Update on the use of angiogenesis inhibitors in adult patients with brain tumors.

The outcome following conventional therapy for patients with primary and metastatic brain tumors remains poor. Most primary brain cancers are angiogenic, and much research has targeted angiogenesis therapeutically. Vascular endothelial growth factor drives angiogenesis in brain tumors, although other factors contribute. Aggregate data confirm that the safety profile of antiangiogenic agents is acceptable among patients with brain cancer; the risks for serious adverse events, such as stroke, hemorrhage, and thrombosis, are low and similar to those observed in other cancers. Evidence of antitumor activity includes encouraging rates of radiographic response and progression-free survival. In addition, the potent antipermeability effects of these agents can substantially reduce cerebral edema and corticosteroid requirement. Importantly, most data demonstrate that antiangiogenic agents preserve neurologic function and improve quality of life. Unfortunately, the impact of angiogenesis inhibition on overall survival appears to be modest at best in patients with brain cancer. In addition, mechanisms of resistance, including selection favoring invasion, remain poorly understood.