The uncommon mutations in the EGFR (the epithelial growth factor receptor) gene include a heterogeneous group of genomic alterations within exons 18-21. The clinical response of patients with such mutations to EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment, however, remains unclear. We herein report a case of advanced lung adenocarcinoma harboring complex exon 18 G719X (Gly719Xaa) and exon 20 S768I (Ser768Ile) mutations. The patient started to receive afatinib and has exhibited good response without progression for 12 months. Second-generation EGFR-TKIs might be an optimal treatment option for non-small cell lung cancers harboring these types of rare EGFR mutation.
Keywords: afatinib; non-small cell lung cancer; second-generation TKI; uncommon EGFR mutation.