Detection of Human Papillomavirus in Papillary Thyroid Carcinoma and its Association with Tumor Staging and Pathologic Features.

Background: The role of human papillomavirus (HPV), as a common infection, has been evaluated in many cancers such as the cervix and squamous cell carcinoma of the head and neck. To the best of our knowledge, for the first time, the association of HPV with papillary thyroid carcinoma (PTC) and its pathologic features are investigated. Methods: A retrospective cross-sectional study was conducted from May 2014 to January 2018 in several hospitals affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. Thyroid tissue specimens of patients diagnosed with PTC (n=82) and benign thyroid nodules (n=77) were collected using the consecutive sampling method. The presence of HPV in PTC, adjacent normal tissue, and benign thyroid nodules was evaluated using the polymerase chain reaction (PCR) method. The frequency of HPV positivity in PTC tissues was compared with benign thyroid nodules and adjacent normal tissue. Association of pathologic features of PTC with HPV positivity was also investigated. Data were analyzed using SPSS version 21.0, and P values less than 0.05 were considered statistically significant. Results: HPV PCR positivity was observed in 3.8% of benign thyroid nodules and 13.4% of PTC samples but in none of the adjacent normal tissues. After adjustment for age and sex, the prevalence of HPV PCR positivity in the PTC tissues was significantly more than the benign thyroid nodules (P=0.015). The prevalence was also significantly higher than the adjacent normal tissues (P<0.001). Conclusion: There was a significant association between PTC and HPV positivity. Further studies are required to determine the cause and effect of the association between these two conditions.