EGFR and non-small cell lung carcinoma: Furmonertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has demonstrated systemic and central nervous system (CNS) antitumor activity in patients with EGFR-mutant non-small cell lung cancer (NSCLC); however, evidence supporting its use in patients with diffuse brain metastases after multiple lines of therapy and very poor performance status remains limited.