Smoking affected the association between IL1B gene polymorphisms and the risks of NSCLC

Abstract

Objective The purpose of this study was to explore the association among IL1B polymorphisms, smoking and the risks of non-small cell lung cancer. Methods IL1B polymorphisms (rs1143623G>A, rs12621220G>C) were genotyped in 889 non-small cell lung cancer (NSCLC) cases and 1005 healthy controls. Results The results showed that smoking affected NSCLC susceptibility: People with smoking history have much higher risk of NSCLC than people without smoking history (after adjustment for factors, such as gender, age, pack-year, OR=3.744, 95% CI=2.885~4.858; P=2.980×10-23); Furthermore, people with higher smoking pack-years have much higher risk of NSCLC than those with lower smoking pack-years (P=4.350×10-29), and the persistent smokers who smoked lower pack-years, has significant protective effect on NSCLC susceptibility (aOR=0.219, 95% CI=0.164~0.291; P=2.233×10-25) than the people quitted smoking but smoked more pack-years (P=0.016). In addition, we found that the associations between NSCLC susceptibility and IL1B polymorphisms was influenced by smoking status. The logistic regression analysis results showed that: For rs1143623, compared with the GG genotype, GC was significantly associated with decreased risk of NSCLC for the people of smoking cessation (aOR = 0.543, 95% CI=0.291~1.011; P=0.054), and this protection was relatively stable when combined with CC genotype (aOR=0.563, 95% CI=0.313~1.013; P=0.055). In subgroups analysis we found that this protective effect was mainly existed in the subgroup of adenocarcinoma (ADC) (OR=0.491, 95% CI=0.241~1.001; P=0.050). For rs12621220, compared with the GG genotype, GA was significantly associated with decreased risk of NSCLC for the people of smoking cessation (OR=0.427, 95% CI=0.210~0.868; P=0.019), and this protective effect was mainly related to the ADC, combined with AA genotype, the protective effect did not disappear (OR=0.479, 95% CI=0.248~0.925; P=0.029). Conclusion Smoking status modified the associations between IL1B polymorphisms and NSCLC susceptibility. Key words: IL1B; SNP; Smoking; NSCLC