Aggressive thyroid cancer: targeted therapy with sorafenib.

Sorafenib (Nexavar), is a multikinase inhibitor, which has demonstrated both antiproliferative and antiangiogenic properties in vitro and in vivo, inhibiting the activity of targets present in the tumoral cells (c-RAF [proto-oncogene serine/threonine-protein kinase], BRAF, (V600E)BRAF, c-KIT, and FMS-like tyrosine kinase 3) and in tumor vessels (c-RAF, vascular endothelial growth factor receptor [VEGFR]-2, VEGFR-3, and platelet-derived growth factor receptor β). Sorafenib was initially approved for the treatment of hepatocellular carcinoma and advanced renal cell carcinoma. Experimental studies have demonstrated that sorafenib has both antiproliferative and antiangiogenic properties in vitro and in vivo, against thyroid cancer cells. Furthermore, several completed (or ongoing) studies have evaluated the long-term efficacy and tolerability of sorafenib in patients with papillary, follicular and medullary aggressive thyroid cancer. The results of the different studies showed good clinical responses and stabilization of the disease and suggested that sorafenib is a promising therapeutic option in patients with advanced thyroid cancer that is not responsive to traditional therapeutic strategies (such as radioiodine). Currently, USA Food and Drug Administration has approved the use of sorafenib for metastatic differentiated thyroid cancer.