Inherited Rare, Deleterious Variants in ATM Increase Lung Adenocarcinoma Risk

Lung cancer is the leading cause of cancer deaths in the world, and lung adenocarcinoma (LUAD) is its most prevalent subtype. Symptoms are often found in advanced disease in which treatment options are limited. Identifying genetic risk factors will enable better identification of high-risk individuals.

To 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 data of 1083 patients with LUAD and 7650 controls, split into discovery and validation cohorts. Of these, we performed whole-exome sequencing on 97 patients and acquired the rest from multiple public databases. We annotated all rare variants for pathogenicity conservatively, using the guidelines of the American College of Medical Genetics and Genomics and ClinVar curation, and investigated gene-level RDV burden using penalized logistic regression. All statistical tests were two-sided.

We discovered and replicated the finding that the burden of germline ATM RDVs was significantly higher in patients with LUAD versus controls (combined cohort OR = 4.6; p = 1.7e-04; 95% confidence interval = 2.2-9.5; 1.21% of cases; 0.24% of controls). Germline ATM RDVs were also enriched in an independent clinical cohort of 1594 patients from the MSK-IMPACT study (0.63%). In addition, 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 (combined AJ cohort OR = 2.7, p = 6.9e-03, 95% confidence interval = 1.3-5.3).

Our results indicate that ATM is a moderate-penetrance LUAD risk gene and that LUAD may be a part of the ATM-related cancer syndrome spectrum. Individuals with ATM RDVs are at an elevated LUAD risk and can benefit from increased surveillance (particularly computed tomography scanning), early detection, and chemoprevention programs, improving prognosis.