A Pilot Clinical Trial for Poorly Differentiated Thyroid Cancer - Correlation to Retinoid and Peroxisome-proliferator-activated Receptor (PPARy) Expression

This study plans to learn more about a drug called bexarotene for the treatment of advanced thyroid cancer. Subjects are asked to be in this study because they have thyroid cancer that will not respond to radioactive iodine therapy and shows signs of aggressive behavior. Bexarotene has been FDA approved for the treatment of a type of skin cancer called cutaneous T-cell lymphoma, but has not been FDA approved for this use. Bexarotene is investigational in the treatment of thyroid cancer. The purpose of this research study is to test how well the study drug works in humans. The study doctors want to know if: 1. The subjects thyroid cancer gets smaller while you are taking the study drug. 2. The subjects thyroid cancer takes up radioactive iodine better after treatment with the study drug than before treatment.