Total regression of brain metastases in non-small cell lung cancer patients harboring EGFR mutations treated with gefitinib without radiotherapy: two case reports

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor. Clinical trials have reported its effectiveness in the treatment of brain metastases from non-small cell lung cancer by overcoming the blood-brain barrier. Gefitinib is generally regarded as a relatively safe agent, and several reports have described its efficacy in patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer and a poor performance status. We herein described two patients with brain metastasis from non-small cell lung cancer who achieved the total regression of metastasis with the administration of gefitinib. A 70-year-old Japanese woman was referred to our hospital with a severe cough. Brain magnetic resonance imaging revealed a metastatic lesion in the left temporal lobe. The tumor was positive for an epidermal growth factor receptor L858R mutation in exon 21 using the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method. She was treated with 250 mg gefitinib per day, and, 1 month later, the primary lesion and brain metastasis had totally resolved. A 58-year-old Japanese woman was referred to our hospital with nausea and headache. Brain magnetic resonance imaging revealed a metastatic lesion in the left cerebellar hemisphere and meningeal dissemination. The tumor was positive for the epidermal growth factor receptor L858R mutation in exon 21. She was treated with 250 mg gefitinib per day, and, 3 weeks later, the primary lesion, brain metastasis, and meningeal dissemination had completely resolved. We successfully treated two lung cancer patients with brain metastasis using gefitinib. Gefitinib therapy may be a suitable treatment for brain metastasis in lung cancer with an epidermal growth factor receptor mutation, particularly in elderly patients with a poor performance status.