**1. Introduction**

Gastroesophageal reflux disease (GERD) is accepted as a cornerstone etiological factor for Barrett's esophagus (BE), which is a major predisposition to esophageal adenocarcinoma.

GERD is a precursor to BE, which represents intestinal metaplasia (IM), [1] and the latter is most likely a precursor to esophageal cancer. Progression from Barrett's to dysplasia is estimated to be in about 20% of cases [2]. Chronic heartburn can progress to Barrett's, so EGD (esophagogastroduodenoscopy) is recommended every 5 years for these cases, but also for cases taking medication for chronic GERD [3].

BE is a condition in which there is an abnormal change (metaplastic tissue) with the replacement of multilayered epithelial cells, under the long-term influence of gastroesophageal reflux, with specialized intestinal cells that are present only in the small and large intestines. This change is considered to be a precursor of distal malignancy of the esophagus as it is associated with a high incidence of further transition to adenocarcinoma of the esophagus, with a highly malignant nature [1, 2].

BE is diagnosed with endoscopy: we encounter inflammatory, erosive, ulcerative changes up to narrowing of the distal lumen of the esophagus, classified according to Los Angeles A-D, followed by microscopic examination of the tissue from the affected area from the biopsies obtained. BE cells are classified into four categories: nondysplastic (such as incomplete and complete intestinal metaplasia), low-grade dysplasia, high-grade dysplasia, and carcinoma.

Up to the level of low dysplasia, the changes can be treated with PPI, including here the fundoplication according to Nissen. High-grade dysplasia and early stages of adenocarcinoma can be treated with endoscopic resection or radiofrequency ablation [1]. Later stages of adenocarcinoma can be treated by surgical resection. Nondysplastic or low-grade (LGD) cases are managed by annual surveillance with endoscopy or treatment with radiofrequency ablation. It should be borne in mind that in cases with high-grade dysplasia (HGD), the risk of developing cancer can be 10% per patient-year or more, so treatment is needed as soon as possible [4].

A greater extent of dysplasia has a significantly higher risk of cancer as well as the presence of an endoscopic abnormality [5].

BE is thought to be an adaptation to the chronic exposure of acid reflux, but also of another nature, in the esophagus for a long time [6].
