Response to Crizotinib Observed in Lung Adenocarcinoma with MET Copy Number Gain but without a High-Level MET/CEP7 Ratio, MET Overexpression, or Exon 14 Splicing Mutations

MMNG HOS Transforming gene (MET) is an important driver gene in non-small cell lung cancer. Yet, MET-relevant biomarkers predictive of clinical response to MET inhibitors remain elusive. Limited studies have indicated some possibly effective biomarkers, including amplification with a high-level MET/centromere probe of chromosome 7 (CEP7) ratio, MET exon 14 (METex14) splicing mutations, and MET over expression. MET copy number gain (MCNG) is an independent negative prognostic factor in non-small cell lung cancer. Therefore, there remains a lack of clinical evidence regarding whether MCNG is a biomarker predictive of response to MET inhibitors. Here we report a patient with lung adenocarcinoma with MCNG but without a high-level MET/CEP7 ratio or METex14 splicing mutations who achieved a rapid response to crizotinib, indicating that MCNG may be an independent predictive biomarker for response to MET inhibitors. (C) 2015 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.