Pathophysiology and investigation of Barrett's esophagus

Barrett's esophagus is an acquired condition with columnar metaplasia of the distal esophagus. Gastroesophageal reflux is the main pathophysiological factor, although genetic predisposition may play a role. The significance of Barrett's esophagus is that it is the only recognized risk factor for adenocarcinoma of the esophagus, which is one of the most rapidly rising types of cancer in North America. Cancer develops in Barrett's esophagus through a series of steps including mucosal dysplasia. High grade dysplasia is clearly a premalignant lesion and has been the focus of endoscopic surveillance strategies. Because dysplasia and adenocarcinoma develop predominantly in patients with specialized intestinal columnar epithelium, they make up the group that would be considered for surveillance programs. Endoscopic surveillance for dysplasia is only indicated for patients in whom esophagectomy would be considered if high grade dysplasia or carcinoma was found, at least until other endoscopic ablative techniques are proven to be beneficial. It has been recommended that endoscopy be performed every other year and be increased to yearly if low grade dysplasia is found. High grade dysplasia should be confirmed by another expert pathologist, and the patient should then be considered for esophagectomy. Flow cytometry and genetic markers may improve the ability to select patients for surveillance programs in the near future.