Durable response to crizotinib in an advanced lung adenocarcinoma patient harboring rare CD47-MET fusion: a case report

Background: MET fusion is a rare type of structure rearrangement, reported only in 0.26% of non-small cell lung cancer (NSCLC). Some uncommon genomic variants, including MET fusions, have been detected with advanced detection technology. Therapeutic option for MET-rearranged NSCLC remains largely uncovered. Case Description: Herein, we described a 72-year-old male patient with a 10-year history of smoking who presented to our hospital with coughing, blood-tinged sputum, chest distress, and anhelation. He was diagnosed with stage IV lung adenocarcinoma harboring a CD47 (EX7)-MET (EX15) fusion, detected by next-generation sequencing (NGS). After one month of crizotinib treatment, the patient showed partial re-expansion of the collapsed right lower lobe, shrinkages of lymph node lesions, and reduced right pleural effusion. The patient achieved partial response (PR) to first-line treatment of crizotinib with a progression-free survival (PFS) of 8 months. Cabozantinib was subsequently administrated, and a short-term PR of fewer than three months was observed. The patient retained CD47-MET fusion and acquired MET D1228E at cabozantinib progression. Conclusions: This case provided the first clinical evidence for the efficacy of crizotinib in CD47-MET rearranged NSCLC and suggested MET D 122 8E as a resistance mechanism. NGS is a powerful tool for identifying rare MET gene variants in patients with NSCLC, which should be encouraged in clinical practice.