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

Abstract

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.

Keywords

• carcinomatous meningitis
• epidermal growth factor receptor (EGFR)
• kinase domain duplication
• tyrosine kinase inhibitor (TKI)