Angiogenic Factors in Adult Diffuse Glioma and Their Correlation With Tumor Grade: An Observational Study

Background Angiogenesis is responsible for the growth, progression, and metastasis of adult diffuse gliomas and other solid tumors. Vascular endothelial growth factor (VEGF) acts as both a pro-angiogenic and a potent angiogenic cytokine, playing a significant role in cell proliferation and endothelial cell permeability. Gliomas are characterized by vascular proliferation, which is responsible for tumor growth and biological behavior and disease outcome. CD34 is a transmembrane phosphoglycoprotein and a pan-endothelial marker that can help examine microvessel density (MVD), a measure used to assess the vascular response to VEGF. Materials and methods The present cross-sectional study, conducted on 50 histopathologically proven cases of adult diffuse glioma, was carried out to understand the angiogenic phenomenon by measuring VEGF activity and MVD. These were morphologically graded based on the Central Nervous System (CNS) World Health Organization (WHO) grading system. Immunohistochemical staining for the anti-VEGF antibody was performed to examine the expression of VEGF and scored from 0 to 3. MVD was evaluated through CD34 immunohistochemical staining. Both angiogenic factors were subsequently correlated with the tumor's histological grade. Results VEGF expression was observed in 44 of the total 50 cases of adult diffuse glioma. Overexpression was seen to be strongly correlated with higher tumor grade. Most cases revealed higher MVD that ranged from 15 to 105 microvessels/10 high-power fields (hpf). MVD was also compared with tumor grades, exhibiting a higher MVD value with increasing tumor grade in cases of adult diffuse glioma.  Conclusion Angiogenic response factors such as VEGF expression and MVD played a significant role in adult diffuse glioma progression. Its understanding, therefore, is of vital importance so that the option of personalized therapeutic strategies can be explored and the patient can benefit from the targeted treatment options against VEGF. It is expected to potentially decrease tumor growth and progression and disease burden, thereby improving overall survival outcomes in high-grade glioma and bringing a ray of hope to these patients.