Metformin Decreases Serum Thyroglobulin Concentration in Nonmedullary Thyroid Carcinoma.

Context: The conventional treatment of nonmedullary thyroid carcinoma (NMTC) includes surgical resection, thyrotropin (TSH) suppression, and 131-iodine. Some patients develop persistent/recurrent metastatic disease requiring expensive alternative therapies, such as external radiation and multikinase inhibitors, which may have clinically significant side effects. Recent in vitro studies, in vivo studies in animals, and association studies in humans suggest that metformin, an inexpensive medication with a modest side effect profile, may help prevent or treat NMTC.