Abstract 3009: Measured and genetically-predicted leukocyte telomere length and lung cancer risk in the prospective UK Biobank
Authors: Wong Jason Yat-Yang , Blechter Batel , Hubbard Aubrey K. , Shi Jianxin , Hu Wei , Rahman Mohammad , Gadalla Shahinaz , Machiela Mitchell , Rothman Nathaniel , Lan Qing 
Published: April 2023

Abstract
Telomere length is a biomarker reflective of aging and genomic instability. We previously found associations between longer measured leukocyte telomere length (LTL) and increased lung cancer risk in a pooled nested case-control study with 847 cases. Additionally, we reported that longer genetically-predicted telomere length (gTL) using a polygenic risk score (PRS) with 7 single nucleotide polymorphisms (SNPs) was associated with increased lung cancer risk among never-smoking Asian women. To investigate further, we conducted prospective cohort analyses of pre-diagnostic LTL and gTL in relation to risk of overall lung cancer and its subtypes in the UK Biobank. With over triple the number of cases, we had expanded statistical power to investigate lung cancer, adenocarcinoma (LUAD), and squamous cell carcinoma (SCC) among subgroups defined by smoking status and sex in this predominantly European study population.
We analyzed 371,890 participants at baseline. Over the 12.36±1.64SD year follow-up, 2829 incident lung cancer cases were diagnosed, including 1078 LUAD and 487 SCC. LTL was measured using qPCR. Using European data, we calculated a weighted PRS for gTL. The PRS was derived from 130 linkage disequilibrium pruned SNPs (r2 &gt; 0.01) associated with longer LTL in the UK Biobank. Multivariable Cox regression was used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) of lung cancer in relation to log-transformed continuous and quartiles (Q) of LTL and gTL separately. Associations were estimated in the overall analytic sample and among smoking-sex subgroups. We conducted Mendelian Randomization (MR) analyses using MR-PRESSO with 130 genetic instruments to assess causal associations between LTL and lung cancer among Europeans.We found a strong dose-response relationship between longer LTL and increased lung cancer risk (p-trend= 2.6E-05), with the highest quartile being statistically significant (HRQ4vs.Q1=1.27, 95%CI: 1.15-1.42). The association was apparent for LUAD (p-trend=6.6E-10; HRQ4vs.Q1=1.78, 95%CI: 1.50-2.12), but not SCC. The lung cancer associations were prominent among never-smoking women (p-trend=4.0E-05) and never-smoking men (p-trend=2.0E-03). We also found dose-response relationships between longer gTL and risk of lung cancer (p-trend=4.2E-06) and LUAD (p-trend=2.1E-08). Additionally, we found evidence for causal associations between longer LTL and risk of lung cancer (HRper 1 SD gTL=1.87, 95%CI: 1.49-2.36, p=4.0E-07) and LUAD (HRper 1 SD gTL=2.45, 95%CI: 1.69-3.57, p=6.5E-06). Longer leukocyte telomere length potentially reflects biological processes relevant to the pathogenesis of lung cancer, particularly LUAD.
Citation Format: Jason Yat-Yang Wong, Batel Blechter, Aubrey K. Hubbard, Jianxin Shi, Wei Hu, Mohammad Rahman, Shahinaz Gadalla, Mitchell Machiela, Nathaniel Rothman, Qing Lan. Measured and genetically-predicted leukocyte telomere length and lung cancer risk in the prospective UK Biobank [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3009.