Characteristics of gene mutations in Chinese single-center pulmonary adenocarcinoma patients and comparison with European and American pulmonary adenocarcinoma populations

Objective To explore the characteristics and significances of gene mutations in pulmonary adenocarcinoma, and to provide evidence for targeted medication. Methods High throughput sequencing based target-capture sequencing was performed in 104 patients with pulmonary adenocarcinoma to detect the mutational status of 56 cancer-related genes. All patients were diagnosed in the First People's Hospital of Kunshan from May 2017 to August 2018. The mutational characteristics of pulmonary adenocarcinoma was analyzed and compared with European and American pulmonary adenocarcinoma populations. The correlations between mutational characteristics and clinical features were analyzed, and the mutation sites for targeted medication were screened. Results Among 104 patients with pulmonary adenocarcinoma, totally 34 mutational genes were detected in 84 patients (81%, 84/104). Highly frequent mutations included epidermal growth factor receptor (EGFR) (49%, 51/104), TP53 (21%, 22/104), KRAS (13%, 14/104), and BRAF (6%, 6/104). Among all the 187 variants, 76% (142/187) were non-synonymous missense mutations, 13% (24/187) were small fragment deletions, 6% (12/187) were copy number variants, 3% (5/187) were small fragment insertions, and 2% (4/187) were nonsense site mutations. Among 104 patients with pulmonary adenocarcinoma, 34 targeted drug-associated mutations of 13 genes were detected in 68 patients (65%), and 19 (18%) patients harbored ≥ 2 targeted drug-associated mutations. EGFR mutations were more common in female patients than in male patients [62% (34/55)vs. 35% (17/49), χ2= 7.629, P= 0.006], while KRAS mutations were more frequent in male patients than in female patients [22% (11/49) vs. 5% (3/55), χ2= 6.424, P= 0.011]. The mutation frequencies of gene EGFR, TP53, KRAS, and CDKN2A in Chinese single-center (the First People's Hospital of Kunshan) and European and American adenocarcinoma populations were significantly different (all P < 0.05). Conclusions The molecular mutational characteristics of pulmonary adenocarcinoma are complex, and vary greatly among different populations. High throughput sequencing-based multiple-gene detection can reveal its mutational features comprehensively, and that has important roles in personal targeted medication guidance, drug-resistance monitoring and prognosis evaluation. Key words: Lung neoplasms; Adenocarcinoma; High-throughput nucleotide sequencing; Mutation; Molecular targeted therapy