Epidemiology of HPV-Associated Oropharyngeal Squamous Cell Carcinoma

Abstract

Oropharyngeal squamous cell carcinoma (OPSCC) arises from squamous epithelial cells that line mucosal surfaces in the oropharynx. This region includes the middle segment of the pharynx, that is, the base of the tongue, soft palate, tonsils, and side and back walls of the throat. The majority of OPSCC cases (~62 %) in the United States are caused by human papillomavirus (HPV), which is the most common sexually transmitted infection worldwide. HPV not only causes OPSCC, but cervical, vaginal, vulvar, anal, penile, and laryngeal cancers, genital warts, and respiratory papillomas. There is no cure for HPV, although prophylactic vaccination is available, safe, and highly effective if the three injection series is completed prior to infection. As a result of widespread vaccination of both males and females, the frequency of HPV-induced tumors is expected to decrease significantly. However, in the United States, HPV vaccination is not widespread; only ~57 % of girls ages 13–17 and ~35 % of teen boys have been vaccinated with at least one injection. In developing countries, such as Rwanda with government-implemented, school-based HPV vaccination, three-dose vaccination completion rates exceed 90 %. This chapter reviews the biology, prevalence, and transmission of HPV infection, the incidence, risk factors for and features of HPV-associated OPSCC, and strategies for preventing HPV infection and HPV-associated cancers.