Evaluation of Serum Angiogenic Factors in Brain Tumor

Abstract

Background: Every temporal process is in a serious need for formation of blood vessels. Neo-vascularization is induced by a variety of factors including vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF). Thyroid hormones also exert angiogenic properties in certain circumstances. We decided to measure the serum level of these factors in patients with glial cell tumors and meningiomas in a case-control study.

Materials and Methods: This study was performed as a case-control study on patients referring to Shiraz Chamran Hospital during 2009-2010 with the diagnosis of either meningioma or glioma. All demographic and clinical data (including age, sex, date of admission and operation, symptoms, family and other pertinent histories, etc.) were also obtained and registered. The volume of the tumor and intraoperative bleeding were recorded. Blood was also drawn from every patient along with some healthy subjects (as controls) to measure the serum level of VEGF, PDGF, FGF and thyroid hormones. Data were analyzed using descriptive statistics, T-test and analysis of variance (one-way ANOVA).Results: Ninety-six patients were enrolled in the study, 32 in each group. There was increased level of VEGF in patients with any cranial tumor, either glioma or meningioma. VEGF levels was highest among grade IV tumors, namely glioblastoma multiforme. VEGF was also higher in larger tumors. There was an increasing trend of serum VEGF levels as glioma grade increased. Highest VEGF levels were seen with parasagittal meningioma. In contrast to VEGF, PDGF was only slightly elevated in glial cell tumors, and it was significantly elevated in patients with meningiomata. Higher serum PDGF correlated with a higher amount of intraoperative bleeding, especially in meningiomas. Oligodendroglial tumors expressed higher PDGF levels in comparison to other glial tumos. No other significant relationship could be found for other factors, including FGF, and thyroid hormones.

Conclusion: We could find an increased serum level of both VEGF and PDGF in CNS tumor patients. A differential role for PDGF was found in the pathogenesis of neovascularization for meningioma, and also for oligodendroglioma. No significant results could be found for FGF and thyroid hormones.

 Key Words: Angiogenesis, Brain Tumor, Meningioma, Glioma, VEGF, FGF, PDGF, Thyroid Hormones