Abstract 6149: Polygenic risk score and lung adenocarcinoma risk among never-smokers by EGFR mutation status

Abstract Background: Lung cancer is the leading cause of cancer mortality worldwide, and incidence rates for the disease in never-smokers is among the highest in East Asian (EAS) women. Epidermal growth factor receptor (EGFR) is a transmembrane protein that regulates cellular proliferation and apoptosis, and mutations in the EGFR gene have been found to be a defining hallmark of lung adenocarcinoma (LUAD). We investigated if overall genetic susceptibility to LUAD, defined as a polygenic risk score (PRS), is differentially associated with LUAD by EGFR mutation status. Methods: The study consists of 998 female never-smoking histologically confirmed LUAD cases with data on EGFR mutation status and 4,544 female never-smoking controls from the Female Lung Cancer Consortium in Asia. Germline DNA samples were genotyped using the 370K, 610Q, or 660W microarrays. Genomic DNA extracted from fresh, frozen or formalin-fixed paraffin-embedded tumor tissue samples of LUAD cases were genotyped for EGFR mutations on exons 19 and 21. We defined cases with EGFR mutation on either exon as EGFR+ (n=518) and cases without such EGFR mutation as EGFR- (n=480). Weights from 942,592 single nucleotide variants derived from a previously conducted genome-wide association study were used in a Bayesian-based approach, LDpred2, to derive a PRS for all participants. We estimated the odds ratios (OR) and 95% confidence intervals (CI) for the association between continuous PRS, PRS quartiles and tumor EGFR mutation status using logistic regression models in a case-case analysis, as well as using a multinomial logistic regression treating controls as the reference. All models were adjusted for age, study and the top 10 principal components. Results: In case-case comparisons, compared to EGFR- LUAD, we found a positive association between continuous PRS and risk of EGFR+ LUAD (OR=1.17, 95% CI: 1.02, 1.34), as well as a dose-response relationship between quartiles of the PRS and EGFR+ LUAD (p-trend=0.003). We further found that the association between the fourth quartile of the PRS with EGFR+ LUAD (OR=8.63, 95% CI: 5.67, 13.14) was significantly higher than the association between the fourth quartile of the PRS with EGFR- LUAD (OR=3.50, 95% CI: 2.44, 5.00) compared to controls (p-heterogeneity=0.004). Conclusions: We found that the PRS developed for LUAD in EAS individuals was more strongly associated with EGFR+ LUAD compared to EGFR- LUAD, suggesting that germline genetic susceptibility may be differentially associated with LUAD in never-smoking female EAS patients depending on the cancer’s mutation status. Given that patients with LUAD respond differently to treatments that are used as targeted therapy depending on their EGFR mutation status, our findings may have important public health and clinical implications, which may guide risk stratification, screening, and treatment. Citation Format: Batel Blechter, Chao Agnes Hsiung, Keitaro Matsuo, Kouya Shiraishi, Kevin Wang, Haoyu Zhang, Wei Jie Seow, Jianxin Shi, Nilanjan Chatterjee, Jason Y.Y. Wong, Juncheng Dai, H. Dean Hosgood, I-Shou Chang, Jiyeon Choi, Wei Hu, Wei Zheng, Young Tae Kim, Xiao-Ou Shu, Qiuyin Cai, Pan-Chyr Yang, Dongxin Lin, Kexin Chen, Yi-Long Wu, Hongbin Shen, Takashi Kohno, Stephen J. Chanock, Nathaniel Rothman, Qing Lan. Polygenic risk score and lung adenocarcinoma risk among never-smokers by EGFR mutation status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6149.