Case of a rare EGFR mutation L747P identified using the lung cancer compact Panel™ leading to successful Afatinib treatment

This report describes the case of a 44-year-old Japanese female diagnosed with Stage IA lung adenocarcinoma harboring a rare epidermal growth factor receptor (EGFR) L747P mutation. Conventional polymerase chain reaction (PCR)-based assays did not identify the mutation. Despite undergoing surgery and subsequent chemoradiotherapy, disease recurrence occurred. A computed tomography (CT)-guided lung biopsy revealed the presence of the L747P mutation using the Lung Cancer Compact Panel™. Afatinib therapy was initiated, leading to a significant clinical response and size reduction of metastatic lung lesions. A literature review was conducted to assess the efficacy of afatinib in patients with the L747P mutation and explore the methods available for its detection. This case highlights the utility of the Lung Cancer Compact Panel™ in detecting this unique mutation for targeted therapy.