Vascular Endothelial Growth Factor, Plasma
Assessment of tumor progression and prognosis
Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is a homodimeric 34 to 45 kilodalton, heparin-binding glycoprotein. VEGF has potent angiogenic, mitogenic, and vascular permeability-enhancing activities specific for endothelial cells. VEGF is thought to play an important role in several physiologic processes, including wound healing, ovulation, menstruation, maintenance of blood pressure, and pregnancy. VEGF has also been associated with a number of pathologic processes that involve angiogenesis, including arthritis, psoriasis, macular degeneration, and diabetic retinopathy. In general, the growth and spread of tumors has been shown to be dependent on the development of increased vascularization in the tumor vicinity in order to maintain sufficient oxygenation. Tumor expression of proangiogenic factors, including VEGF, has been associated with advanced tumor progression in a number of human cancers. Increased expression of VEGF has been associated with poorer prognosis in patients with cancer of the colon, stomach, pancreas, breast, ovary, prostate, liver, and in oral squamous cell carcinoma and melanoma. Serum VEGF levels are significantly higher than plasma levels. This is thought to reflect the fact that VEGF is released into the plasma from platelets as part of the clotting process. It has been hypothesized that VEGF released from activated platelets may have a role in angiogenesis during wound healing and may also be associated with pathological conditions, such as atherosclerosis, tumor growth, and metastasis formation. In different studies, serum VEGF and plasma VEGF levels have been found to correlate with the clinical status of patients with cancer.
Lavender-top (EDTA) tube
Transfer the plasma into a PP transpak frozen purple tube with screw cap. Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Non-EDTA plasma or serum sent; nonfrozen specimen; hemolysis or gross lipemia