The role of chronic periodontitis in prevention and treatment of head and neck cancers

Morbidity and mortality from head and neck squamous cell carcinoma (HNSCC) are high and this has not improved in decades in spite of extensive research. Additional approaches are necessary to change this status quo. Chronic infection and inflammation have been linked to carcinogenesis in few organs. Periodontitis is a chronic oral infection caused by inflammatory reactions in response to gram negative anaerobic bacteria in the endogenous dental plaque. It leads to irreversible destruction of tissues around teeth clinically detectable as periodontal pockets and alveolar bone loss. Periodontal pockets were also suggested as reservoirs for human papillomavirus (HPV). Chronic proliferation and ulceration of the pocket epithelium may help HPV’s acquisition and persistence. The results from our NIH-funded study suggest a robust independent association between the history of periodontitis and incident HNSCC. Analyses from a small subset of this population also suggest a synergy between periodontitis and oral HPV infection. This review will summarize the evidence supporting: 1) the association between chronic periodontitis and HNSCC, 2) HPV-periodontitis synergy, 3) the biological mechanisms behind these two associations, and 4) implications for safe and practical treatment strategies for HNSCC.