Oral HPV infection, HPV-related cancers more common in men
Oral HPV infection is more common among men than women, explaining why men are more prone than women to develop an HPV related head and neck cancer, according to a study presented at the Multidisciplinary Head and Neck Cancer Symposium.
Human papillomavirus, or HPV, has recently been linked to some types of head and neck cancer that are becoming more prominent in the United States, mostly among men. Patients infected with oral HPV type 16 have a 14 times greater risk of developing one of these cancers, which usually form on the tonsils and at the back of the tongue.
The correlation between HPV and oral cancer was only established in 2007, so it is not well understood how to detect or prevent these cancers.
Researchers sought to understand how prevalent oral HPV is in the U.S. and to understand the factors associated with infection. Data was collected from 5,579 men and women who participated in the National Health and Nutrition Examination Survey conducted by the U.S. Centers for Disease Control and Prevention between 2009 and 2010. It was found that 7 percent of the U.S. population between ages 14 and 69 had an oral HPV infection, with the infection being three times more common in men than women, 10.1 percent vs. 3.6 percent, respectively.
In the first study to examine the prevalence of oral HPV infection nationwide, rates of infection among men were about three times higher than among women.
Men are also three times more likely than women to develop head and neck cancers caused by HPV, says oncologist and researcher Maura L. Gillison, MD, PhD, of Ohio State University.
Gillison and colleagues estimate that about 7% of adults in the U.S. are infected with oral HPV and that the most prevalent type of the virus associated with oral infection is HPV-16 - the same sexually transmitted viral strain that causes a significant percentage of cervical cancers.
The study was published online today in the Journal of the American Medical Association to coincide with its presentation at the Multidisciplinary Head and Neck Cancer Symposium in Phoenix, Ariz.
“By 2020, there will be more HPV-positive oral cancers among men than cervical cancers among women in the U.S., and right now we don’t even have a way to screen for them,” Gillison says.
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By Salynn Boyles
Journal of the American Medical Association
About 1 percent of the population had an HPV 16 infection, with it being five times more common in men than women, correlating with the higher incidence of HPV-related cancer in men than women. Researchers do not yet know why the infection is more common in men than women in the first place.
The Role of Oral Sex
How does a sexually transmitted virus end up associated with cancers located so far away from the genitals? The answer is probably oral sex. Several studies have shown a relationship between oral sex and the presence of HPV DNA in mouth and throat samples. Other studies have shown a relationship between oral sex and HPV positive throat cancers, particularly in those individuals who perform oral sex on men.
Taken as a group, these studies are yet another chilling reminder that oral sex is not safer sex. Various other sexually transmitted diseases can be spread by oral sex including herpes, gonorrhea, chlamydia, and syphilis. Safer sex techniques should therefore be used for oral sex as well as vaginal and anal sex. This is particularly true for individuals with genital herpes or HIV infections, since both viruses have been shown to predispose people to acquiring HPV.
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By Elizabeth Boskey, Ph.D.
Two types of genital tract HPV in particular, HPV 16 and HPV 18, are known to cause the vast majority of cervical cancers, and new studies show that one of them, HPV16, is also linked to oral cancer as well. In the oral environment HPV16 manifests itself primarily in the back (posterior) regions such as the base of the tongue, the oropharynx (the back of the throat in the mouth), the tonsils and the tonsillar pillars. These oncogenic or cancer causing versions of HPV are also responsible for other squamous cell carcinomas, particularly of the anus and penis.
It has now been established that the path that brings people to oral cancer contains at least two distinct etiologies; one through tobacco and alcohol, and another via the HPV virus, particularly version 16, though other versions of the virus might be implicated as the research unravels further, though any others identified as of today are considered research data artifacts and not actual causative agents. The anatomical malignancy sites associated with each pathway appear to also be different from each other. In the broadest terms they can be differentiated into these areas; HPV related cancers appear to occur on the tonsillar area, the base of the tongue and the oropharynx, and non-HPV positive tumors tend to involve the anterior tongue, floor of the mouth, the mucosa that covers the inside of the cheeks and alveolar ridges (the ridge area in which the teeth reside). The data on these two distinct etiologies is coming out of researchers more rapidly now, and there are further definitions that seem to be apparent between the two. While these issues are discussed more fully in the PDF readable research articles included in this portion of the web site, in general it appears that HPV positive tumors occur most frequently in a younger group of individuals than tobacco related malignancies.