Management of the patient with progressive radioiodine non-responsive disease.

Differentiated thyroid cancer accounts for a majority of the nearly 200,000 people in the United States with thyroid cancer. A significant minority of patients with thyroid cancer do not respond to conventional therapy (surgery, radioiodine, levothyroxine [LT4]). Current therapy for progressive, radioiodine non-responsive differentiated thyroid cancer includes surgery and external-beam irradiation (with or without low-dose weekly Adriamycin) for neck disease, and high-dose Adriamycin therapy for widely metastatic disease. Adriamycin therapy provides a 30% to 40% partial response of disease, but long-term cures are rare. Studies of combination chemotherapy do not show greater benefit than therapy with Adriamycin alone and carry understandably greater toxicity. Retinoic acid, octreotide, and tamoxifen therapies are currently being studied as future therapeutic possibilities. Chemotherapy may prove useful not only as a tumoricidal agent but as therapy for tumor re-differentiation in preparation for radioiodine therapy.