The landscape of intergenic-breakpoint fusion in lung cancer.

Abstract

e15002 Background: Kinase fusions have been proved as driver factors and drug targets for lung cancer. DNA-based next-generation sequencing (NGS) has been widely used for gene fusion detection in patients with lung cancer and intergenic-breakpoint fusions can be detected, in which breakpoints localize to intergenic regions. Theoretically, intergenic-breakpoint fusions are unlikely to be functional, but recent studies have found that intergenic-breakpoint fusions are potentially activated. However, the proportion of intergene-breakpoint fusion occurrence in lung cancer is still unclear. Hereby, next generation sequencing was performed to describe lung intergenic-breakpoint fusions for further research. Methods: Tumor tissue, pleural effusion, or blood samples of 6798 patients with lung cancer from Simceredx were collected for targeted NGS panel sequencing from June 2020 to January 2021. Gene rearrangements of ALK, ROS1, RET, NTRK(1-3) were assessed. Results: We found gene fusions in 4.43% (301/6798) patients with lung cancer totally, of which 59.1% (178/301) ALK fusions, 18.9% (57/301) RET fusions, 15.9% (48/301) ROS1 fusions and 6.64% (20/301) NTRK(1-3) fusions. The intergenic-breakpoint fusions accounted for all fusions of ALK, RET and ROS1 genes were 24.2% (43/178), 22.8% (13 /57) and 18.8% (9/48), respectively. In patients with NTRK intergenic fusions (50.0%, 10/20), NTRK1, NTRK2 and NTRK3 was involved in 2, 1, 7, respectively. Co-occurrence of different fusions was rare. Conclusions: Our data firstly revealed the specific intergenic-breakpoint fusions ( ALK, RET, ROS1, NTRK1-3) in lung cancer. The functional consequences identifying by RNA or protein assay and clinical validation need to be carried out in the future.