Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor (NET), which originates in neural crest-derived calcitonin-producing C-cells. It occurs either sporadically or as a result of a germline mutation in the RET proto-oncogene, as in multiple endocrine neoplasia (MEN) syndrome type 2A including its variant familial MTC (FMTC) and type 2B. Currently, the only curative treatment for MTC is surgery, accompanied by lymph node dissection. However, the outcome is largely dependent on disease staging, with lymph node and distant metastases often identified at diagnosis, particularly in sporadic forms. Furthermore, the presence of cervical lymph node invasion at surgery predicts residual disease. The development of new treatments is strongly motivated by: (a) the low surgical cure rate when cervical lymph node metastases are present at the time of initial surgery, with 90% of patients having residual disease, (b) the high prevalence of distant metastases at initial diagnosis (lungs, bones and liver) and (c) the poor outcome in patients receiving cytotoxic chemotherapeutic agents. Herein, we focus on current nonsurgical options and perspectives in the treatment of MTC with emphasis on last year’s FDA-approved tyrosine kinase inhibitors (TKIs) and other systemic therapies that need to be considered in the setting of advanced disease.
Part of the book: Thyroid Cancer