In search of a real "targeted" therapy for thyroid cancer.

Over the past 5 years, patients with progressive radioactive iodine-refractory thyroid cancer have responded to "targeted" multikinase inhibitors, which inhibit angiogenesis and not the tumor cell. Here, selumetinib targets the mitogen-activated protein kinase pathway in papillary thyroid carcinoma and shows limited single-agent activity in the patients with tumors that harbor the (V600E)BRAF mutation.