Relationship between vascular endothelial growth factor expression and thyroid stimulating hormone level in benign and malignant thyroid lesions

BACKGROUND: Vascular endothelial growth factor (VEGF) stimulates angiogenesis, increases vascular permeability and seems to correlate to aggressiveness of tumors. Thyroid cancer has been found to have higher levels of VEGF expression. Thyroid stimulating hormone (TSH) is the most important thyroid hormone, yet few researches have been done on its relationship with VEGF. AIM: To study the clinical and demographic profile of thyroid lesions (benign and malignant) and to explored the relationship between VEGF expression (using immunochemistry) and serum TSH level. METHODS: This prospective, observational study includes 61 patients of thyroid lesions who underwent partial, hemi, subtotal or total thyroidectomy as the primary treatment from June 2014 and July 2016. Tissue specimens of thyroid lesions for immunohistochemistry study of VEGF expression were done. Serum TSH was done using Chemiluminiscence technique and correlated to VEGF expression. RESULTS: The mean age of patient was 36.26 ± 11.53 years (range 20-50 years) with female preponderance. Swelling was the most common presenting symptom. Of 61 patients, 37 (60.65%) patients were benign and 24 (39.35%) were malignant thyroid lesions. The mean TSH level in benign group was 1.92 ± 0.94 mIU/liter and malignant group was 2.73 ± 1.74 mIU/liter which was statistically significant (P = 0.023). VEGF expression was strongly positive (3+) in 26 (42.62%) patients and negative/equivocal (1+ & 2+) in 35 (57.38%) patients. In benign group, 10 (27.0%) patients were strongly positive for VEGF whereas in malignant group, 16 (66.7%) patients were strongly positive for VEGF showed significant association (P = 0.002). On comparing TSH level of benign, malignant and total patients separately with VEGF expression, significant association were also observed (P < 0.001, P = 0.004 and P < 0.001, respectively). CONCLUSION: VEGF was strongly expressed in malignant thyroid lesions which are having high serum concentration of serum TSH level. Serum TSH levels reveal a significant correlation with VEGF expression.