Inherited rare, deleterious variants in ATM increase lung adenocarcinoma risk

IntroductionLung cancer is the leading cause of cancer deaths in the world, and adenocarcinoma (LUAD) is its most prevalent subtype. Symptoms often appear in advanced disease when treatment options are limited. Identifying genetic risk factors will enable better identification of high-risk individuals. MethodsTo identify LUAD risk genes, we performed a case-control association study for gene-level burden of rare, deleterious variants (RDVs) in germline whole-exome sequencing (WES) data of 1,083 LUAD patients and 7,650 controls, split into discovery and validation cohorts. Of these, we performed WES on 97 patients and acquired the rest from multiple public databases. We annotated all rare variants for pathogenicity conservatively, using ACMG guidelines and ClinVar curation, and investigated gene-level RDV burden using penalized logistic regression. All statistical tests were two-sided. ResultsWe discovered and replicated the finding that the burden of germline ATM RDVs was significantly higher in LUAD patients versus controls (ORcombined=4.6; p=1.7e-04; 95% CI=2.2-9.5; 1.21% of cases; 0.24% of controls). Germline ATM RDVs were also enriched in an independent clinical cohort of 1,594 patients from the MSK-IMPACT study (0.63%). Additionally, we observed that an Ashkenazi Jewish (AJ) founder ATM variant, rs56009889, was statistically significantly more frequent in AJ cases versus AJ controls in our cohort (ORcombined, AJ=2.7, p=6.9e-03, 95% CI=1.3-5.3). ConclusionsOur results indicate that ATM is a moderate-penetrance LUAD risk gene, and that LUAD may be part of the ATM-related cancer syndrome spectrum. Individuals with ATM RDVs are at elevated LUAD risk and can benefit from increased surveillance (particularly CT scanning), early detection and chemoprevention programs, improving prognosis.