Mesenchymal-epithelial Transition Exon 14-skipping Mutation-positive Invasive Mucinous Adenocarcinoma of the Lung: First Case Treated with Mesenchymal-epithelial Transition-tyrosine Kinase Inhibitors

• Published in: Internal Medicine Vol. 63; no. 12; pp. 1789 - 1795
• Main Authors: Okuzumi, Shinichi, Suzuki, Hiraku, Morinaga, Shojiroh, Tamura, Masaki, Minematsu, Naoto
• Format: Journal Article
• Language: English
• Published: Tokyo The Japanese Society of Internal Medicine 15.06.2024; Japan Science and Technology Agency
• Subjects: Adenocarcinoma; Alveoli; Autopsy; c-Met protein; Fibrosis; interstitial lung disease; invasive mucinous adenocarcinoma; Invasiveness; Lung diseases; mesenchymal-epithelial transition factor; MET exon 14 skipping mutation; Mutation; tepotinib; Toxicity; Tyrosine kinase inhibitors
• ISSN: 0918-2918; 1349-7235; 1349-7235
• DOI: 10.2169/internalmedicine.2540-23

Mesenchymal-epithelial transition (MET) exon 14-skipping mutation (METex14) is rare in pulmonary invasive mucinous adenocarcinomas (IMAs), and the clinical impact of MET-tyrosine kinase inhibitors (TKIs) remains unknown. We herein report a 75-year-old woman with IMA harboring METex14 who was treated with the MET-TKI tepotinib. The lung tumor regressed over six months; however, the patient ultimately died of exacerbated interstitial lung disease (ILD), possibly associated with tepotinib. An autopsy revealed diffuse alveolar damage in pre-existing chronic fibrosis. We discuss how to pre-evaluate ILD deterioration risks and monitor TKI-induced lung toxicity during treatment.