Angiogenesis and vascular endothelial growth factors in intraocular tumors.

The role of angiogenesis in tumors appears obvious: without vessels, tumors cannot grow. However, the long-held belief that all human solid tumors are angiogenesis-dependent has been challenged by the universally disappointing results of anti-angiogenesis therapy in cancer. This may be explained by the fact that cooption of preexisting vasculature as a primary or secondary mechanism of tumor vascularization is more important than previously thought. Nevertheless, anti-angiogenesis therapy may play an important (adjuvant) role in the prevention of metastases of intraocular tumors (uveal melanoma and retinoblastoma). Antivascular endothelial growth factor therapy already plays an important role in the management of irradiation complications in tumor eyes.