Alternative therapeutic approaches in the treatment of primary and secondary dedifferentiated and medullary thyroid carcinoma.

The prognosis of patients with surgically unresectable differentiated thyroid tumors deteriorates significantly if radioiodine therapy is or becomes ineffective, considering the limited role of conventional chemotherapies in these patients. Several alternative approaches have been investigated for the treatment of patients with advanced thyroid malignancies in recent years. Among targeted therapies, tyrosine kinase inhibitors have resulted in the most encouraging responses and could soon be, along with redifferentiation therapy, the possible palliative strategies. Radiopeptide therapy, especially with beta emitter-labeled DOTANOC, which shows a great affinity to the somatostatin receptors expressed by thyroid tumor cells, might also be an attractive approach considering its comparatively low rate of side effects. However, the indication should be evaluated on individual basis. Medullary thyroid carcinoma shows a worse overall prognosis compared with the other differentiated thyroid tumors especially because of its natural resistance to radioiodine therapy. However, among possible palliative strategies, (131)I-meta-iodobenzylguanidine therapy is a noteworthy therapeutic approach in patients experiencing metastasized medullary thyroid carcinoma. In summary, recent developments in the treatment of patients with advanced thyroid malignancies have shown promising results, raising the hope for better outcomes in these patients in future.