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An increased risk for carcinomas of the digestive tract was recently established in a retrospective cohort study of over 38,000 patients with CF (115). Lesions included cancers of the esophagus, stomach, small bowel, colon, liver, biliary tract, pancreas, and rectum. The authors postulated that the increased risk of malignancy may be partly explained by differential localization and expression of the cystic fibrosis transmembrane regulator gene. Other explanations included ancillary effects of CF such as Barrett esophagus, the association of hepatobiliary tract malignancies with gallstones, increased gut epithelial cell turnover, antioxidant deficiencies resulting from persistent malabsorption, and steatorrhea, which has been associated with small bowel cancer in patients with celiac disease (116).