// Wei Dai 1, * , Yu-Tuan Wu 2, * , Xin Li 2, * , Yan-Ling Shi 2, * , Lu Gan 3 , Hong-Yuan Li 2 , Guo-Sheng Ren 2 , Kai-Nan Wu 2 and Ling-Quan Kong 2 1 Department of Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China 2 Department of Endocrine and Breast Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China 3 Department of Oncology and Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China * These authors contributed equally to this work Correspondence to: Ling-Quan Kong, email: huihuikp@163.com Keywords: hepatitis B core antibody; hepatitis B virus; past infection; thyroid carcinoma; thyroid stimulating hormone Received: July 12, 2017 Accepted: December 05, 2017 Published: January 02, 2018 ABSTRACT Objective: To explore whether thyroid carcinoma is associated with the infection of hepatitis B virus. Results: Although there were no differences on the positive rates of Hepatitis B surface antigen and hepatitis B surface antibody in the thyroid carcinomas group (8.67% & 59.24%) and control group (8.86% & 58.21%, p > 0.05), the positive rate of hepatitis B core antibody in thyroid carcinomas group (55.71%) was significantly lower than that in the control group (63.28%, p = 0.0004). Through the logistic regression analysis, compared to the control group, the rate of hepatitis B core antibody seropositivity was lower in thyroid carcinomas group in whole cases ( Adjusted OR = 0.82, 95% CI 0.69–0.98, p = 0.0337). In addition, compared to the control group, a more interesting result was found that the adjusted OR value of hepatitis B core antibody seropositivity of male is lower than female in statistics ( Adjusted OR = 0.62, 95% CI 0.41–0.94, p = 0.0237; Adjusted OR = 0.89, 95% CI 0.72–1.08, p > 0.05, respectively). Conclusions: The rate of hepatitis B core antibody seropositivity in thyroid carcinoma patients is lower than that in controls and the past hepatitis B virus infection may be a weak protective factor for the development of thyroid carcinoma. Methods: In this study, the clinical data of 2134 patients with initially diagnosis of thyroid nodules while receiving surgery, with the reports of hepatitis B virus serological markers in single center from June 2010 to September 2015, were collected for comparative analysis. Of all there were 1050 (49.20%) cases of thyroid carcinomas group and 1084 (50.80%) noncancerous thyroid nodules group.