Approximately 7% of Americans carry the human papillomavirus (HPV) in their oral cavities, and men are 3 times more likely to carry the virus than women.
New findings from a prevalence study of HPV infection were presented Thursday at the Multidisciplinary Head and Neck Symposium in Phoenix, Arizona, and was concurrently released in the Journal of the American Medical Association
The cross-sectional study was based on samples taken from 5579 men and women between the ages of 14 to 69 years that were obtained at mobile examination centers as part of the National Health and Nutrition Examination Survey (NHANES). The samples were obtained through an oral rinse, and subsequent DNA samples were used to determine the HPV type. Each person also answered a questionnaire to obtain sociodemographic data and completed a computer-assisted self-interview about sexual history and substance abuse
The HPV prevalence throughout the study population was 6.9% (95% CI, 5.7%-8.5%). The prevalence of HPV type 16, the most common form (and one closely associated with the development of oropharyngeal cancer) was 1.0% (95% CI, 0.7%-1.3%). Among all HPV types, men had a higher prevalence of HPV (10.1% [95% CI, 8.3%-12.3%]) than women (3.6% [95% CI, 2.6%-5.0%, P
<.001]). Sexual contact was identified as a major factor in the rate of infection, with 7.5% of those who had experienced any form of sexual contact (95% CI, 6.1%-9.1%) exhibiting the virus, compared to 0.9% (95% CI, 0.4%-1.8%, P
<.001) who had not experienced any form of sexual contact.
“This study of oral HPV infection is the critical first step toward developing potential oropharyngeal cancer prevention strategies,” said Maura Gillison, MD, PhD, lead author of the study and the Jeg Coughlin Chair of Cancer Research at The Ohio State University in Columbus. “This is clearly important because HPV-positive oropharyngeal cancer is poised to overtake cervical cancer as the leading type of HPV-caused cancers in the US, and we currently do not have another means by which to prevent or detect these cancers early.”
Further analysis showed that some risk factors made people in the study population particularly susceptible to being infected by the virus. For example, the HPV prevalence in men and women who had more than 20 sexual partners in their lifetime was 20.5% (95% CI, 17.4%-23.9%). In those who smoked more than 20 cigarettes a day, the HPV prevalence was 20.7% (95% CI, 12.6%-32.0%).
While cigarette and alcohol use have classically been associated with the disease, Gillison said that this study suggests that oral HPV is predominantly sexually transmitted. Gillison and the other authors of the study suggest that factors such as sexual behavior (ie, transmission of HPV via oral sex on women vs men) and hormonal differences may affect the duration of infection, and may explain why men had a higher overall rate of HPV prevalence than women. The overall incidence of HPV-positive oropharynx cancers increased by 225% between 1988 and 2004, according to National Cancer Institute research. There were an estimated 6700 cases of HPV-positive oropharynx cancers in 2010, up from 4000 to 4500 in 2004.
Gillison said that the study was not necessarily designed to advocate the use of vaccines on boys and girls before they become sexually active. However, Gillison said that large, prospective studies on the effectiveness of HPV vaccinations should be the next step in determining whether or not the vaccinations should be made mandatory at a national level or global level.
“It’s difficult to make public policy recommendations based on a hope or a speculation,” Gillison said.