Angiogenesis in astrocytomas: An immunohistochemical study of VEGF, factor VIII, and COX-2 expression

摘要

Background & aim: Astrocytomas are histologically classified into grades I through IV on the basis of cellularity, nuclear atypia, mitotic activity, pseudopalisading necrosis and/ or microvascular proliferation. Angiogenesis plays an important role in the growth and progression of asrtocytomas that exhibit marked and aberrant blood vessel formation indicating angiogenic endothelial cells as a potential target for tumor treatment . Materials & methods: This work was designed to study the role of angiogenesis in the growth and progression of astrocytomas, by studying the immunohistochemical expression of vascular endothelial growth factor (VEGF), factor VIII, and Cyclooxygenase-2 (COX-2) on 78 retrospective cases of astrocytoma. Results: VEGF immunoreactivity was detected 87.2% of the studied cases, while 82.1% of the studied cases showed positive COX-2 expression. The expression of both VEGF and COX-2 showed significant increase with increasing tumor grade (p 0.05). The relationship between the tumor grade and microvascular density (MVD) increased significantly (p 0.05). A significant positive correlation was observed between the immunoreactive scores of VEGF, COX-2, and MVD (p 0.05). Conclusion: The increase in VEGF expression and MVD in astrocytomas indicates the significant role of angiogenesis in their development and progression. The significant positive association between VEGF expression, MVD, and COX-2 expression suggests that COX-2 contributes to angiogenesis in astrocytomas possibly by upregulation of VEGF.