[Biological aspects and perspectives applicable to the chemoprevention of cancer of the upper respiratory-digestive tract]. / Aspetti biologici e prospettive applicative della chemioprevenzione nel cancro delle vie aero-digestive superiori.

After defining chemoprevention a description is given of the phases of differentiation in normal epithelial cells and the features of proliferation in neoplasias developing in this epithelium. The latest studies on carcinogenesis indicate various types of prevention with which one can alter this transformation process. Epidemiological studies have shown that subjects with low serum levels of Vit-A or Beta carotenoids are at high risk of developing epithelial cancer. Three main categories of agents inducing cell transformation are described: a) physiological induction agents; b) non physiological induction agents; c) cytotoxic drugs. In regard to clinical use, some studies have focussed on the importance of Vit-A in chemoprevention of risk conditions (pre-cancerous lesions) and in prevention of cancer recurrence. The authors point out the increasing interest in the use of retinoids in the chemoprevention of head and neck cancer and report some personal clinical experience.