Consensus on management of advanced medullary thyroid carcinoma on behalf of the Working Group of Thyroid Cancer of the Spanish Society of Endocrinology (SEEN) and the Spanish Task Force Group for Orphan and Infrequent Tumors (GETHI)

Of all thyroid cancers, < 5 % are medullary (MTC). It is a well-characterized neuroendocrine tumor arising from calcitonin-secreting C cells, and RET gene plays a central role on its pathogeny. The electronic search was conducted using MEDLINE (PubMed), EMBASE and Cochrane Central Register of Controlled Trials. Quality assessments of selected current articles, guidelines and reviews of MTC were performed. This consensus updates and summarizes biology, treatment and prognostic considerations of MTC. Multidisciplinary teams and specialized centers are recommended for the management of MTC patients. In the metastatic setting, those patients with large volume of disease are candidates to start systemic treatment mainly if they are symptomatic and the tumor has progressed in the last 12-14 months. Wait and see strategy should be offered to patients with: disseminated disease with only high levels of calcitonin and no macroscopic structural disease, low burden and absence of progression.