Chronic periodontitis-human papillomavirus synergy in base of tongue cancers

Objective: To assess whether chronic periodontitis history predicts human papillomavirus (HPV) status in patients with base of tongue cancers. Design: Case-control study using existing patient data. Setting: Roswell Park Cancer Institute. Patients: Thirty patients newly diagnosed with base of tongue squamous cell carcinoma between 1999 and 2005 for whom both tumor samples and periodontal records were available. Patients younger than 21 years, edentulous, immunocompromised, and those with a history of cancer were excluded. Periodontitis history was assessed on the basis of alveolar bone loss (in millimeters) from panoramic radiographs by one examiner who was blinded to cancer status. Main Outcome Measure: HPV-16 and HPV-18 DNA were identified on paraffin-embedded tumor samples by polymerase chain reaction. Multiple logistic regression was used to estimate odds ratios and 95% confidence intervals. Results: The prevalence of tumors positive for HPV-16 DNA was 21 of 30 (70%). None of the samples were positive for HPV-18 DNA. Compared with participants with HPV-negative tumors, patients with HPV-positive tumors had significantly higher mean alveolar bone loss (3.90 mm vs 2.85 mm, P=.01). After adjustment for age at diagnosis, sex, race/ethnicity, alcohol use, smoking status, and number of missing teeth, every millimeter of alveolar bone loss was associated with an approximately 4-fold (odds ratio,3.96; 95% confidence interval, 1.18-13.36) increased risk of HPV-positive tumor status. Number of missing teeth was not associated with tumor HPV status (odds ratio, 0.95; 95% confidence interval, 0.74-1.21). Conclusions: Chronic periodontitis may be a significant factor in the natural history of HPV infection in patients with base of tongue cancers. Additional confirmation in larger studies is required.