Does postoperative thyrotropin suppression therapy truly decrease recurrence in papillary thyroid carcinoma? A randomized controlled trial.

Author(s): Sugitani I, Fujimoto Y

Affiliation(s): Division of Head and Neck, Cancer Institute Hospital, Koto-ku, Tokyo, Japan. isugitani@jfcr.or.jp

Publication date & source: 2010-10, J Clin Endocrinol Metab., 95(10):4576-83. Epub 2010 Jul 21.

Publication type: Randomized Controlled Trial; Research Support, Non-U.S. Gov't

CONTEXT: TSH suppression therapy has been used to decrease thyroid cancer recurrence. However, validation of effects through studies providing a high level of evidence has been lacking. OBJECTIVE: This single-center, open-label, randomized controlled trial tested the hypothesis that disease-free survival (DFS) for papillary thyroid carcinoma (PTC) in patients without TSH suppression is not inferior to that in patients with TSH suppression. DESIGN: Participants were randomly assigned to receive postoperative TSH suppression therapy (group A) or not (group B). Before assignment, patients were stratified into groups with low- and high-risk PTC according to the AMES (age, metastasis, extension, size) risk-group classification. INTERVENTIONS AND OUTCOME MEASURES: For patients assigned to group A, L-T(4) was administered to keep serum TSH levels below 0.01 muU/ml. TSH levels were adjusted to within normal ranges for patients assigned to group B. Recurrence was evaluated by neck ultrasonography and chest computed tomography. RESULTS: Eligible participants were recruited from 1996-2005, with 218 patients assigned to group A and 215 patients to group B. Analysis was performed on an intention-to-treat basis. DFS did not differ significantly between groups. The 95% confidence interval of the hazard ratio for recurrence was 0.85-1.27 according to Cox proportional hazard modeling, within the margin of 2.12 required to declare 10% noninferiority. CONCLUSIONS: DFS for patients without TSH suppression was not inferior by more than 10% to DFS for patients with TSH suppression. Thyroid-conserving surgery without TSH suppression should be considered for patients with low-risk PTC to avoid potential adverse effects of TSH suppression.