Oropharyngeal carcinoma: A unique human papillomavirus-associated tumor of the head and neck

Head and neck squamous cell carcinoma (HNSCC) describes a group of tumors of mucosal origin that occur in the oral cavity, nasal cavity, paranasal sinuses, pharynx, and larynx. Head and neck squamous cell carcinoma is the sixth most common form of cancer worldwide, with more than 500,000 new cases diagnosed annually. Traditional established risk factors include consumption of tobacco and alcohol and substances known to contain DNA-damaging carcinogens. With the general decline in the use of tobacco in developed countries, there has been a concomitant reduction in the overall incidence of HNSCC. A notable exception has been the rapid increase in the incidence of HNSCC occurring in patients without the demographic features and risk factors traditionally associated with the disease. This increase is being seen in a population of patients, predominantly white men, who are relatively young and without a history of smoking and/or heavy alcohol consumption, which traditionally characterizes the HNSCC patient population. Sexually acquired oncogenic subtypes of human papillomavirus have recently been established as the etiological agents in this subgroup of patients. Human papillomavirus-associated carcinomas tend to arise in the oropharynx, and identification of human papillomavirus-associated tumors has significant therapeutic and prognostic implications. Thus, whereas HNSCC was previously thought to be a homogeneous disease, the striking heterogeneity of tumors in this site is becoming increasingly evident.