Genetic polymorphisms of tobacco- and alcohol-related metabolizing enzymes and oral cavity cancer.

Both genetic and environmental factors are involved in the development of cancer. Oral cavity cancer has been reported to be epidemiologically associated with tobacco and alcohol consumption. We examined genetic polymorphisms of the glutathione-S-transferase (GST) M1/T1, cytochrome P-450 (CYP) 1A1/2E1 and aldehyde dehydrogenase 2 (ALDH2) genes in 92 Japanese patients with oral cavity cancer and 147 unrelated non-cancer Japanese controls. There was a significant association between cigarette smoking and cancer risk but no significant association between alcohol consumption and cancer risk. The frequency of the GSTM1 null genotype was significantly higher in cancers (58.7%) compared with controls (46. 3%). However, there were no significant differences between controls and patients with oral cavity cancer in the polymorphisms of the GSTT1, CYP1A1, CYP2E1 and ALDH2 genes. From statistical evaluation on various combinations of genotypes, we did not observe any gene combinations associated with cancer risk. There were also no genetic polymorphisms associated with increased risk of oral cavity cancer among smokers and drinkers. These results imply that the GSTM1 null genotype has a weak correlation, but another 4 genetic polymorphisms are unlikely to be associated, with oral cavity cancer among Japanese. Copyright 1999 Wiley-Liss, Inc.