Objective: To investigate the association of TNF-β 252A >G variant with the risk of non-small cell lung cancer (NSCLC).
Methods: Total 956 patients with NSCLC were recruited between January 2000 and December 2008 at Cancer Hospital, Chinese Academy of Medical Science as the case group, and 994 frequency-matched controls were randomly selected from a pool of cancer-free subjects recruited from a nutritional group. All the participants were unrelated Han Chinese. There were no age, gender restrictions. Smoking status of the subjects was surveyed. Informed consent was obtained and 3 ml peripheral blood was collected from each subject. All samples were genotyped by polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). The OR and 95%CI were estimated by logistic regression to evaluate the relationship between TNF-β 252 A/G variant and the risk of lung cancer.
Results: The frequencies of TNF-β 252 AA, AG and GG genotype were 30.9% (307/994) , 47.4% (471/994) and 21.7% (216/994) in lung cancer cases and 35.7% (341/956) , 48.1% (460/956) and 16.2% (155/956) in controls. Logistic regression analysis revealed that TNF-β 252 GG genotype contributed to a decreased risk of developing NSCLC (OR = 0.64, 95%CI: 0.49-0.83) compared with AA genotype. When stratified by smoking status, the individuals with 252 GG genotype had a significant increased risk of NSCLC (OR = 1.54, 95%CI:1.00-2.39) among smokers; which was less than those with AA genotype among smokers (OR = 2.88, 95%CI:1.91-2.24). When further stratified by smoking index, individuals with 252 GG genotype had a significant decreased risk of NSCLC among heavy smokers with OR (95%CI) of 2.24 (1.33-3.74), which was less than those with AA genotype (OR = 4.62, 95%CI:2.88-7.41).
Conclusion: TNF-β genetic variant may interact with environment factor to contribute to the susceptibility to NSCLC.