[Clinical perspective of precancerotic states in gastroenterology and their molecular genetics].

Gastrointestinal tract tumours represent an important cause of death in the Czech Republic. Diagnosis of the disease at its advanced stage with progression precluding radical surgical solution is a frequent common denominator. Detection of precancerous states, including congenital genetic defects or premalignant syndromes and malignant lesions may serve as a useful tool for early detection of disease risk or disease onset. Considering the incidence of individual types of tumours, this paper Focuses mainly on precancerotic states leading to malignant alterations of oesophagus, colorectum and pancreas. Apart from a concise morphological description of each premalignancy and its malignant transformation, a description of traditional molecular models of development and progression is also provided. Furthermore, we include a brief list of the most important genes contributing to the mechanism of malignant transformation in these three most important tumour diseases.