VEGF has been implicated with poor prognosis in breast cancer. Numerous studies show a decreased overall survival and disease-free survival in those tumors overexpressing VEGF. The overexpression of VEGF-A may be an early step in the process of metastasis, a step that is involved in the “angiogenic” switch. Although VEGF-A has been correlated with poor survival, its exact mechanism of action in the progression of tumors remains unclear.

VEGF is also released in rheumatoid arthritis in response to TNF-α, increasing endothelial permeability and swelling and also stimulating angiogenesis (formation of capillaries) It is also important in diabetic retinopathy (DR). The microcirculatory problems in the retina of people with diabetes can cause retinal ischaemia, which results in the release of VEGF-A, and a switch in the balance of pro-angiogenic VEGF isoforms over the normally expressed VEGF isoforms. VEGF may then cause the creation of new blood vessels in the retina and elsewhere in the eye, heralding changes that may threaten the sight.

VEGF plays a role in the disease pathology of the wet form age-related macular degeneration (AMD), which is the leading cause of blindness for the elderly of the industrialized world. The vascular pathology of AMD shares certain similarities with diabetic retinopathy, although the cause of disease and the typical source of neovascularization differ between the two diseases.