[Barrett's esophagus. Prevalence, risk of adenocarcinoma, role of endoscopic surveillance].
Review
Overview
abstract
The presence of gastric metaplasia in the distal esophagus is better known as Barrett's Esophagus (BE). It is an acquired condition caused by gastro-esophageal reflux disease and is associated with a high risk of adenocarcinoma development in the distal esophagus and cardia. The definition of BE has changed over the years as only the specialized metaplasia, with the characteristic "goblet cells", has been shown to carry a risk of cancer development. BE is currently defined as the presence of intestinal metaplasia in the distal esophagus. The prevalence of intestinal metaplasia of the distal esophagus in patients undergoing endoscopy with multiple biopsies for dyspeptic symptoms, varies from 9-21% at the level of the cardia and from 1.2-8% at 3 cm above the esophago-gastric junction, with a decreasing caudo-cranial frequency. Among the BE population (intestinal metaplasia 3 or more cm long) there is a prevalence of male sex and white race, with an average age between the 5(th) and 7(th) decade. The risk of BE mucosa advancing to esophageal adenocarcinoma is not well established: incidence rates from 1/52 years-patient to 1/441 years-patient and a calculated risk from 30 to 125 times higher than in the normal population were reported. These discrepancies are probably related to: 1) temporal differences of the studies, 2) retrospective versus prospective type of the studies, 3) length of follow-up, 4) number of individuals surveilled, 5) regional variations. A literature analysis confirmed that the differences are mostly related to the number of patients studied (the larger the population the lower the incidence), are generally inversely proportional to the follow-up length (the shorter the follow-up the higher the incidence) and depend on the type of the studies (the incidence is higher in the retrospective studies than in the prospective one's). Surveillance program: esophageal adenocarcinoma is a lethal tumor with a 20% 5-year survival rate. The guidelines of The American College of Gastroenterology advice a two-year surveillance rate for BE patients without dysplasia. The difficulty with BE surveillance programs-- even if worthwhile on a single patient basis-- is that they are very expensive and at the present none of the endoscopic surveillance prospective studies has shown a positive impact in the survival rate. From our knowledge it doesn't seem wise to abandon a precautionary surveillance strategy, but further studies are needed to better understand the risk population: at the moment our advice is to monitor male patients in good general conditions with a BE segment longer than 3 cm.
