Update and developments in the treatment of glioblastoma multiforme - focus on bevacizumab

Glioblastoma is the most common primary brain tumor with a relatively poor prognosis. This article reviews the current standard therapy and discusses new developments in treatment of this disease. Surgical resection followed by radiation and chemotherapy has proven to be the most effective initial therapy. Recent advancement in molecular targeted therapies has led to the Food and Drug Administration (FDA) approval of bevacizumab in the setting of recurrent glioblastoma. The molecular pathways of glioblastoma growth are highlighted in this review. While numerous molecular targets are currently being intensely investigated, vascular endothelial growth factor (VEGF) receptor targeted therapy has been the only one to have shown clinical effect. The role of bevacizumab in this context provides a dynamic breakthrough in cancer therapy. Clinical trials have demonstrated significantly increased overall survival and six month progression free survival (PFS) in recurrent glioblastoma treated with bevacizumab alone or in combination with irinotecan. The use of this agent has also dramatically changed the imaging characteristics of glioblastoma. The anti-angiogenesis effects of bevacizumab have complicated the criterion for determining tumor growth. This may lead to redefinition of progressive disease based on non-invasive monitoring.