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

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.