Anti-angiogenic therapy for high-grade glioma.

This is an updated version of the original Cochrane Review published in September 2014. The most common primary brain tumours in adults are gliomas. Gliomas span a spectrum from low to high grade and are graded pathologically on a scale of one to four according to the World Health Organization (WHO) classification. High-grade glioma (HGG) carries a poor prognosis. Grade IV glioma is known as glioblastoma and carries a median survival in treated patients of about 15 months. Glioblastomas are rich in blood vessels (i.e. highly vascular) and also rich in a protein known as vascular endothelial growth factor (VEGF) that promotes new blood vessel formation (the process of angiogenesis). Anti-angiogenic agents inhibit the process of new blood vessel formation and promote regression of existing vessels. Several anti-angiogenic agents have been investigated in clinical trials, both in newly diagnosed and recurrent HGG, showing preliminary promising results. This review was undertaken to report on the benefits and harms associated with the use of anti-angiogenic agents in the treatment of HGGs.