IL1B rs1143634 polymorphism, cigarette smoking, alcohol use, and lung cancer risk in a Japanese population.

BACKGROUND

Interleukin 1B (IL1B) is involved in pulmonary inflammation induced by environmental or occupational toxins. Chronic inflammation has been implicated in the development of lung cancer.

METHODS

We evaluated the role of IL1B (rs1143634, 3954C>T) in a case-control study comprised of 462 lung cancer cases and 379 controls in a Japanese population. Logistic regression was used to assess the adjusted odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS AND DISCUSSION

Individuals with a history of smoking and at least one T allele (adjusted OR = 5.45, 95% CI = 2.75-4.42, p < 0.01) presented a higher risk of lung cancer than those with the CC genotype (adjusted OR = 2.86, 95% CI = 2.02-4.05, p < 0.01) as compared with never smokers with the CC genotype (reference). The adjusted attributable proportion because of interaction between the IL1B rs1143634 genotypes and smoking was estimated to be 0.45 (95% CI = 0.08-0.83, p = 0.02), indicating that 45% of the excess risk for lung cancer in ever smokers with at least one T allele was due to additive interaction. Subjects with excessive alcohol intake and at least one T allele had a significantly higher risk (OR = 2.48, 95% CI =1.36-4.54, p < 0.01) than drinkers with appropriate intake and the CC genotype. There was no interaction between the polymorphism and alcohol intake.

CONCLUSIONS

Our findings indicate the possible association of the T allele carriers of the IL1B rs1143634 polymorphism with higher risk of lung cancer especially among smokers. Additional studies are warranted to confirm the IL1B rs1143634-smoking interaction suggested in this study.