LAUSR

Abstract Background MET amplification is a rare genetic mutation which can be treated with small-molecule inhibitor-crizotinib. Based on the detection of next-generation sequencing, the molecular characteristics and the efficacy of crizotinib among different subsets of MET amplification in lung cancer patients is poorly understood. Methods From January 2018 to April 2019, patients with MET amplification detected by next-generation sequencing were retrospectively collected and the efficacy of crizotinib among different subsets of patients were analyzed. Results In our study, 4.16% (112/2694) patients were found to have MET amplification and only 19 patients treated with monotherapy crizotinib. Among the 112 MET amplification patients, primary (with or without other mutation) MET amplification accounted for 3.27% (82/2507) and 16.04% (30/187) re-biopsy patients were found to have acquired MET amplification after the failed treatment of EGFR-TKI. The frequency of MET amplification combined with EGFR 21L858R was slightly higher than that of MET amplification combined with EGFR 19 del (primary or acquired). Primary MET amplification can occur simultaneously with EGFR 20ins or ALK rearrangement. In survival analysis, the median PFS of 10 patients with copy number greater than 4 (CN > 4) seems longer than the nine patients with copy number less than or equal to 4 (CN ≤ 4) (4.7 months vs 2.7 months) and the two curves were separate, but failed to get a statistical significance (p = 0.085). No significant difference has been discovered between the median PFS of primary (4.04 months; 95%CI: 0.33-7.74 months) and acquired (2.99 months; 95% CI: 2.51-3.47 months; P = 0.382) MET amplification. Conclusions 4.16% lung cancer patients were found to have MET amplification based on the detection of NGS. MET amplification patients treated with crizotinib with copy number greater than 4 (CN > 4) seem have longer PFS. No obvious survival difference has been discovered between primary and acquired MET amplification. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.