Barrett esophagus and cancer: pathogenesis, carcinogenesis, and diagnosticdilemmas

A metaplastic process, in which native squamous epithelium of the distal es ophagus is replaced by columnar epithelium, is known as Barrett esophagus ( BE). Over the past years, intestinal metaplasia was recognized as a marker for BE. The risk for the development of esophageal adenocarcinoma in a pati ents with BE is much higher when compared to the normal population. Duodeno -gastro-esophageal reflux is supposed to play a role in the pathogenesis of BE and rising incidence of adenocarcinoma of the esophagus. With current t herapeutic options, when clinical manifestation of this cancer occurs, it i s too late for cure in the majority of patients. Therefore, attention shoul d be focused on early diagnosis, for which molecular genetic techniques mig ht become available. Current data on genetic alterations involved in carcin ogenesis of BE are discussed. Grading of dysplasia in BE carries important clinical consequences for the individual patient: intensification of endosc opic surveillance or 'prophylactic esophagectomy'. Several morpho- and/or c ytometric parameters may be used for discrimination between different grade s of dysplasia in BE. Therefore, a new and original algorithm for the poten tial application of quantitative pathology in grading of dysplasia in patie nts with BE has been proposed. Molecular biology together with image analys is of histological spectrum of BE enable better understanding of the mechan isms of malignant degeneration and might ultimately lead to targeted cancer prevention and/or therapeutic interventions.