Men face higher risk of cancers linked to oral sex

For men, the risk of HPV-driven cancers of the head and
neck rise along with the number of oral sex partners,
researchers said Friday at the American Association for
the Advancement of Science (AAAS) annual meeting in
the US capital.
Nearly two out of three of these oral cancers in the
United States and most western nations are caused by
infection with the HPV 16 strain of the virus, and
incidence of cancer is on the rise in recent years, said
Gypsyamber D'Souza, who teaches epidemiology at
Johns Hopkins University in Baltimore, Maryland.
Middle aged white men are at particularly high risk
compared to other races.
She said her research shows that youths are engaging in
oral sex at increasingly young ages, compared to past
generations.
"Our research shows that for men, the number of oral sex
partners -- as that number increases, the risk of an oral
HPV infection increases," she told reporters.
But with women, the number of sexual partners does not
appear to raise the risk.
"Comparing men and women with the same number of
sexual partners, a man is much more likely to become
infected with oral HPV than a woman."
Furthermore, women who have a greater number of
vaginal sex partners appear to face a lower risk of oral
HPV infection, she said.
The reason may be that when women are first exposed to
HPV vaginally, they mount an immune response that
prevents them from getting an oral HPV infection, she
said.
But men do not seem to have equally robust immune
responses.
"Men are not only more likely to be infected with oral HPV
infection than women, but our research shows that once
you become infected, men are less likely to clear this
infection than women, further contributing for the cancer
risk."
HPV infection is quite common, and most people clear
the virus within a year or two, she said.
In some cases, however, HPV does not go away and can
lead to cellular changes in the mouth and throat, which
eventually become cancerous.
Oral sex may raise the risk of head and neck cancer by
22 percent, according to a study published January in the
Journal of the American Medical Association (JAMA).
This type of cancer has risen 225 percent in the last two
decades.
The US Centers for Disease Control and Prevention (CDC)
urges HPV vaccination for all pre-teen boys and girls so
they can be protected against the infection before they
become sexually active.