Molecular gene mutation profiles, TMB and the impact of prognosis in Caucasians and east Asian patients with lung adenocarcinoma.

Background: The difference in molecular gene mutation profile, tumor mutational burden (TMB) and their prognostic effects in lung adenocarcinoma between different ethnic groups are still unknown. A retrospective analysis was used to investigate the differences in lung adenocarcinoma driver gene mutations, TMB, and their impact on prognosis across different ethnic groups. Methods: The incidence of epidermal growth factor receptor (EGFR) mutations and follow-up data of 647 Chinese lung adenocarcinoma patients were compared with the data from 522 Caucasian patients in The Cancer Genome Atlas (TCGA) database. Moreover, a comprehensive analysis was performed to compare the differences in gene mutation frequency, signaling pathway variation, and TMB using the whole-exome sequencing (WES) data of Chinese patients with that of Caucasian patients. Results: A comparison of tumor signaling pathways and gene mutation profiles between Caucasians and Chinese revealed ethnic variations in the incidence of mutations in TGF-beta and RTK-RAS signaling pathways, with P values of 0.012 and 0.016, respectively. In the Caucasian population, the mutations in 5 signaling pathways and 18 genes were all significantly correlated with TMB, whereas in the Chinese population, only mutations in the Notch pathway and 6 genes were found to be associated with TMB-high. EGFR mutations showed a better prognosis in Chinese patients with lung adenocarcinoma, while the opposite was found in Caucasians patients. Conclusions: Variations in the incidence of mutations in signaling pathways involved in lung adenocarcinoma and the correlation of the signaling pathways with TMB may exist across different ethnic groups.