Influence of smoking and the polymorphisms of CYP1A1 and GSTM1 on the susceptibility of lung cancer

Objective To study the relationship of cytochrome P-450 1A1(CYP1A1) and glutathione S-transferase M1 (GSTM1) polymorphisms with occurrence of lung cancer.Methods PCR-RFLP was used to determine genetic polymorphisms of CYP1A1 and GSTM1 in 103 patients with lung cancer and 138 healthy controls.Logistic regression analysis was used to assess the value of odds ratio (OR) and confidential intervals (CI) between different genotypes and smoking after adjusted by ages and gender.Results The allele frequencies of CYP1A1 M1 were 27.6% and 42.7% in control and lung cancer groups,respectively.The allele frequencies of GSTM1 deletion were 44.2% and 61.2% in control and lung cancer groups,respectively.OR for the CYP1A1 (B) or (C) genotype indicated 3.19 and 2.61-fold increased risk for developing lung cancer.The adjusted OR of the GSTM1 deletion genotype showed a 2.09-fold increased risk for lung cancer.Both associations were statistically significant.The increased risk for developing lung cancer was 5.72 folds for the individuals with combination of the CYP1A1(B or C) and GSTM1 deletion genotypes.CYP1A1 M1 and the GSTM1 deletion genotypes increased risk for developing small cell carcinoma and squamous carcinoma,significantly.Conclusion The mutant genotypes of the CYP1A1 M1 and GSTM1 deletion polymorphisms are the risk for lung cancer.CYP1A1 M1 and GSTM1 interact obviously,both of which have the joint effect with smoking.