The association between papillary thyroid carcinoma and histologically proven Hashimoto's thyroiditis: a meta-analysis

ObjectiveNo consensus exists on the association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT). To resolve this controversy, this study aimed to evaluate the relationship between the two conditions using a meta-analysis.MethodsWe searched relevant published studies using citation databases including PubMed, Embase, and ISI Web of Science. The effect sizes of clinicopathologic parameters were calculated by odds ratio (OR), weighted mean difference, or hazard ratio (HR). The effect sizes were combined using a random-effects model.ResultsThirty-eight eligible studies including 10 648 PTC cases were selected. Histologically proven HT was identified in 2471 (23.2%) PTCs. HT was more frequently observed in PTCs than in benign thyroid diseases and other carcinomas (OR=2.8 and 2.4; P