Abstract
BACKGROUND: Epidermal growth factor receptor (EGFR) mutations were frequently found with concomitant genetic alterations in lung adenocarcinoma (LUAD). This study aimed to investigate the profile of concomitant alterations of EGFR-mutant LUAD ≤3 cm in size and its prognostic effect on recurrence. METHODS: From January 2018 to December 2018, patients with resected LUAD ≤3 cm in size in Shanghai Chest Hospital were identified. All patients underwent capture-based targeted next-generation sequencing (NGS) with a panel of 68 lung cancer-related genes and were found with EGFR mutation. Clinicopathological and molecular characteristics and recurrence-free survival (RFS) were analyzed. RESULTS: A total of 637 patients were enrolled in this study. The top three frequent co-mutational genes were TP53 (179 of 637, 28.1%), PIK3CA (27 of 637, 4.2%), and ATM (22 of 637, 3.5%). The most common amplified genes were EGFR (37 of 637, 5.8%), followed by CDK4 (37 of 637, 5.8%) and MYC (12 of 637, 2.0%). Only TP53 mutation and EGFR amplification were adverse prognostic factors for RFS (all p < 0.001) in univariate analysis. Multivariable analysis further demonstrated that TP53 mutation and EGFR amplification were independent risk factors for RFS [(hazard ratio (HR) 2.07, 95% confidence interval (CI) 1.07-4.00, p = 0.030; HR 3.09, 95% CI 1.49-6.40, p = 0.002, respectively]. CONCLUSIONS: Concomitant TP53 mutation and EGFR amplification were poor prognostic factors for RFS in patients with EGFR-mutant resected LUAD. Our findings provide valuable understanding of the impact of concurrent alterations and implication for better implementation of precision therapy for patients.