Targeting angiogenesis for treatment of NSCLC brain metastases

Lung cancer is the leading cause of cancer-related mortality worldwide, and non-small cell lung cancer (NSCLC) accounts for about 85% of all new lung cancer diagnosis. The majority of people with NSCLC are unsuitable for surgery since most patients have metastatic disease at diagnosis. About 60% of brain metastases arise from lung cancer. Therapeutic approaches to brain metastases include surgery, whole brain radiotherapy (WBRT), stereotactic radiosurgery, chemotherapy and new biologic agents. Angiogenesis is essential for the development and progression of cancer, and vascular endothelial growth factor (VEGF) is a critical mediator of tumour angiogenesis. One of the targeted approaches most widely studied in the treatment of NSCLC is the inhibition of angiogenesis. Bevacizumab, an anti-VEGF recombinant humanized monoclonal antibody, is the first targeted agent which, when combined with chemotherapy, has shown superior efficacy versus chemotherapy alone as first-line treatment of advanced non-squamous NSCLC patients. Patients with central nervous system (CNS) metastases have initially been excluded from bevacizumab trials for the risk of cerebral haemorrhage as a result of the treatment. Nevertheless, the available data suggest an equal risk of intracranial bleeding in patients with CNS metastases treated with or without bevacizumab therapy. Several other anti-angiogenetic drugs are being investigated in the treatment of advanced NSCLC patients, but results of their activity specifically in CNS metastases are still lacking. This review will focus on the potential role of bevacizumab and other anti-angiogenetic agents in the treatment of brain metastases from NSCLC.