[Chemoprevention of cancer]

Chemoprevention, as one of the newest components of the fight against cancer, deals with various chemical compounds which can prevent the occurrence of malignant tumours. New experimental results achieved during the recent decades in the field of understanding of the process of carcinogenesis, have enabled a more rational approach to the prevention of normal cell malignization. It has been shown, that a number of investigated compounds are able to interact selectively with the particular phase (initiation, promotion, progression) of the multistep process of carcinogenesis. Activity of chemopreventive compounds can be evaluated by systematic analysis of various biomarkers in patients who are in high risk. The biomarkers include genetic markers (mutations, gene amplification), cellular markers (rate of proliferation), histologic markers (leukoplakia, metaplasia), or biochemical markers (blood level of various enzymes, or tumour antigens). The number of extensive clinical trials has recently increased and some positive results have been reported in the testing of various compounds preventing the appearance of some malignant tumours (breast, colon, prostate, etc.). The search for new, effective chemopreventive compounds might provide a valuable new tool aimed at the decrease in both cancer morbidity and mortality. (Ref. 37.)