Recent Updates on the Management of Medullary Thyroid Carcinoma.

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor derived from the thyroid C cells producing calcitonin. MTC accounts for 0.6% of all thyroid cancers and incidence of MTC increased steadily between 1997 and 2011 in Korea. It occurs either sporadically or in a hereditary form based on germline rearranged during transfection (RET) mutations. MTC can be cured only by complete resection of the thyroid tumor and any loco-regional metastases. The most appropriate treatment is still less clear in patients with residual or recurrent disease after initial surgery or those with distant metastases because most patients even with metastatic disease have indolent courses with slow progression for several years and MTC is not responsive to either radioactive iodine therapy or thyroid-stimulating hormone suppression. Recently, two tyrosine kinase inhibitors (TKIs), vandetanib and cabozantinib, are approved for use in patients with advanced, metastatic or progressive MTC. In this review, we summarize the current approach according to revised American Thyroid Association guidelines and recent advances in systemic treatment such as TKIs for patients with persistent or recurrent MTC after surgery.