Re-differentiation of well-differentiated thyroid cancer: An educational exhibit from retinoic acid to rosiglitazone

Learning Objectives 1. To review the various groups of drugs (e.g. retinoic acids, thiazolidinediones inhibitors of methylation, histone acetylators, and HMG-CoA reductase inhibitors) that have been used or are presently being evaluated to re-differentiate thyroid cancer cells that have lost their ability to take up radioiodine. 2. To discuss the proposed mechanisms of these drugs. 3. To describe proposed administrative schedules. 4. To present the clinical success of these drugs in animals and humans. 5. To list potential side effects and frequency. 6. to list known clinical trials underway within the United States.

Summary: In patients with well-differentiated thyroid cancer (WDTC), the thyroid cancer cells may lose their ability to take up radioiodine (e.g. de-differentiation), and frequently, these cancer cells are more aggressive with a worse prognosis. Unfortunately, the use of radioiodine for the diagnosis and treatment is no longer effective or has reduced effectiveness. In order to restore or increase the uptake of radioiodine in these patients, multiple drugs have been used or are being evaluated to “re-differentiate” these thyroid cancer cells. Examples of the various groups of these drugs are noted above, and this educational exhibit will review the literature regarding these groups of drugs, their proposed mechanisms, the various administration schedules, their clinical success to date in animals and humans, and potential side effects. The exhibit will conclude with a list of known clinical trials with contact information.