Repeated radio-ablation therapy with iodine-131 to treat metastatic thyroid cancer can be less effective than the initial round of treatment due to de-differentiation of the cancer cells as the disease progresses.

Glitazones, a class of PPARg drugs capable of re-differentiating the cancer cells, can enhance their I-131 uptake. Long-term use of these agents for treatment of diabetes has been linked to cardiovascular side effects.

Devendra Wadwekar, MD, and coworkers from the University of Utah – Salt Lake City studied the effectiveness of a short, 6-week course of rosiglitazone and pioglitazone prior to radioiodine therapy in patients with metastatic thyroid cancer, including patients whose cancer had spread to the lungs.

According to data presented today at the 81st Annual Meeting of the American Thyroid Association, short-term glitazone treatment caused no side effects. I-131 uptake by metastasized cancer cells in the lung increased significantly compared to no or low uptake in previous rounds of radio-ablation therapy in 38% of patients.

Additionally, thyroglobulin levels were reduced in the blood of all patients that received glitazone pre-treatment, suggesting a decrease in metastatic disease. Long term efficacy and survival remains to be determined.

The 81st Annual Meeting of the American Thyroid Association will be held October 26-30, 2011 at the Renaissance Esmeralda Resort & Spa in Indian Wells, California. This four day creative and innovative scientific program, chaired by Drs. Anthony Hollenberg and Martha Zeiger, has carefully balanced clinical and basic science sessions on the latest advances in thyroidology.

The ATA meeting is designed to offer continuing education for endocrinologists, internists, surgeons, basic scientists, nuclear medicine scientists, pathologists, endocrine fellows and nurses, physician assistants and other health care professionals. Visit for more information.