Etiopathogenesis, diagnosis and treatment of Barrett's esophagus: modern views. Part 1

In the first part, it was noted that Barrett’s esophagus (PB) is a disease characterized by the replacement of a multilayer squamous epithelium with a metaplastic columnar epithelium. Taking into account modern ideas and accumulated clinical research data, the British Society of Gastroenterology in 2014 proposed a definition of Barrett’s esophagus based only on the description of metaplastic changes in the esophagus without taking into account their precancerous status. According to the authors, such a descriptive approach makes it possible not to focus on the traditional question of the risk of developing cancer in various types of metaplasia. However, after the diagnosis of Barrett’s esophagus, the risk of developing cancer should be determined individually in accordance with endoscopic, pathomorphological and molecular data. It is shown that, in accordance with the recommendations of the British Society of Gastroenterologists, Barrett’s esophagus refers to a pathological condition in which part of the normal flat epithelium of the mucosa of the distal esophagus is replaced by a metaplastic cylindrical epithelium, which is reliably determined by endoscopic examination (that is, larger than 1 cm) above the esophageal-gastric junction and morphologically verified. It follows from this definition that endoscopic and histological studies are the basis for the correct diagnosis of this pathological condition, and subsequent comparison of endoscopic and histological data allows us to determine the degree of changes in the mucous membrane and the risk of esophageal adenocarcinoma and, as a consequence, the tactics of treatment and management of patients.