Single Men: Higher Risk of Cancer-Linked Oral HPV?
But overall risk is low, and virus usually clears within a year, study found
By Amy Norton
TUESDAY, July 23 (HealthDay News) -- It's rare for men to contract an oral HPV infection, but single men and smokers face a relatively greater risk, a new study suggests.
The study, published online recently in The Lancet, followed more than 1,600 men to chart rates of oral infection with HPV, or human papillomavirus. HPV, which can cause genital and anal warts, is the most commonly transmitted sexual infection in the United States. Some strains of the virus can eventually lead to cancer.
But it has not been fully clear how often HPV infects the mouth and throat. The answer, at least in healthy men, is not very often, based on the new findings.
However, being single or being a smoker were risk factors for initial infection. Smokers had nearly three times the risk of a cancer-linked HPV infection, versus nonsmokers. Singles were about three to four times more likely to contract a cancer-linked infection than men who were married or living with someone.
Overall, less than 2 percent of the study participants contracted an HPV strain linked to an increased cancer risk in one year. And for most men, the immune system cleared the virus within a year.
The findings are "reassuring," partly because it's persistent infections that present a cancer risk, said Dr. Edgar Simard, a researcher with the American Cancer Society who was not involved in the work.
Cervical cancer is the best-known HPV-linked cancer. But HPV infections of the mouth and throat can promote oropharyngeal cancer -- which affects the back of the throat, base of the tongue and tonsils.
It's a rare cancer, but the number of cases tied to HPV is on the rise in the United States. No one knows why, Simard said.
HPV-linked throat cancer recently came to the public's attention when the British newspaper The Guardian reported that actor Michael Douglas' recent bout with the disease might have been caused by oral sex. Douglas is also a longtime smoker.
To figure out how to prevent HPV-linked oropharyngeal cancer, "we need to improve our understanding of the risks associated with oral HPV infection and persistence," said researcher Christine Pierce Campbell, a postdoctoral fellow at the Moffitt Cancer Center in Tampa, Fla.
The reasons aren't clear, according to Pierce Campbell. But she speculated that single men tend to have riskier sexual behaviors. As for smoking, it's possible that inflammation in the oral cavity, and a dampened immune system, make people more vulnerable to an HPV infection.
"That's a plausible explanation," Simard agreed. "It makes sense biologically." He added, though, that smokers may also just happen to have different sexual practices than nonsmokers. "Is smoking a proxy for some risky sexual behavior?" he said.