Columnar-lined (Barrett's) esophagus

Barrett's esophagus can be found in 10% to 15% of patients who have endoscopic examinations because of symptomatic gastroesophageal reflux disease. For every case identified by a physician, there are approximately 20 cases in the general population that go unrecognized. Physiologic abnormalities predisposing to severe gastroesophageal reflux disease are found frequently in patients with Barrett's esophagus and include extreme lower esophageal sphincter incompetence, abnormal esophageal motility, gastric acid hypersecretion, duodenogastric reflux, and diminished esophageal pain sensitivity. The abnormal epithelium regresses infrequently, if ever, with either medical or surgical therapy, and even a successful antireflux operation does not eliminate the risk of adenocarcinoma in Barrett's esophagus. Although most cases are due to gastroesophageal reflux disease, Barrett's epithelium has been found to develop in approximately two thirds of patients who receive chronic CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy for breast cancer, presumably as a result of CMF-induced esophagitis.