Redifferentiation Therapy in Thyroid Cancer

Thyroid cancers of follicular cell origin (papillary and follicular cancers) are usually well differentiated and behave in a non-aggressive manner. However, some lose differentiated functions (dedifferentiation) and behave more aggressively. These cancers are or become refractor Re-differentiating agentsy to thyroid specific therapies that are based on differentiated thyroid function such as radioiodine therapy and TSH suppressive therapy. Restoring differentiated functions in these tumors may both slow tumor growth and also resensitize these thyroid cancers to thyroid specific therapy such as treatment with radioactive iodine. Redifferentiating therapies are tissue specific and generally less toxic than nonspecific chemotherapy. Several redifferentiating agents have been reported to be effective in human thyroid cancers including: (1) retinoids, (2) aromatic fatty acids, (3) peroxisome proliferator-activated receptor gamma (PPARγ) agonists, and (4) histone deacetylase inhibitors.