Globally, lung cancer is the most common type of cancer. 1 The incidence of lung cancer ranges between 27.8 and 47.4 per 100 000 in men and between 11.1 and 18.6 per 100 000 in women. 2 Its etiology includes cigarette smoking, occupational exposures to asbestos and nickel, genetic predisposition and various lung diseases. 3 Several studies have demonstrated that the genetic basis of lung cancer involves mutations in the tumor suppressor genes p53 and Rb, D12S0134, D6S474 and D19S246 microsatellite markers, checkpoint kinase 2 gene mutations in the epidermal growth factor receptor, glutathione-S-transferase (GST) P1, myeloperoxidase (MPO), cytochrome P450 (CYP)1A1, cyclooxygenase 8473T > C and TGF-beta1 −509C > T and 869T > C polymorphisms, endothelial nitric oxide (NO) synthase gene intron 4, 27 bp repeat polymorphism. 4-6