Five-Year Survival Is Similar in Thyroid Cancer Patients with Distant Metastases Prepared for Radioactive Iodine Therapy with either Thyroid Hormone Withdrawal or Recombinant Human TSH

CONTEXT: Elevated levels of TSH markedly enhance the effectiveness of radioiodine (RAI) therapy in metastatic thyroid cancer. OBJECTIVE: The objective of the study was to compare short-term overall survival in thyroid cancer patients with RAI-avid distant metastases prepared for RAI therapy with either traditional thyroid hormone withdrawal (THW) or recombinant human TSH (rhTSH) stimulation. DESIGN: This was a retrospective chart review. SETTING: The study was conducted at a tertiary care comprehensive cancer center. PATIENTS: Patients included 175 patients with RAI avid metastatic disease to lung and/or bone. INTERVENTIONS: In 58 patients, all RAI treatments (remnant ablation and therapy of metastatic disease) were done with rhTSH stimulation. In 35 patients, all RAI treatments were done after THW. In 82 patients, THW was used for initial RAI treatment(s) with subsequent administered activities given after rhTSH stimulation. MAIN OUTCOME MEASURE: Overall survival was measured. RESULTS: After a median follow-up of 5.5 yr, there were no significant differences in overall survival between patients prepared for RAI therapy with rhTSH alone, THW alone, or THW followed by rhTSH (Kaplan-Meier analysis,P = 0.80). In a multivariate analysis that included clinicopathological features and method of preparation (rhTSH or TWH), only age at diagnosis was an independent predictor of overall survival. CONCLUSIONS: Preparation for RAI therapy using either THW or rhTSH stimulation was associated with similar 5-yr overall survival rates in patients with RAI avid thyroid cancer metastases to lung or bone.