Infections Related to Development of Head and Neck Cancers

Worldwide, over 550,000 new cases of head and neck cancer are diagnosed each year. Of those, approximately 119,000 are diagnosed in the United States. Head and neck cancers are predominately squamous cell carcinoma of the tongue, pharynx and larynx but they can also be other types of cancers that arise within the nasal cavity, sinuses, lips, mouth, thyroid gland, skin, salivary glands and ears. These cancers often present at an advanced stage (III or IV) and require multimodal therapy with a combination of surgery, radiation and/or chemotherapy. Alcohol and smoking are established risk factors for these cancers that increase risk independently (with tobacco exposure conveying a higher risk) and synergistically. Other important causes of head and neck cancers are infectious microbes, including but not limited to human papilloma virus (HPV), Epstein-Barr virus (EBV), and Merkel Cell Polyomavirus. The majority of this chapter will cover HPV and its implication for the development of head and neck squamous cell carcinoma (SCC), especially within the oropharynx.