CYP2E1 Rsa I/Pst I polymorphism is associated with lung cancer risk among Asians

The genetic polymorphism of CYP2E1 Rsa I/Pst I is thought to have significant effect on lung cancer risk, but the results are inconsistent. In this meta-analysis, we assessed 21 published studies involving 9380 subjects of the association between CYP2E1 Rsa I/Pst I polymorphism and lung cancer risk. For the homozygote c2/c2 and c2 allele carriers (c1/c2+c2/c2), the pooled ORs for all studies were 0.734 (95% CI=0.628-0.847; P=0.035 for heterogeneity) and 0.852 (95% CI=0.777-0.933; P=0.004 for heterogeneity) when compared with the homozygous wild-type genotype (c1/c1). In the stratified analysis by ethnicity, the same significant risks were found among Asians for both the c2 allele carriers and homozygote c2/c2. Among mixed populations, only significant risk was associated with c2 allele carriers. No significant associations were found in all Caucasians genetic models. In the subgroup analyses by pathological types, for lung SC the ORs of the c2 allele carriers and the homozygote c2/c2 were 0.749 (95% CI=0.683-0.813; P=0.247 for heterogeneity) and 0.726 (95% CI=0.662-0.847; P=0.006 for heterogeneity), respectively. In the subgroup analyses by smoking status, there were no significant associations among smokers or non-smokers subgroup. This meta-analysis suggests that CYP2E1 Rsa I/Pst I c2 allele is a decreased risk factor for the developing lung cancer among Asians and lung SC.