HealthDay News — U.S. incidence of oropharyngeal squamous-cell carcinoma (OSCC) caused by human papillomavirus has increased from 0.8 per 100,000 to 2.6 per 100,000 from 1988 to 2004, yet health officials knew little about the epidemiology of oral HPV infection until now.

Maura L. Gillison, MD, PhD, from the Ohio State University Comprehensive Cancer Center in Columbus, and colleagues examined data from National Health and Nutrition Examination Survey 2009-2010 participants, to determine oral HPV prevalence and identify potentially modifiable risk factors.They extracted DNA from the oral exfoliated cells of 5,579 participants, aged 14 to 69 years.

Oral HPV infection was identified in 6.9% using polymerase chain reaction assay and hybridization genotyping, with high-risk HPV-16 most prevalent, accounting for 1% of all infections, Gillison and colleagues reported online in the Journal of the American Medical Association

Continue Reading

Age and gender were associated with oral HPV prevalence, with infection rates peaking between the ages of 30 and 34 years and again at ages 60 to 64 years. Oral HPV prevalence was approximately threefold higher in men than women (10.1% vs 3.6%, P < .001), with men demonstrating a more than fivefold higher prevalence of HPV-16 than women (1.6% vs 0.3%, P < .001). 

These results are consistent with higher rates of HPV-positive OSCC among individuals aged 50 to 64 years and among men, the researchers noted. 

Additionally, participants with a history of sexual contact were more likely to have oral HPV infection than those who had never had sexual contact (7.5% vs. 0.9%, P < .001), with oral HPV prevalence increasing significantly with the number of sexual partners for any kind of sex, vaginal sex or oral sex (all P < .001 for trend).These data provide evidence that oral HPV infection is predominantly sexually transmitted, the researchers wrote.

Current cigarette smoking intensity was independently associated with oral HPV prevalence, with incidence increasing with the number of cigarettes smoked per day (P = .001 for trend).

Oral HPV prevalence was as high as 20% among those with more than 20 lifetime sexual partners or among current smokers of more than 20 cigarettes per day, the researchers noted. 

“The oral HPV prevalence across age and sex observed in this study appears consistent with differences in incidence of HPV-positive OSCC across these subgroups, raising the question as to whether targeted secondary prevention strategies are feasible,” they wrote.

Although the CDC currently recommends routine HPV vaccination for females aged 9 to 26 years and males aged 9 to 21 years to prevent genital warts and anogenital cancers based on demonstrated efficacy in randomized clinical trials, further studies are needed to determine the vaccine’s efficacy against oropharyngeal cancer.

In an accompanying editorial, Hans P. Schlecht, MD, MMSc, wrote that it will be decades before health officials are able to detect decreases in oral HPV and associated OSCCs from vaccination efforts, and urged primary care health providers to encourage patients who engage in oral sex to use barrier protection.

“Physicians should also be vigilant for the signs and symptoms of oropharyngeal cancer, such as persistent odynophagia, dysphagia, dysphonia, otalgia, a feeling of globus, a neck mass, or unexplained weight loss, and perform a thorough head and neck evaluation if present,” Schlecht added.

One of the study authors disclosed financial ties to pharmaceutical companies, including Merck, which partially funded this study.

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

Schlecht HP. JAMA. 2012; doi:10.1001/jama.2012.117.