Immunohistochemical Expression of Potential Therapeutic Targets in Canine Thyroid Carcinoma
Article first published online: 24 FEB 2014
Copyright © 2014 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 28, Issue 2, pages 564–570, March/April 2014
How to Cite
Campos, M., Ducatelle, R., Kooistra, H.S., Rutteman, G., Duchateau, L., Polis, I. and Daminet, S. (2014), Immunohistochemical Expression of Potential Therapeutic Targets in Canine Thyroid Carcinoma. Journal of Veterinary Internal Medicine, 28: 564–570. doi: 10.1111/jvim.12330
- Issue published online: 15 MAR 2014
- Article first published online: 24 FEB 2014
- Manuscript Accepted: 16 JAN 2014
- Manuscript Revised: 5 DEC 2013
- Manuscript Received: 17 SEP 2013
- ECVIM-CA Clinical Studies Fund
- Ghent University. Grant Number: 01J02510
Thyroid carcinoma is a common endocrine tumor in the dog. Local invasive growth frequently precludes surgical excision and, in up to 38% of dogs, the tumor has already metastasized by the time of diagnosis. Therefore, it is important to investigate new treatment modalities that may be useful for the large number of dogs with inoperable tumors or metastatic disease.
To investigate the immunohistochemical expression of potential therapeutic targets in canine thyroid tumors.
74 dogs with thyroid neoplasia.
Immunohistochemistry was performed for thyroglobulin, calcitonin, vascular endothelial growth factor (VEGF), p53, cycloxygenase-2 (cox-2), and P-glycoprotein (P-gp).
Fifty-four (73%) tumors were classified as follicular cell thyroid carcinomas (FTCs) and 20 (27%) as medullary thyroid carcinomas (MTCs). Eighty percent of FTCs and all MTCs had a high percentage (76–100%) of neoplastic cells immunopositive for VEGF. Thirteen percent of FTCs and 50% of MTCs expressed cox-2. Seven percent of FTCs and 70% of MTCs expressed P-gp. No tumor was immunopositive for p53 expression. Expression of VEGF (P = .034), cox-2 (P = .013), and P-gp (P < .001) was significantly higher in MTCs compared to FTCs.
Conclusions and Clinical Importance
VEGF is a potential therapeutic target in both FTC and MTC in dogs. Cox-2 and P-gp may be useful molecular targets in canine MTC.