarcinomas (EADC) have increased. Obesity increases the risks of GCA and EADC, and the associations may be partially mediated by insulin resistance. A few case-control studies have shown an association between diabetes and an increased risk of EADC. We examined the association between self-reported diabetes and GCA, GNCA, EADC, and esophageal squamous cell carcinoma (ESCC) in a prospective cohort of approximately 500,000 people in the United States, ages 50-69 at baseline, using Cox proportional hazards regression to estimate the hazard ratios (HR) and 95% confidence intervals (CIs), controlling for multiple potential confounders. In contrast with previous case-control studies, the results of our prospective analysis showed no association with risk of EADC, HR (95% CI) = 0.98 (0.73-1.31). Furthermore, self-reported diabetes showed no association with ESCC, HR (95% CI) = 1.02 (0.60-1.74), or GNCA, HR (95% CI) = 0.98 (0.70-1.37). However, diabetes was significantly associated with an increased risk of GCA, HR (95% CI) = 1.89 (1.43-2.50). The association between diabetes and risk of GCA remained after adjustment for body mass index (BMI), HR (95% CI) = 1.70 (1.28-2.26). Analyses stratified on World Health Organization BMI categories yielded similar estimates. Our results suggest that the metabolic and hormonal changes related to diabetes may play an important role in the etiology of GCA independently from BMI. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B84.