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


METHODS
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.


METHODS
For patients assigned to group A, L-T(4) was administered to keep serum TSH levels below 0.01 μU/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.
Sugitani
Iwao
I
Division of Head and Neck, Cancer Institute Hospital, Koto-ku, Tokyo, Japan. isugitani@jfcr.or.jp
Fujimoto
Yoshihide
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000188:drug therapy* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012008:Recurrence; D013963:Thyroid Hormones / Q000008:administration & dosage / Q000627:therapeutic use*; D013964:Thyroid Neoplasms / Q000188:drug therapy* / Q000601:surgery*; D013972:Thyrotropin / Q000037:antagonists & inhibitors*; D054928:Validation Studies as Topic; D055815:Young Adult
D013963:Thyroid Hormones; D013972:Thyrotropin