EGFR and non-small cell lung carcinoma: Erlotinib is an orally administered tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR) indicated as first-line treatment for advanced non-small cell lung cancer (NSCLC) in patients with activating EGFR mutations and as second- and third-line treatment in patients with EGFR wild-type NSCLC.