Radioactive Iodine Treatment Is Associated with Improved Survival for Patients with Hürthle Cell Carcinoma.

BACKGROUND Hürthle cell carcinoma (HCC) is not typically iodine avid, raising questions regarding postoperative use of radioactive iodine (RAI). The aims of this study were to describe current practice patterns regarding the use of RAI for HCC and to assess its association with survival. METHODS The National Cancer Data Base 1998-2006 was queried for all patients with HCC who underwent total thyroidectomy. Inclusion was limited to T1 tumors with N1/M1 disease, and T2-4 tumors with any N/M disease. Patients were divided into two treatment groups based on receipt of RAI. Baseline patient characteristics were compared between the two groups. Survival was examined using Kaplan-Meier and Cox regression analyses. RESULTS A total of 1909 patients were included. Of these, 1162 (60.9%) received RAI, and 747 (39.1%) did not. Patients treated with RAI were younger (57 vs. 61 years for no RAI, p < 0.001), more often had private insurance (61.7% vs. 53.5% for no RAI, p < 0.003), and were more likely to be treated at an academic center (40.0% vs. 33.1% for no RAI, p < 0.001). Five- and 10-year survival rates were improved for patients who received RAI compared with those who did not (88.9 vs. 83.1% and 74.4 vs. 65.0%, respectively, p < 0.001). RAI administration was associated with a 30% reduction in mortality (hazard ratio = 0.703, p = 0.001). CONCLUSION Present guidelines are inconsistent with regard to indications for using RAI for HCC. This could explain why nearly 40% of HCC patients did not receive RAI. RAI is associated with improved survival, suggesting that it should be advocated for HCC patients with tumors >2 cm and those with nodal and distant metastatic disease.