Oral HPV infection common among US men

Gillison ML. JAMA. 2012;307:doi:10.1001/jama.2012.101.

Issue: March 2012

The rate for oral human papillomavirus infection was nearly threefold among men than women in the United States, according to Maura L. Gillison, MD, PhD.

“Oral HPV infection is the cause of the cancer [oropharyngeal squamous cell carcinoma] rising in incidence largely among men in the United States, and yet, very little is known about oral HPV infection,” Gillison, of the Ohio State University Comprehensive Cancer Center, told Infectious Disease News.

For this reason, Gillison and colleagues aimed to assess the prevalence of oral HPV infection among 5,579 men and women aged 14 to 69 years included in National Health and Nutrition Examination Survey from 2009 to 2010. Study participants provided a 30-second oral rinse and gargle sample with mouthwash. The researchers examined DNA purified from oral exfoliated cells using polymerase chain reaction (PCR) and type-specific hybridization.

Overall, the prevalence of oral HPV infection among men and women was 6.9% (95% CI, 5.7-8.3). However, compared with women, men had a significantly higher prevalence for any oral HPV infection (10.1%; 95% CI, 8.3- 12.3) vs. (3.6%; 95% CI, 2.6-5.0), according to the study.

HPV infection was highest among men aged 30 to 34 years (7.3%; 95% CI, 4.6-11.4) and 60 to 64 years (11.4%; 95% CI, 8.5-15.1). The rate increased with an increased number of sexual partners (P<.001) and cigarettes smoked per day (P<.001).

“Similar studies of cervical HPV infection among women, ultimately, led to the development of very important public health interventions, such as HPV vaccination to prevent cervical HPV infection, as well as HPV detection to screen for cervical cancer,” Gillison said. “Oropharynx cancers, by contrast, have no analogous screening methodology. It is hoped that additional research on oral HPV infections stimulated by these findings will result in similar health interventions for oropharynx cancer.”

In an accompanying editorial, Hans P. Schlecht, MD, of Drexel University College of Medicine in Philadelphia, said: “Future research will need to identify the natural history of HPV-related oropharyngeal dysplastic lesions and evaluate potential screening methods to detect oropharyngeal dysplasia prior to invasion. Successful screening measures such as a Papanicolaou test, HPV PCR testing, or both may be daunting to achieve, but there is meaningful hope that prevention efforts will ameliorate the effects of HPV-related oropharyngeal cancer.”

Disclosure: This research was supported by the Ohio State University Comprehensive Cancer Center, Merck, John and Nina Cassils and the Intramural Research Program of the NCI.

Seventy years ago, Dr. George Papanicolaou described a screening test for cervical cancer, and thirty years ago, Dr. Harald zur Hausen discovered that HPV was the causative agent of cervical cancer. Approximately one of six cancers has an underlying infection as an etiology. The further work has shown that HPV infection is linked to several ano-genital cancers, including vulvar, vaginal and anal cancers.HPV is a large family of viruses and HPV 16 is the type most associated with human cancers.

A growing body of evidence has linked cancers in the head and neck region to HPV infections and at some sites a majority of these squamous cell carcinomas may be positive for HPV 16. This recent study by Gillison and colleagues looked at the cross sectional prevalence of HPV infections of the oral cavity in the latest NHANES data. The overall prevalence was 7%. Prevalent oral HPV infections were linked with sexual behaviors such as number or partners and vaginal/oral sex.

Multiple similar studies have been done concerning genital tract infections with HPV, including one using the NHANES data that was published in JAMA. These studies have consistently linked sexual behavior to prevalent HPV infection. What is missing concerning the HPV/oral cavity story is longitudinal studies. A majority of sexually active women will acquire an HPV infection in the genital tract, and we do not know if this is true for the oral cavity. Another unknown is whether the currently marketed HPV vaccines will prevent oral cavity infection with HPV. HPV vaccination is highly effective at preventing HPV infection of the epithelium of the cervix, vagina, vulva, penis and anus. Both versions of the HPV vaccine protect against HPV 16 infections, and HPV 16 is the most commonly found HPV type in the oral cavity and the HPV type most closely associated with head and neck cancers.

Also, we do not know if there is a pre-malignant state in the oral cavity analogous to cervical dysplasia. The success of the “Pap” smear has been to identify cervical dysplasia when it is easily treated and has not progressed to invasive disease. To prevent head and neck cancers, we will need further research concerning the natural history, diagnosis and treatment of these infection related cancers. Primary prevention of these HPV related cancers may also be an achievable goal. The study by Gillison and colleagues has been widely reported in the lay press, and hopefully, will prompt an increase in our country’s very low HPV vaccine coverage rates.

- Kevin A. Ault, MD

Emory University School of Medicine

Disclosure: Dr. Ault reports no relevant financial disclosures.

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