Evaluation of VEGF expression correlates with COX‑2 expression in pleomorphic adenoma, mucoepidermoid carcinoma and adenoid cystic carcinoma

Abstract

Background: Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid
cystic carcinoma (AdCC) are the most common benign and malignant salivary gland tumors.
Cyclooxygenase‑2 (COX‑2) is a key regulatory enzyme that its overexpression in various tumors
is correlated with progression, metastasis, and apoptosis inhibition. Vascular endothelial growth
factor (VEGF) is a potent angiogenic mediator that has an important role in neoplastic angiogenesis.
The aim of this study was to immunohistochemically analyze the expression of COX‑2 and VEGF and
to compare the expression of benign and two malignant salivary gland tumors with varied structures.
Materials and Methods: In this cross‑sectional study, 90 specimens including 30 cases of each
tumor were retrieved. Immunohistochemical staining of COX‑2 and VEGF was performed for all
the samples. The percentage of positive tumor cells and staining intensity was evaluated by two
pathologists blindly. Data were analyzed by Chi‑square and Gamma test and P < 0.05.
Results: A statistically significant difference was noted between the expression and intensity of
COX‑2 and VEGF in PA, MEC, and AdCC (P < 0.05). A significant correlation was observed between
COX‑2 and VEGF expression in MEC and AdCC (P < 0.05). However, no significant correlation was
found between the expression and intensity of COX‑2 and VEGF with histologic grade and lymph
node metastasis in MEC and AdCC (P < 0.05).
Conclusion: High expression of VEGF and COX‑2 in malignant tumors compared to PA suggested the
role of both markers in malignant transformation. The significant correlation of VEGF expression with
COX‑2 may represent the role of COX‑2 in tumor angiogenesis by modulating VEGF production.