Abstract 1345: Evidence for genetic mediation of lung cancer through hay fever.

Abstract Introduction: In the past decade, advances in genetics have led to the discovery of numerous lung cancer susceptibility variants. The majority of these variants have been found to influence lung cancer susceptibility via tobacco exposure or nicotine addiction; however, recently, researchers have observed lung cancer susceptibility variants that mediate through Chronic Obstructive Pulmonary Disease (COPD). Studies involving potential genetic factors related to other lung-related conditions, such as pneumonia and/or hay fever have been limited. The genetic variants related to underlying mechanism of hay fever on the development of lung cancer are interesting to pursue as hay fever has been showed to be protective against lung cancer. Methods: Cases included 1154 histological-confirmed Caucasian lung cases from MD Anderson Cancer Center in Houston, Texas, and controls included 1137 individuals recruited through the Kelsey-Seybold Clinics in Houston, Texas. These cases and controls were a subset of participants from a lung cancer case-control study conducted that has available Genome-wide association study (GWAS) data (317,498 SNPs). We first conducted an association analysis in PLINK to determine the association of each SNP with both lung cancer and hay fever and find SNPs that showed a joint significance for both hay fever and lung cancer in opposite directions (p-value < 0.05 for both). We then performed mediation analyses with the SNPs that showed significance for both hay fever and lung cancer. Finally, we inferred SNPs in regions that contained a collection of tag SNPs that mediate lung cancer risk through hay fever. Results: Two hundred and forty six SNPs were found to be statistically significant (p-value < 0.05) for both hay fever (protection) and lung cancer (risk), and 76 of these SNPs maintained their significance level after mediation analysis. SNP rs7159751 on chromosome 14 had the highest mediation effect of 19.83%. A collection of SNPs on the Neuregulin 3 gene (NRG3) that mediate lung cancer risk through hay fever was found on Chromosome 10 which has been shown to activate the JAK-STAT signal transduction pathway and stimulate lung epithelial cell proliferation. Conclusion: This is the first study to have investigated the mediation effects of hay fever on lung cancer risk. Our data supports the mediation role of certain SNPs in lung cancer through hay fever and points to specific transduction pathway. Future studies are needed to validate these results in external populations. Citation Format: Anthony D'Amelio, Chi H. Nguyen, Randa El-Zein, Margaret R. Spitz, Xifeng Wu, Carol J. Etzel. Evidence for genetic mediation of lung cancer through hay fever. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1345. doi:10.1158/1538-7445.AM2013-1345