Importance of Human Papillomavirus Integration in Malignant Transformation of Inverted Papilloma

Abstract

Objectives: This study investigated the role of human papillomavirus (HPV) in malignant transformation of paranasal inverted papilloma (IP). Methods: HPV presence and viral load and physical status of HPV-16 were examined by polymerase chain reaction-based methods using fresh frozen samples or paraffin-embedded samples obtained from 17 patients with IP (IP group), 5 with IP and squamous cell carcinoma (IP+SCC group), 16 with SCC (SCC group), and 67 with chronic inflammatory lesions (inflammatory group). Results: The presence of the HPV genome was detected in 29.4%, 40.0%, 25.0%, and 6.0% of patients in the IP, IP+SCC, SCC, and inflammatory groups, respectively. The IP group showed significantly higher HPV-positive rates than the inflammatory group. All types of HPV detected were high-risk HPV, especially HPV-16. The relative HPV-16 copy numbers varied from 2.5 to 7953 per 50 ng genomic DNA. Viral load was higher in the IP+SCC group than in the inflammatory group. In the IP group, no significant relationship was found between HPV-16 viral load and clinical characteristics. All patients with IP+SCC and SCC showed integration of HPV-16. Conclusions: High viral load and integration of HPV have an important role in malignant lesion in association with IP.