Oropharyngeal Cancer Epidemic and HPV | CDC EID

EID Journal Home > Volume 16, Number 11–November 2010
Volume 16, Number 11–November 2010
Synopsis
Oropharyngeal Cancer Epidemic and Human Papillomavirus

Torbjörn Ramqvist and Tina Dalianis Comments to Author
Author affiliations: Karolinska Institutet, Stockholm, Sweden (T. Ramqvist, T. Dalianis); and Swedish Institute for Infectious Disease Control, Solna, Sweden (T. Dalianis)

Suggested citation for this article

Abstract
A growing body of research shows that human papillomavirus (HPV) is a common and increasing cause of oropharyngeal squamous cell carcinoma (OSCC). Thus, the International Agency for Research against Cancer has acknowledged HPV as a risk factor for OSCC, in addition to smoking and alcohol consumption. Recently, in Finland, the United Kingdom, the Netherlands, the United States, and Sweden, incidence of OSCC has increased, and an increase in the proportion of HPV-positive tumors was noted. On the basis of these data and reports indicating that patients with HPV-positive cancer have their first sexual experience at a young age and have multiple partners, we postulate that increased incidence of OSCC in the United States and some countries in northern Europe is because of a new, primarily sexually transmitted HPV epidemic. We also suggest that individualized treatment modalities and preventive vaccination should be further explored.

In many countries, vaccines against some human papillomavirus (HPV) types are now administered to girls and young women with the goal of protecting them against HPV-induced cervical cancer (1,2). The introduction of HPV vaccines has also drawn more attention to the fact that HPV is associated not only with cervical cancer and genital warts but also with other tumors, such as head neck and anogenital cancers (3). We focus on the role of HPV in the increased incidence of oropharyngeal squamous cell carcinoma (OSCC), the head and neck cancer in which HPV is most commonly found (4).

Head and neck cancer most commonly is of the squamous cell carcinoma type (HNSCC) and includes cancers of the oral cavity, oropharynx, hypopharynx, larynx, sinonasal tract, and nasopharynx. HNSCC is the sixth most common type of cancer in the world; almost 600,000 cases are reported annually, and of these, ≈10% (or more for some geographic locations) are OSCC (5). Globally, the incidence and localization of HNSCC varies widely. It is the most common form of cancer in India, and incidence is higher in countries in Latin America than in the United States and northern Europe. In addition, men are generally more often affected than women. Smoking, alcohol consumption, and betel chewing are traditional risk factors for HNSCC and OSCC (6). However, during the past decade several reports have documented HPV in OSCC (7–9). HPV infection, with dominance of HPV16 infection, has therefore been acknowledged by the International Agency for Research against Cancer as a risk factor for OSCC (10). Moreover, there are accumulating reports from many countries that the incidence of OSCC is increasing. We suggest that this increase is caused by a slow epidemic of HPV infection–induced OSCC.


OSCC

Tonsillar cancer is the most common OSCC, followed by base of tongue cancer. Together, these 2 cancers account for 90% of all OSCCs (6,9). Patients usually do not seek counseling until the tumors are large because small tumors cause little distress and may not be noticed by the patient. Curative treatment implies surgery, radiotherapy, and chemotherapy; the goal is to cause as little functional and cosmetic damage as possible (6,9). If a cure cannot be obtained, palliative therapy is given to treat pain and discomfort. Similar to HNSCC, in general, survival rates for patients with OSCC are poor. Patients with OSCC have an overall 5-year survival rate of ≈25% (6,9). Furthermore, even when standardized treatment is used and tumors are at the same stage and have similar histologic features, it is difficult to predict the outcome. Several reports now describe the incidence of OSCC as increasing and indicate that HPV-positive OSCC has a better clinical outcome than HPV-negative OSCC (7–9,11–19). Thus, predictive and prognostic markers would be of clinical value for prevention and treatment of OSCC.

HPV

There are >100 HPV types, some found in skin warts and others in mucous tissues, and the association of different HPV types with cervical, some anogenital, and head and neck cancers is well established (3). The 8-kb, double-stranded, circular DNA HPV genome, enclosed in a 52–55 nm viral capsid, codes for the L1 and L2 viral capsid proteins and for the E1–E2 and E4–E7 proteins, which play major roles in gene regulation, replication, pathogenesis, and transformation (3). In high-risk HPVs (i.e., those that are more likely to cause lesions that may develop into cancer [www.cancer.gov/cancertopics/factsheet/Risk/HPV]), E6 and E7 deregulate cell cycle control by E6 binding and degradation of p53, and E7 binds and inhibits the function of the retinoblastoma protein (Rb) (3). The L1 protein can self-assemble into virus-like particles, which form the basis of both currently approved vaccines against HPV infection (1–3).

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Oropharyngeal Cancer Epidemic and HPV | CDC EID

Suggested Citation for this Article

Ramqvist T, Dalianis T. Oropharyngeal cancer epidemic and human papillomavirus. Emerg Infect Dis [serial on the Internet]. 2010 Nov [date cited]. http://www.cdc.gov/EID/content/16/11/1671.htm

DOI: 10.3201/eid1611.100452