Supplementary Material for: Response of Retinoic Acid in Patients with Radioactive Iodine-Refractory Thyroid Cancer: A Meta-Analysis

Purpose: The purpose of this study was to evaluate the
response of retinoic acid (RA) in radioactive iodine (RAI)-refractory
differentiated thyroid cancer (DTC). Methods: Systematic
searches of MEDLINE (from inception to December 2016) and of EMBASE
(from inception to December 2016) were performed for English-language
publications on thyroid cancer treated with RA. Studies were classified
according to the response criteria used: (1) 123I or 131I
whole body scintigraphy (WBS), (2) serum thyroglobulin (Tg) level, (3)
the response evaluation criteria in solid tumors (RECIST) version 1.0,
and (4) World Health Organization (WHO) criteria. Results:
Disease response rates as determined by WBS ranged widely between 6.2%
and 46.1% with a pooled disease response rate of 27.6% (95% confidence
interval: 21.7-34.0%). Response rates as determined by Tg level ranged
from 56.6% to 83.3% (pooled response rate 61.3% (51.0-70.9%)), RECIST
response rates from 0% to 45.5% (pooled response rate 17.0%
(1.4-44.5%)), and according to WHO criteria, the pooled response rate
was 30.8% (12.7-52.7%). Conclusions: A minority of patients with RAI-refractory DTC respond to RA treatment.