Efficacy of vandetanib in the treatment of medullary thyroid cancer: literature review and case report

Abstract
Medullary thyroid cancer (MTC) is a rare disorder that accounts for approximately 1.7 % of all thyroid malignancies. MTC is usually detected at early stages; however, approximately 10–15 % of patients are diagnosed with locally advanced MTC and distant metastases. Treatment of such patients is challenging due to biological characteristics of the disease and very few effective treatment approaches available. The investigation of mechanisms of carcinogenesis, as well as advances in pharmacology, allowed the development of a new group of targeted drugs, namely tyrosine kinases, which efficacy against progressive unresectable locally advanced or metastatic MTC has been demonstrated in multiple clinical trials. Vandetanib has been registered for MTC treatment in the Russian Federation. MTC is very rare, thus, each case of vandetanib use for its treatment is particularly interesting. Moreover, since the approval of this drug in 2011 by the U. S. Food and Drug Administration (FDA), new data on the clinical use of vandetanib have been accumulated. Importantly, clinical trials are usually well designed and conducted in near-ideal conditions, whereas the real conditions can be different and patients may have individual characteristics. Therefore, the aim of this study was to update the information on the efficacy and safety of vandetanib by retrospective analysis of available publications and to report a case of MTC treated with vandetanib.