[Preventive operations of the gastrointestinal tract in precancerous conditions].

Precancerous conditions are characterized by an increased epidemiological cancer risk, precancerous lesions by a histopathological abnormality (epithelial dysplasia). Adenomas are typical examples of this in the GI tract and therefore must be removed by endoscopy or surgery. The extent of the procedure is dictated by size, growth pattern and histology. The Barrett oesophagus, chronic atrophic gastritis type B, colorectal adenomas and familial adenomatous polyposis are the most frequent serious conditions.