Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR; ErbB1) - either exon 19 deletions or exon 21 point mutations - are associated with hypersensitivity to EGFR tyrosine kinase inhibitors (TKIs). EGFR mutations are more frequently found in females, non-smokers, Asians, and patients with adenocarcinoma. We report the case of a 51-year-old Caucasian woman with metastatic NSCLC harboring an EGFR exon 19 deletion although she was a smoker and had a poorly differentiated large cell carcinoma. Following a partial response on 4 months of chemotherapy, the patient progressed and was treated with the reversible EGFR TKI erlotinib for 3 y. The patient then developed resistance to erlotinib and went on to receive the irreversible ErbB Family Blocker afatinib for 1 year, attaining a partial response at 4 months. The impressive survival time attained by our patient highlights the clinical benefit of targeting one or more members of the ErbB Family in patients with disseminated NSCLC and EGFR activating mutations.
Keywords: EGFR mutation; afatinib; case report; non-small cell lung cancer.