Association of Clinicopathologic Parameters with the Expression of Inducible Nitric Oxide Synthase and Vascular Endothelial Growth Factor in Mucoepidermoid Carcinoma.

Oral Diseases (2011) 17, 590–596Background: The roles that inducible nitric oxide synthase (iNOS) and vascular endothelial growth factor (VEGF) play in tumorigenesis have been given special attention. In many tumors, their expression is upregulated. In addition, iNOS can stimulate the expression of VEGF. This study was carried out to investigate the expression of iNOS and VEGF as well as their relationship with angiogenesis and the clinicopathological characteristics of mucoepidermoid carcinoma (MEC).Method: The expression of iNOS and VEGF was detected by Streptavidin–peroxidase immunohistochemistry, and microvessel density (MVD) was determined by anti‐CD34 antibody staining in 70 MEC cases and 40 normal salivary gland tissues (NSG). Follow‐up was performed on the 70 patients with MEC. Non‐parametric tests were performed for the comparison of iNOS and VEGF expression.Results: The positive expression rates of iNOS and VEGF were successively enhanced in NSG, well‐differentiated and poorly differentiated MEC (P < 0.05). MVD counts were positively correlated with the expression levels of iNOS and VEGF in MEC (P < 0.05). The expression of iNOS was positively correlated with the expression of VEGF (P < 0.05). iNOS and VEGF expression were significantly associated with tumor differentiation, size metastasis, and relapse (P < 0.05) but were not correlated lymph node metastasis and metastasis.Conclusion: Inducible nitric oxide synthase can stimulate the expression of VEGF, and their expression status may help assess tumor malignancy and patient prognosis.