The dilemma of metastatic medullary thyroid carcinoma: when to start systemic treatment

Two tyrosine kinase inhibitors (TKIs), vandetanib and cabozantinib, have been approved for recurrent/metastatic (R/M) medullary thyroid carcinoma (MTC). To date, it is still debated when and which TKI has to be started in R/M MTC patients. This is due to 1) TKI-related toxicity burden, 2) no overall survival benefit for either TKI, and 3) progression-free survival improvement in MTC subgroups (RETM918T and RAS mutations) treated with...