Elevated Vascular Endothelial Growth Factor (VEGF) levels in the blood serum of dogs with malignant neoplasms of the oral cavity

Angiogenesis plays an essential role in the development of a neoplastic tumour by conditioning both its growth and the formation of metastases. The induction of blood vessel growth occurs under the influence of proangiogenic factors, among which Vascular Endothelial Growth Factor (VEGF) seems to be the most important. The aim of this research was to study the level of VEGF measured by ELISA in the serum of dogs with neoplasms of the oral cavity. The study material comprised samples of neoplastic tissue from 17 operated dogs and the serum of the examined animals as well as of dogs from the control group. The tissue samples were taken from dogs of different breeds, aged 6–14 years. The tumour type was determined in accordance with the applicable WHO classification. Blood samples taken from sick dogs and from animals of the control group were centrifuged, and immunoenzymatic labelling of VEGF was performed in the obtained serum using ELISA and R&D system reagents (Quantikine Canine VEGF). All stages of VEGF labelling were performed according to the recommendation of the test manufacturer. The median of VEGF in the serum of the dogs with neoplasms of the oral cavity was 40.64 pg/mL. The lowest value of 14.26 pg/mL was observed in the case of fibrosarcoma, and the highest value of 99.19 pg/mL in the case of squamous cell carcinoma. The VEGF median in the control group amounted to 11.14 pg/mL whereas the VEGF value in the groups of animals diagnosed with benign tumours ranged between 2.30 and 19.74 pg/mL. Elevated VEGF in the blood serum, in comparison with the benign tumour group and the control group, was observed in all examined neoplasms of the oral cavity. It was suggested that overexpression of VEGF can have a prognostic value and is useful in the early detection of neoplasms