Acquired MET-DSTN Fusion Mediated Resistance to EGFR-TKIs in Lung Adenocarcinoma and Responded to Crizotinib Plus Gefitinib: A Case Report

•Mesenchymal-epithelial transition factor receptor (MET) is a potential therapeutic target in non-small cell lung cancer (NSCLC). However, MET gene fusions in NSCLC have rarely been found. •A novel gene fusion, MET-DSTN, and EGFR-L858R were detected by next-generation sequencing after the occurrence of resistance to osimertinib therapy. The patient obtained a dramatic clinical benefit upon treatment with crizotinib plus gefitinib, achieving a complete response one month later. •MET-DSTN fusion could be explored as one kind of mechanism of acquired resistance to EGFR-TKIs. Combined treatment with MET inhibitors and EGFR-TKIs is a potential therapeutic strategy. •Mesenchymal-epithelial transition factor receptor (MET) is a potential therapeutic target in non-small cell lung cancer (NSCLC). However, MET gene fusions in NSCLC have rarely been found. •A novel gene fusion, MET-DSTN, and EGFR-L858R were detected by next-generation sequencing after the occurrence of resistance to osimertinib therapy. The patient obtained a dramatic clinical benefit upon treatment with crizotinib plus gefitinib, achieving a complete response one month later. •MET-DSTN fusion could be explored as one kind of mechanism of acquired resistance to EGFR-TKIs. Combined treatment with MET inhibitors and EGFR-TKIs is a potential therapeutic strategy.