Human Papillomavirus and Oropharyngeal Squamous Cell Carcinoma of the Head and Neck: A Growing Epidemic

Abstract

Human papillomavirus (HPV) is now considered a major causative agent in oropharyngeal squamous cell carcinoma (OP-SCC). The incidence of HPV+ OP-SCC is increasing dramatically, is higher in men, and is now more common than cervical cancer in the United States. HPV+ OPSCCs usually present as locally advanced, stage IV cancers, requiring intensive treatment with surgery, chemotherapy, and/or radiation that can cause tremendous morbidity. HPV vaccination is predicted to prevent HPV+ OP-SCC because over 90% are caused by vaccine-type HPV. However, current vaccination rates are not yet high enough to be effective at preventing HPV-associated malignancies at a population level.

Figure 1

Anatomic depiction of the oropharynx. Source: Centers for Disease Control and Prevention. The HPV-Associated Cancers page. Available at: http://www.cdc.gov/cancer/hpv/basic_info/cancers.htm. Accessed January 31, 2014.

Figure 2

Schematic depiction of tonsillar epithelium. (a) Topography of the human palantine tonsil. The surface epithelium of the palatine tonsil deeply invaginates into a lymphoid stroma as blind-ending and ramifying crypts (boxed area) that increase the surface area of the tonsil by nearly 700%. Drawing by Max Brödel. (b) The specialized reticulated epithelium lining the tonsillar crypts. The zones of squamous epithelium—the basal, intermediate, and superficial layers—are interrupted by migrating nonepithelial cells including lymphocytes and antigen-presenting cells. Loss of structural integrity leaves the basement membrane exposed to deposition of viral particles. Drawing by T. Phelps. Abbreviations: APG: antigen presenting group; HPV, human papillomavirus. Source: Pai SI, Westra WH: Molecular pathology of head and neck cancer: implications for diagnosis, prognosis, and treatment. Annu Rev Pathol 4:49-70, 2009.