Targeted therapy in radioiodine refractory thyroid cancer.

The majority of differentiated thyroid carcinomas (DTCs) of follicular cell origin are cured with adequate surgical management and radioiodine therapy. Other thyroid malignancies such as medullary thyroid carcinoma (MTC) or poorly differentiated thyroid carcinomas frequently metastasize, precluding patients from a curative resection. Therapeutic options for these patients include additional surgery for resectable lesions, external radiotherapy and chemotherapy. The results of this approach is usually disappointing and the use of novel therapeutic approaches is needed. The outstanding progress in the molecular basis of thyroid carcinoma offered the tool for the development of new drugs, mainly tyrosine-kinase inhibitor and inhibitors of proangiogenic factors, which are currently in phase II or III clinical trials with promising results (the so called targeted therapy). This review will summarize the most relevant achievements in the field and will discuss the limit and perspective of the new compounds.