De Novo MET-amplified NSCLC treated with savolitinib achieved remarkable tumor regression: a case report and review of literature

Primary MET amplification is an infrequent tumorigenic driver gene alteration identified in pulmonary neoplasms. Data on the effectiveness of MET-tyrosine kinase inhibitor (TKI) therapy in de novo MET amplification are relatively scarce, and there remains a dearth of empirical evidence supporting the use of precision therapy as first-line treatment for advanced non-small cell lung cancer (NSCLC) with primary MET amplification. We present a case of advanced lung adenocarcinoma in an elderly patient with primary MET amplification. The patient had an initial ECOG Performance Status (PS) 2. DNA-NGS analysis of tissue samples revealed a MET gene copy number (GCN) of 8, indicating MET amplification, without other oncogenic mutations associated with available drugs being detected. This finding was validated by MET fluorescence in situ hybridization (FISH), which showed cluster amplification. Initial treatment with savolitinib resulted in a sustained partial response lasting more than sixteen months. Our results suggest that savolitinib is effective and safe for the treatment of elderly patients with de novo amplified MET metastatic NSCLC and may therefore be considered a potential treatment option worthy of prospective study confirmation.