Association between environmental tobacco smoke exposure and lung cancer susceptibility: Modification by antioxidant enzymes genetic polymorphisms

AbstractBackgroundEnvironmental tobacco smoke (ETS) is the primary etiological factor of lung cancer. However, only 10–15% of smokers develop lung cancer, suggesting genetic role in modifying individual susceptibility to lung cancer. Antioxidant enzyme functional genetic polymorphisms should be considered.Aim of the workThe present study aimed to evaluate the role of antioxidant enzyme activity and genetic polymorphisms in modifying the susceptibility to lung cancer among individuals exposed to ETS.Subjects and methodsA total of 150 male subjects were divided into three groups: 50 lung cancer patients, 50 chronic smokers and 50 passive smokers. Genotyping of mEH exon 3 (Tyr113Hist) and exon 4 (Hist139Arg) polymorphisms was done by PCR–RFLP technique. MnSOD (Val16Ala) polymorphism was detected by Real time-TaqMan assay. Erythrocyte MnSOD activity was measured spectrophotometrically.ResultsETS exposed individuals (both active and passive smokers) who carried His allele of mEH exon3 have 2.9-folds increased risk of lung cancer (OR 2.9 P