Approach to the patient with anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma is the least common but most lethal of thyroid cancers. All patients are classified as stage IV, with the primary lesion restricted to the thyroid gland in stage IVA; locoregional lymph nodes may exist in IVA/IVB; and IVC disease is defined by distant metastases. Prognosis is highly dependent on disease extent at presentation, and staging and establishing a plan of care must be accomplished quickly. Although almost all studies are biased due to their retrospective nature, the most important factors associated with longer survival are completeness of surgical resection (achievable in only a minority of patients) and high-dose (>40 Gy) external beam radiotherapy (preferably intensity modulated radiation therapy). Recent reports suggest that a multimodal approach (surgery, radiation, and chemotherapy) is beneficial. Given the high lethality even with apparent local disease, combination systemic therapy (cytotoxics and/or targeted agents) may improve outcomes in stage IVA/IVB patients. Newer, more effective drug combinations are urgently needed for IVC patients who want aggressive therapy. A candid discussion of the prognosis and management options, including palliative care/hospice, should be held with the patient and caregiver as soon as possible after diagnosis to clarify the patient's preference and expectations. Prospective multicenter clinical trials, incorporating molecular analyses of tumors, are required if we are to improve survival in anaplastic thyroid carcinoma.