Association of CYP1A1 and microsomal epoxide hydrolase polymorphisms with lung squamous cell carcinoma

Lung cancer is the leading cause of death among cancers in Taiwan. Although the etiology of lung cancer has yet to be defined, genetic variability in activities of metabolic enzymes has been correlated with lung cancer. In th e present study, the possibility of association of CYP1A1 and microsomal ep oxide hydrolase (HYL1) genetic polymorphisms with lung cancer was examined among 132 lung cancer patients and 259 controls in Taiwan. No significant a ssociation was observed for either CYP1A1 or HYL1 polymorphism alone and th e overall incidence of lung cancer after adjusting for age, gender and smok ing status. When cases were stratified according to histological type, ther e was significant association between CYP1A1*2A homozygote and squamous cel l carcinoma (SCC) (odds ratio (OR) 2.86; 95% confidence interval (CI) 1.33- 6.12). Similarly, the proportion of HYL1 genotypes corresponding to high or normal enzyme activities was higher in SCC than in controls (OR 1.96; 95% CI 1.04-3.70), A combination of susceptible CYP1A1 and HYL1 genotypes was f ound to be highly associated with lung cancer, especially with SCC (OR 6.76 ; 95% Cl 2.29-19.10). Our results suggest that the combination of CYP1A1 an d HYL1 polymorphisms is an important risk factor for lung SCC. (C) 2000 Can cer Research Campaign.