Abstract 5771: The refined stratification of receptor tyrosine kinase fusions in lung cancer

Abstract

Abstract Background: The overall survival of patients with the actionable receptor tyrosine kinase (TRK) fusions can be significantly prolonged after taking targeted kinase inhibitors. However, the outcomes are variable due to the different fusion types of the same driver gene. Method: Formalin fixed paraffin embedded tissues from patients with lung cancer between March 2018 and September 2021 were performed by using next generation sequencing (NGS) at Genetronhealth, a laboratory accredited by College of American Pathologists and Clinical Laboratory Improvement Amendments. Results: In a large cohort of 3768 patients with lung cancer, 348 cases harboring the actionable TKR fusions, including ALK, ROS1, RET, EGFR, MET, BRAF, NTRK1/2/3. TRK fusions can be divided into three types based on the breakpoints, partners and fusion models: single 3’ fusions, nonreciprocal fusions with the intact tyrosine kinase domain (TKD); single 5’ fusions, reciprocal fusions with the incomplete TKD; complex fusions, nonreciprocal/reciprocal fusions or nonreciprocal fusions with different partners. At the gene level, 58% (203 of 348) of TRK fusions were ALK, among which 71% of single 3’ ALK (144 of 203), 3% of single 5’ ALK (6 of 203) and 26% of complex fusions (53 of 203) were included. ROS1 fusions accounted for 14% (50 of 348) of all TRK fusions, and the proportions of single 3’ fusions, single 5’ fusions and complex fusions were 60% (30 of 50), 6% (3 of 50) and 34% (17 of 50), respectively. RET captured 19% (66 of 348) TRK fusions with 70% of single 3’ RET (46 of 66), 5% of single 5’ RET (3 of 66) and 26% of the complex fusions (17 of 66). EGFR owned 3% (9 of 348) with 33% of single 3’ EGFR (3 of 9), 33% of single 5’ EGFR (3 of 9) and 33% of the complex (3 of 9). MET, BRAF and NTRK1/2/3 shared the rest 5% of total fusions without complex type. Conclusion: Our research shows different types of TRK fusions in Chinese lung cancer patients, which can help guide the precise treatment in clinical. Citation Format: Chaoyang Liang, Lin Li, Xiaofang Liu, Qiuhua Liu, Baoming Wang, Chunyang Wang, Tonghui Ma, Fanlu Meng. The refined stratification of receptor tyrosine kinase fusions in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5771.