Therapeutic strategy for non-small-cell lung cancer patients with brain metastases (Review)

Brain metastases are frequently encountered in patients with non-small-cell lung cancer (NSCLC) and are a significant cause of morbidity and mortality. Chemotherapy has been deemed ineffective under the hypothesis that the blood-brain barrier (BBB) limits the delivery of chemotherapeutic agents to the brain. Thus, radiotherapy and occasionally surgery have been selected for the treatment of brain metastases. However, recent clinical data suggested that chemotherapy may be an effective treatment option for patients with brain metastases, since patients who have developed brain metastases may have an inherently compromised BBB. The prognosis of NSCLC patients with brain metastases is generally poor and more effective treatment is required to improve their prognosis. Bevacizumab (Avastin) is a humanized monoclonal antibody that inhibits tumor angiogenesis by neutralizing the vascular endothelial growth factor. Preclinical data indicated that bevacizumab may be effective in preventing as well as treating preexisting brain metastases. Although safety concerns regarding intracranial hemorrhage have been a barrier for the use of bevacizumab in patients with brain metastases, safety data have gradually been accumulated through recent clinical trials. In this review, we aimed to summarize the currently available treatment options and present a therapeutic strategy for NSCLC patients with brain metastases, with a special emphasis on bevacizumab.