Inducible nitric oxide synthase expression in various laryngeal lesions in relation to carcinogenesis, angiogenesis, and patients' prognosis.

Conclusions: The inducible nitric oxide synthase (iNOS) expression leading to vascular endothelial growth factor (VEGF) overexpression may be useful as a factor for predicting recurrence after initial treatment and prognosis in laryngeal squamous cell carcinoma (SCC). Objective: We analyzed expression of iNOS, p53, and VEGF in various laryngeal lesions. Materials and methods: The study samples consisted of 63 SCC, 20 dysplasia, 7 polyp, and 5 normal epithelium of the larynx. The expression of iNOS, p53, and VEGF was identified by immunohistological methods. Results: No positive immunostaining for iNOS, p53, and VEGF was observed in normal epithelium and polyps. In contrast, with the progression from mild/moderate dysplasia to severe dysplasia to carcinoma, their expression levels increased. In dysplasia, there was a significant positive correlation among expression of iNOS, p53, and VEGF. In SCC, iNOS expression correlated with VEGF overexpression and microvessel density, but not with p53 overexpression. ...