Oral HPV infection is on the rise—and so are oropharyngeal cancers

The incidence of oropharyngeal squamous cell carcinoma
related to infection with human papillomavirus increased
225% over 16 years—and the number of cases is expected
to surpass the number of invasive cervical cancers in a few years

Senior Editor

The overall prevalence of oral human papillomavirus (HPV) infection in the United States is approximately 7% among men and women 14 to 69 years old, according to a study published January 26 in JAMA.¹ The prevalence is higher among men (10.1%) than women (3.6%).

Oral HPV is the cause of a subset of oropharyngeal squamous cell carcinomas (OSCCs). Ninety percent or more of HPV-positive OSCCs are caused by HPV 16. Oral HPV infection increases the risk of HPV-positive OSCC by a factor of approximately 50, the authors of the JAMA study note.

Although the incidence of HPV-negative OSCC decreased 50% from 1988 to 2004 in the United States, from 2.0 cases to 1 case for every 100,000 people, the incidence of HPV-positive OSCCs increased 225% over the same period, from 0.8 to 2.6 cases for every 100,000 people. Most of the increase was seen among young people, men, and people of white race.

“The increase among the young is consistent with reported sexual behavioral changes by birth cohort since the 1950s in the United States,” the authors write. “However, the reasons for the predominant increase among men are unclear.”

Details of the study

Gillison and colleagues from Ohio State University Comprehensive Cancer Center in Columbus, Ohio, analyzed data from a cross-sectional investigation performed as part of the National Health and Nutrition Examination Survey (NHANES) 2009–2010, a statistically representative sample of the US population. Participants (n = 5,579) provided a 30-second oral rinse and gargle with mouthwash. For detection of HPV types, DNA purified from oral exfoliated cells was evaluated.

Overall prevalence of oral HPV was 6.9% (95% confidence interval [CI], 5.7%–8.3%), and the most prevalent HPV type detected was HPV 16 (1.0%; 95% CI, 0.7%–1.3%).

Prevalence of oral HPV peaked in two age ranges:

• men and women 30 to 34 years old (7.3%; 95% CI, 4.6%–11.4%)

• men and women 60 to 64 years old (11.4%; 95% CI, 8.5%–15.1%).

Prevalence was higher among current smokers and heavy alcohol users and among former and current marijuana users. The association between smoking and oral HPV infection was stronger among women than men.

Prevalence was also associated with several measures of sexual behavior. For example, it was higher among people who reported ever having sex versus those who never had (7.5% vs. 0.9%). Prevalence increased with lifetime or recent number of partners for any kind of sex, vaginal sex, or oral sex. One in every five people who reported more than 20 lifetime sexual partners was infected.

“Our data provide evidence that oral HPV infection is predominantly sexually transmitted,” the authors write. “Infection was uncommon among sexually inexperienced individuals, and was 8-fold higher among sexually experienced individuals, and increased significantly with number of sexual partners.”

Vaccine’s effects on oropharyngeal cancers is unknown

The US Centers for Disease Control and Prevention recommends HPV vaccination for females 9 to 26 years old to prevent cervical and anogenital cancers and genital warts. It also recommends vaccination for males 9 to 21 years old to prevent anogenital cancers and genital warts. The efficacy of the HPV vaccine against oral HPV infection is unknown, however.

Gillison and colleagues note a recent analysis of US cancer registry data, which projected that the number of HPV-positive oropharyngeal cancers will surpass that of invasive cervical cancers by the year 2020.²

As a result, they recommend vaccine trials to determine “the benefits of HPV vaccination for males, given the higher prevalence of oral HPV infection demonstrated here as well as higher incidence of HPV-positive OSCC among men.”¹

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