Significance of vascular endothelial growth factor and epidermal growth factor in development of papillary thyroid cancer.

BACKGROUND AND AIMS: Vascular endothelial growth factor (VEGF) induces proliferation of endothelial cells, stimulates angiogenesis and increases vascular permeability. Epidermal growth factor (EGF) induces proliferation of epidermal cells and stimulates epidermal migration. Increased VEGF and EGF expression have been associated with poor clinical outcome in many malignancies. Several recent reports have shown overexpression of VEGF and EGF in papillary thyroid cancer (PTC). The study aimed to determine the intensity of expression of VEGF and EGF in patients with PTC and to find any correlation between the intensity of the expression and staging of the disease at the moment of surgery PATIENTS AND METHODS: The study comprised a group of 48 consecutive patients with PTC who underwent radical surgery. The group consisted of 11, 25, eight and four patients at pT1N0M0, pT2N0M0, pT3N1M0 and pT4N1M0 stages, respectively. The control group was composed of 20 healthy bone marrow transplant donors, age-, gender- and BMI-matched with PTC patients. The immuno-chemiluminescence enzyme linked immunoassay (ELISA) method was used to determine the expression and level of VEGF and EGF in serum samples. Patients' characteristics, serum levels of VEGF and EGF, final histology and pTNM were analysed.
RESULTS: The mean serum level of VEGF and EGF was remarkably higher in PTC patients than in controls. A negative correlation between staging in pTNM classification and the mean serum VEGF level (r=-0.5168; P<0.05) as well as a positive correlation between staging in pTNM classification and the mean serum EGF level (r=0.6104; P<0.05) in PTC patients was observed.
CONCLUSIONS: Both VEGF and EGF play an important role in PTC growth. However, the intensity of their expression is variable, depending on the stage of the disease. The highest intensity of VEGF expression is characteristic for low-stage T1N0M0 disease, whereas the highest intensity of EGF expression is more often found at locally advanced pT3 and pT4N1M0 stages of the disease. Further long-term follow-up studies are required to demonstrate the prognostic value of VEGF and EGF in PTC, particularly in identification of patients with expected poor prognosis or shorter recurrence-free survival.