Salivary levels and immunohistochemical expression of selected angiogenic factors in benign and malignant parotid gland tumours.

Objectives: Angiogenesis underlies tumour growth and metastasis through hepatocyte growth factor (HGF), epithelial growth factor (EGF), and vascular endothelial growth factor (VEGF). The aim of this study was to determine the levels of VEGF, EGF, HGF, HGFR (hepatocyte growth factor receptor), and SRSF1 (serine-rich protein splicing factor-1) in patients with parotid gland tumours and in healthy controls via ELISA in parotid saliva. Immunohistochemical expression of anti-angiogenic isoform of VEGFb subunit, VEGFR1, VEGFR2, and microvessel density (CD34) were assessed in the tumour tissue and in the non-tumorous surrounding margins.

Materials And Methods: The study included 48 patients with benign and malignant parotid gland tumours and 15 healthy controls.

Results: Comparison of VEGF, EGF, and HGF in tumour and non-tumorous tissues showed no significant differences and no correlations with tumour stage. The salivary VEGF concentration was significantly higher in patients with pleomorphic adenoma and Warthin's tumour. No significant correlation was found between expression of VEGFb and VEGFR2 in tumours and non-tumor surgical margins.

Conclusions: The increased salivary VEGF reflects changes in affected parotid glands, but it cannot be used as a prognostic and differentiative factor for parotid tumours.

Clinical Relevance: Reciprocal relations between growth factors suggest an overlapping pathway of secretion and activity.