Case report of a patient with stage IV lung adenocarcinoma and uncommon/compound EGFR mutations who responded to afatinib.

There is no established treatment for lung adenocarcinoma with uncommon/compound epidermal growth factor receptor (EGFR) mutations. We report a case of a 73-year-old man with stage IVB lung adenocarcinoma harboring E709G and L861Q EGFR mutations. After 2 months of afatinib treatment, significant tumor shrinkage was observed, and the patient's condition remained stable for 1 year. This case highlights the potential effectiveness of afatinib for treating rare stage IV lung adenocarcinoma with these specific EGFR mutations.