Radiation therapy and antiangiogenic therapy: Opportunities and challenges

The importance of tumoral vascularization as a therapeutic target was first described in 1971 by Folkman. Anarchic vascularization in response to tumour hypoxia, especially mediated by vascular endothelial growth factor, represents a major target in the management of many cancers. The contribution of systemic anti-angiogenic treatments including humanized anti-VEGF monoclonal antibodies (bevacizumab) and tyrosine kinase inhibitors, whose effect on vascular normalization and correction of tumour hypoxia has been shown in preclinical studies to be enhancing the effect of radiotherapy. Early trials combining radiotherapy and antiangiogenics with a small number of patients have contradictory results and tend to put into perspective the opportunity that this synergistic association represents. The efficiency found must be tempered by some toxicity described, especially in association with high doses per fraction. The aim of this article is to present the main studies reporting the efficiency and safety of the combination of antiangiogenic drugs and radiotherapy, as well as the expected opportunities.