Lung cancer is the most frequent cancer among men in many countries. It is the result of interactions between genetic and environmental factors, among which tobacco smoking is a key environmental factor. CHRNA5, Cholinergic Receptor, Neuronal Nicotinic, Alpha Polypeptide-5, was previously reported to be associated with lung cancer risk. To identify the genetic susceptibility and tobacco smoking that influence lung cancer risk in Han population, we performed a case-control study in 228 patients and 301 controls. These data were compared using the χ(2)-test, genetic model analysis, and haplotype analysis. rs495956, rs680244, rs601079, rs555018, 588765 and rs11637635 showed an increased risk of lung cancer in both allelic model and genetic mode analysis. The genotype G/A-A/A of rs11637635 was most strongly associated with a 2.17-fold increased risk of lung cancer in dominant model (p = 0.018). One SNP, rs684513, was associated with a 0.645-fold decreased risk (p = 0.033) in allelic model analysis. By haplotype association analysis, haplotype sequences CTTATCAAAGA and GA of CHRNA5 were found to be associated with a 2.03-fold and 1.91-fold increased lung cancer risk (p < 0.05). Our results, combined with those from previous studies, suggest that genetic variation in CHRNA5 may influence susceptibility to lung cancer among Han smokers.
Keywords: CHRNA5; Lung cancer; SNP; case-control studies; smoking behavior.