[Clinical aspects of premalignant lesions of the upper gastrointestinal tract].

A variety of somatic genetic and epigenetic aberrations are discussed in the multistep carcinogenesis of tumors of the upper gastrointestinal tract but specific genetic changes are still unknown. Primary prevention of cancer is important and includes the control of causal endo- and exogenous factors. Screening endoscopies to detect premalignant lesions or early carcinoma cannot be recommended in the Western world. The incidence of preinvasive neoplasia, above all the high-grade intraepithelial neoplasia, in Barrett's esophagus or stomach is as low as 4.0 or 0.6%, respectively. Secondary prevention of cancer after changes of the mucosa should be performed by endoscopic diagnosis and treatment performing biopsies or resection of the lesion. After histological diagnosis of a high-grade intraepithelial neoplasia, complete resection of these lesions including complete ablation of Barrett's mucosa should be carried out. On the basis of an exact pathological report, close cooperation between endoscopist and surgeon seems to be necessary to find out the best individual therapy with curative intent.