Effectiveness of crizotinib in a patient with mesenchymal-epithelial transition overexpression/fluorescence in situ hybridization-negative/next-generation sequencing-negative advanced lung adenocarcinoma: a case report

In recent years, the tyrosine kinase receptor mesenchymal-epithelial transition (MET) has become a target in non-small cell lung cancer (NSCLC). Crizotinib, a potent tyrosine kinase inhibitor (TKI) of anaplastic lymphoma kinase (ALK) and ROS1, has demonstrated its remarkable therapeutic effect in patients with MET amplified or MET exon 14 skipping mutated advanced-stage non-small-cell lung cancer in several previous reports (1-5). Methods to detect MET alteration includes immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), next-generation sequencing (NGS) and reverse transcription polymerase chain reaction (RT-PCR). Few cases reported response to crizotinib in advanced NSCLC patients according to the results of MET IHC staining. In this article, we report a case of crizotinib effectiveness in a pretreated patient with advanced lung adenocarcinoma detected as MET overexpression/FISH-negative/NGS-negative