Associations between Hashimoto Thyroiditis and Clinical Outcomes of Papillary Thyroid Cancer: A Meta-Analysis of Observational Studies

• Main Authors: Shinje Moon, Hye Soo Chung, Jae Myung Yu, Hyung Joon Yoo, Jung Hwan Park, Dong Sun Kim, Young Joo Park
• Format: Article
• Language: English
• Published: Academya Publishing Co. 2018-11-01
• Series: Endocrinology and Metabolism
• Subjects: Hashimoto disease; Thyroid cancer, papillary; Prognosis
• Online Access: https://e-enm.org/Synapse/Data/PDFData/2008ENM/enm-33-473.pdf
• ISSN: 2093-596X; 2093-5978

BackgroundEpidemiological studies have suggested an association between Hashimoto thyroiditis (HT) and papillary thyroid cancer (PTC) development. Other studies, however, have reported a protective role of HT against PTC progression. Through this updated meta-analysis, we aimed to clarify the effects of HT on the progression of PTC.MethodsWe searched citation databases, including PubMed and Embase, for relevant studies from inception to September 2017. From these studies, we calculated the pooled odds ratios (ORs) of clinicopathologic features and the relative risk (RR) of PTC recurrence with 95% confidence intervals (CIs) using the Mantel-Haenszel method. Additionally, the Higgins I2 statistic was used to test for heterogeneity.ResultsThe meta-analysis included 71 published studies with 44,034 participants, among whom 11,132 had HT. We observed negative associations between PTC with comorbid HT and extrathyroidal extension (OR, 0.74; 95% CI, 0.68 to 0.81), lymph node metastasis (OR, 0.82; 95% CI, 0.72 to 0.94), distant metastasis (OR, 0.49; 95% CI, 0.32 to 0.76), and recurrence (RR, 0.50; 95% CI, 0.41 to 0.61).ConclusionIn this meta-analysis, PTC patients with HT appeared to exhibit more favorable clinicopathologic characteristics and a better prognosis than those without HT.