Durable response to EGFR tyrosine kinase inhibitors in a patient with non–small cell lung cancer harboring an EGFR kinase domain duplication

• Main Authors: Esuteru Hirokawa, Satomi Watanabe, Kazuko Sakai, Masayuki Takeda, Chihiro Sato, Takayuki Takahama, Kazuto Nishio, Kazuhiko Nakagawa
• Format: Article
• Language: English
• Published: Wiley 2021-08-01
• Series: Thoracic Cancer
• Subjects: carcinomatous meningitis; epidermal growth factor receptor (EGFR); kinase domain duplication; tyrosine kinase inhibitor (TKI)
• Online Access: https://doi.org/10.1111/1759-7714.14081
• ISSN: 1759-7706; 1759-7714

Abstract Epidermal growth factor receptor (EGFR) kinase domain duplication (KDD) has been identified as an oncogenic driver in 0.05% to 0.14% of non–small cell lung cancer (NSCLC) patients. However, little is known of the efficacy of EGFR tyrosine kinase inhibitors (TKIs) for such patients. Here, we report the case of a 45‐year‐old Japanese woman with NSCLC positive for EGFR‐KDD (duplication of exons 18–25) who developed carcinomatous meningitis and showed a marked response to the EGFR‐TKIs erlotinib and osimertinib. As far as we are aware, this is the first report of EGFR‐TKI efficacy for carcinomatous meningitis in a NSCLC patient harboring EGFR‐KDD.