Management of Undifferentiated (Anaplastic) Thyroid Cancer

Abstract Undifferentiated (anaplastic) thyroid cancer (ATC) is the rarest yet most aggressive thyroid cancer. Most patients present with a rapidly enlarging thyroid mass, and the majority die within 6 months of diagnosis. ATC commonly occurs from dedifferentiation of a previously well-differentiated thyroid cancer, though it may arise de novo in some cases. Optimal management of ATC involves a multidisciplinary approach with a combination of surgery, radiotherapy, chemotherapy, and most recently, immunotherapy, to provide the best quality of life with the longest survival. Despite advances in ATC management, there is still much work ahead to improve survival for this lethal disease.