Classification and clinical consequences of precancerous lesions in the digestive and respiratory tracts.

The adequate appraisal of precancerous changes is of the utmost importance in our everlasting fight against cancer, and its socio-medical relevance is acknowledged world-wide. In every country where epidemiologists register a rising incidence of malignant neoplasms, endeavours must focus not only on the early diagnosis of existing cancer, but even more on detecting the signs of coming tumors. That is why today the precancerous lesions are a main point of interest in cancer research all over the world for pathologists, radiologists, surgeons, obstetricians, etc.