Chapter 6 - Brain Metastases from Non-Small Cell Lung Cancer: Current Evidence in Management Using Tyrosine Kinase Inhibitor and Whole-Brain Radiation Therapy

Abstract

Lung cancer is one of the leading causes of cancer-related mortality worldwide, and significant percentage of patients with lung adenocarcinoma will develop brain metastases during their lifetime. Whole-brain radiation therapy (WBRT) remains the standard of care in patients with multiple brain metastases from non-small cell lung cancer (NSCLC). Prognosis after WBRT remains poor. Epidermal growth factor receptor (EGFR) mutations are found in about 10–15% of patients with NSCLC, and in up to 50% of patients with brain metastasis. Erlotinib, gefitinib, and afatinib are tyrosine kinase inhibitors (TKIs) that have demonstrated higher response rate and longer progression-free survival in patients with NSCLC and EGFR mutations compared to conventional chemotherapy. TKI used as monotherapy for brain metastases from lung adenocarcinoma has shown intracranial response rates ranging between 74% and 87% and is a safe and effective option that needs further exploration. Studies have demonstrated a probable benefit in combining TKI with WBRT in treatment of brain metastases from lung adenocarcinoma. A few studies have raised concerns regarding the toxicity of the combination therapy and caution should be exercised in their concurrent use.