Abstract
PURPOSE: Despite advances in treatment, lung cancer remains the leading cause of cancer mortality. This study aimed to characterise genome-wide tumorigenesis events and to understand the hypothesis of the multistep carcinogenesis of lung adenocarcinoma (LUAD). MATERIALS AND METHODS: We conducted multiregion whole-exome sequencing of LUAD with synchronous atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ, or minimally invasive adenocarcinoma of 19 samples from three patients to characterize genome-wide tumorigenesis events and validate the hypothesis of the multistep carcinogenesis of LUAD. We identified potential pathogenic mutations preserved in preinvasive lesions and supplemented the finding by allelic variant level from RNA sequencing. RESULTS: Overall, independent mutational profiles were observed per patient and between patients. Some shared mutations including epidermal growth factor receptor (EGFR , p.L858R) were present across synchronous lesions. CONCLUSION: Here, we show that there are driver gene mutations in AAH, and they may exacerbate as a sequence in a histological continuum, supporting the Darwinian evolution model of cancer genome. The intertumoral and intratumoral heterogeneity of synchronous LUAD implies that multi-biomarker strategies might be necessary for appropriate treatment.