Chronic Periodontitis-Human Papillomavirus Synergy in Head and Neck Cancers

Objectives: Human papillomavirus (HPV) plays a significant role in head and neck cancers (HNCs). However, the majority of HPV infections are transient and do not cause malignancy. Persistent HPV infection is a central risk factor for carcinogenesis. Identification of factors for HPV's persistence is critical to facilitate prevention of HNCs. The aim of this study was to compare the history of chronic periodontitis in patients with HPV+ and HPV- tumors. Methods: We performed a case-control study. The study population was derived from the Department of Dentistry and Maxillofacial Prosthetics, Roswell Park Cancer Institute, Buffalo, NY. All patients newly diagnosed with primary base of tongue squamous cell carcinoma (SCC) between 1999 and 2005 who had data available to assess both HPV and periodontitis status were included. Cumulative history of periodontitis was assessed by alveolar bone loss (ABL) from panoramic radiographs. Periodontitis was defined as ABL ≥2.75 mm. HPV-16 DNA was identified by PCR from paraffin-embedded tumor samples blind to periodontal status. T-test for continuous and chi-square test for categorical variables were used to test the differences between HPV+ and HPV- tumors. Results: A total of 23 cases of base of tongue SSC were available. The prevalence of HPV-16 positive tumors was 15/23 (65.2%). The prevalence of subjects with periodontitis was 14/21 (66.6%). Two subjects (8.7%) were edentulous. Compared to subjects with HPV- tumors, subjects with HPV+ tumors had significantly higher prevalence of periodontitis (p=0.002) and higher mean alveolar bone loss (2.56 mm vs. 3.94 mm, p=0.023). Patients with HPV+ tumors were also younger (62.63 vs. 57.07, p=0.183), had higher proportion of men (p=0.181) and nonsmokers (p=0.065) although these differences did not reach statistical significance. Conclusion: History of periodontitis seems to be strongly associated with tumor HPV status. These results need to be confirmed by larger studies including other HNC sites. 5R03CA119262-02.