THURSDAY, Jan. 26, 2012 (HealthDay News) -- Almost 7 percent of American men and women are infected orally with the human papillomavirus (HPV), new research reveals, with men showing significantly higher infection rates than women.
In fact, the study found that among those between the ages of 14 and 69, men seem to face a nearly threefold greater risk than women for oral HPV infection.
The authors noted that the gender gap grows even wider with respect to HPV-16, a strain that is responsible for the vast majority of HPV-related cases of oral cancer. Men are five times more likely to be infected with HPV-16 than are women, the study found.
The biggest risk factors for oral HPV infection include sex and tobacco use, the researchers say.
"Our data link oral HPV infection to the number of sex partners and to smoking," said study author Dr. Maura Gillison, chair of cancer research in the department of viral oncology at Ohio State University's Comprehensive Cancer Center in Columbus.
"This suggests that people might reduce their risk of infection by limiting the number of sex partners and not smoking cigarettes," she added. "[However] at this point, we don't know if consistent use of condoms or other barrier methods for oral sex will reduce oral HPV transmission."
She added that smoking is thought to raise the odds of oral HPV infection via either its suppressive effects on the immune system or by damaging the mucosal lining of the mouth.
Gillison and her team report the findings in the Jan. 26 online issue of the Journal of the American Medical Association. They are also scheduled to present the results Thursday at the Multidisciplinary Head and Neck Cancer Symposium, in Phoenix.
The U.S. Centers for Disease Control and Prevention noted that genital HPV infection remains the most common form of the sexually transmitted disease. To lower the associated risk for developing cervical cancer, the CDC recommends that girls between the ages of 11 and 26 take advantage of current HPV vaccines.
However, the current finding comes on the heels of a report published in the Journal of Clinical Oncology last October that showed a dramatic two-decade rise in the incidence of oral cancers attributed to HPV infection.
To better understand that connection, Gillison's team sifted through data on nearly 5,600 men and women collected between 2009 and 2011 by the National Health and Nutrition Examination Survey (NHANES).
All NHANES participants had been examined in person, during which all were tested for HPV.
The researchers found an overall oral HPV infection rate of 6.9 percent, with HPV-16 being the most common type.
Oral HPV incidence varied with age, however, with peak rates occurring among those between the ages of 30 and 34 (at 7.3 percent) as well as among men and women between 60 and 64 (11.4 percent).
Overall, oral HPV infection hit the 10 percent mark among men. Among women it was just shy of 4 percent.
While those with a history of smoking, heavy drinking, and/or marijuana use appeared to face a higher risk for infection, sexual behavior also plays a key role in upping a person's risk.
For example, while those who had never had sex faced less than a 1 percent risk for oral HPV infection, prevalence hit 7.5 percent among those who were sexually active. And the greater the number of sexual partners, the higher the risk.
"[But] our findings are reassuring in one important sense," noted Gillison. "Although we found that infection is common, the cancer itself is rare, which tells us that the majority of people who have oral HPV infection do not get cancer."
Dr. Janice Dutcher, an oncologist at the Continuum Cancer Centers of St. Luke's Roosevelt Hospital Center in New York City, said the results ring true.
"I think that this is real," she said. "This is a virus that is clearly associated with cervical cancer as well as anal cancer. So the fact that there is also an association with oral cancer, and that the risk for transmission may be related to oral sex, is not surprising."
In that case, should current vaccination recommendations regarding girls and cervical cancer be broadened to include both girls and boys?
"Absolutely," said Dutcher. "It's pretty straightforward, frankly. Of course, if this were something that wasn't sexually transmitted it would be easier to accept. Given the taboos around sex in our society, it makes people very nervous. But clearly from a virological and medical perspective it makes perfect sense."
There's more on HPV at the U.S. Centers for Disease Control and Prevention.