Endocrine Abstracts

Background

Vascular endothelial growth factor (VEGF) has been implicated in angiogenesis of papillary thyroid carcinoma (PTC). As VEGF expression is increased in PTC and even in lymphocytic thyroiditis (LT), we hypothesized that VEGF may play a role in the development of PTC in patients with LT. In order to find an association between VEGF and these disorders, we examined both the tumoral and adjacent tissues of PTC patients with and without LT.

Methods

Fifty patients with PTC and 17 patients with nodular goiter were, 52.50 7.41 years old (range between 41 and 68), and 50.47 10.38 years old (range between 31 and 67), respectively. According to existing LT within the adjacent tumor tissue, patients with PTC further divided into two groups. The immunohistochemical analyses of VEGF were carried out in both tumor tissue and their adjacent tissue in patients with PTC. For this purpose, each sample was scored: a) for the intensity of the immunostaining and b) for the percentage of the labeled thyrocytes.

Results

The intensity of staining scores and percentage of labeled thyrocytes scores were found to be significantly higher in PTC group than in nodular goiter group (P < 0.001 and P < 0.001, respectively). There was no correlation between VEGF staining scores and age, body mass index, tumor size, tumor subtype, vascular invasion, extrathyroidal extension, and lymph node metastasis in PTC group. In the subgroup analyses of PTC, 17 (34%) patients had LT. The VEGF staining scores in adjacent tumor tissue were statistically significant higher in PTC with LT than in patients without LT (Figure 1). Tumor size, tumor subtype, multifocality, vascular invasion, extrathyroidal extension, and lymph node metastasis were similar in PTC with or without LT.

Conclusion

Our results imply that co-existing LT rises the expression of VEGF in the adjacent tumor tissues of patients with PTC. Future prospective cohort studies are needed to demonstrate whether increased expressions of VEGF is also associated with increased risk of developing PTC in patients with LT.