Objective: To investigate the association and interaction between smoking and the nicotine acetylcholine receptor subunits alpha 5(CHRNA5) gene polymorphisms on lung cancer in Chinese men.
Methods: A case-control study was employed with a total of 204 male lung cancer patients and 821 healthy control subjects enrolled in the study. All the subjects were interviewed under a structured questionnaire with the contents on socio-demographic status and smoking behavior. Venous blood samples were collected to measure single nucleotide polymorphism of rs17486278 in CHRNA5. A series of multivariate logistic regression models were performed to assess the association and interaction between smoking and the CHRNA5 gene polymorphisms on lung cancer.
Results: After controlling for potential confounding factors, data from the multivariate logistic regression analysis showed that individuals with smoking >15 cigarettes per day would significantly increase the risk of lung cancer when compared to the non-smokers (OR = 3.49, 95%CI:2.29-5.32). However, no associations between CHRNA5 rs17486278 polymorphisms and lung cancer were found. Furthermore, those who smoked 1-15 cigarettes per day had a positive interactive effect between rs17486278 CC genotype and lung cancer (OR = 16.13, 95% CI:1.27-205.33). Results from further stratified analysis on smoking behaviors and rs17486278 genotypes indicated that when compared with non-smokers on rs17486278 AA genotype, those individuals who smoked 1-15 cigarettes per day with rs17486278 CC genotype, individuals smoking >15 cigarettes per day with AA genotype and individuals smoking >15 cigarettes per day with AC genotype, all had a higher risk of developing lung cancer, with their OR value as 8.14(95% CI:1.17-56.56), 3.84 (95% CI:1.30-11.40) and 5.32 (95% CI:1.78-15.93), respectively.
Conclusion: There was an interaction between smoking and CHRNA5 gene polymorphism on lung cancer.