Background: Mesenchymal–epithelial transition (MET ) exon14 skipping mutations represent a clinically unique molecular subtype of NSCLC. The prevalence rates of MET  exon 14 skipping in lung adenocarcinoma (ADC) range from 0.9% to 4.0% in Asian populations. Since some somatic variants that do not encompass the MET  exon 14 splice sites might also induce MET  exon 14 skipping, the RNA-based sequencing is speculated as the most accurate method for detecting exon 14 skipping.
Patients and Methods: A total of 951 histochemistry (IHC) was performed in 405 samples simultaneously.
Results: The overall estimated prevalence of MET  exon 1NSCLC patients from two hospitals were enrolled in this study. MET  exon14 skipping was detected using RNA-based next-generation sequencing (NGS). Also, immuno4 skipping was approximately 1.8% in ADCs and 1.7% in NSCLCs. The detection rate of MET  exon 14 skipping from surgical resection specimen was 2.3% in NSCLCs and 2.0% in ADCs. The MET  exon 14 skipping was identified in 6.6% of EGFR /KRAS /ALK /ROS1 /RET -negative ADCs. Additionally, PD-L1 was found to be highly expressed in NSCLC patients harboring MET  exon 14 skipping (P < 0.01).
Conclusion: The prevalence of MET  exon14 skipping in lung ADCs in the East Asian population was similar to that of the Western population as assessed by RNA-based NGS. The NSCLC patients with MET  exon 14 skipping were older than those with other oncogenic driver mutations, such as EGFR, ALK , and ROS1 . In addition, PD-L1 was highly expressed in NSCLC patients with MET  exon 14 skipping.
Keywords: non-small cell lung cancer, MET  exon14 skipping, next-generation sequencing, PD-L1