Objective: Patients with lung cancer harboring epidermal growth factor receptor (EGFR) mutation respond remarkably well to tyrosine kinase inhibitors of the EGFR (EGFR-TKI). We examined the relation of the EGFR mutation and the efficacy of EGFR-TKI for metastatic brain tumors from lung cancer.
Materials and methods: Forty-one patients with brain metastases from lung cancer were treated in our hospital from January 2007 to October 2010. Among them, 9 patients were examined on their EGFR mutation of tumors using the PNA-LNA PCR clamp method, and were treated with gefitinib, given orally at a daily dose of 250 mg. The drug efficacy for brain tumors was evaluated with MRI and CT.
Results: Seven patients had EGFR mutation (4 in exon 19, and 3 in exon 21). Five patients showed partial response, 3 remained stable, and one had progressive disease. All 5 patients who showed partial response had EGFR mutation. One patient who had progressive disease had no EGFR mutation. Three patients (case 1, 2 and 6) among 5 patients who showed partial response were well controlled only with gefitinib (without radiation).
Conclusion: This study suggests that the efficacy of EGFR-TKI for metastatic brain tumors from lung cancer is related to the EGFR mutation of tumor.