SUMMARY. Imbalance between the phases of the biotransfotmation system (activation, detoxication and removal of toxic compounds) is one of the causes of multifactorial pathology developing. That is why study on the influence of the total contribution of polymorphic gene variants of xenobiotic biotransformation enzymes of all three phases on predisposition to lung cancer emergence is important. The aim of the work was to determine polymorphic variants of genes of xenobiotic biotransformation enzymes of lung cancer patients and to identify markers of predisposition to lung cancer. Association of homozygous GSTT1 gene deletion with predisposition to lung cancer was detected in residents of Belarus. Combinations of polymorphic gene loci of biotransformation enzymes exert a modifying effect on risk importance of GSTT1 genotype in lung cancer development. The combination 734AA CYP1A2/GSTT1(-)/GSTM1(+)/»slow« acetylator/3435CC MDR1 is of the highest risk importance. The combination »slow« acetylator/GSTT1(+)/GSTM1(+) exerts a protective effect.
Keywords: genetic polymorphism, xenobiotic biotransformation enzymes, lung cancer
