Oral human papillomavirus (HPV) infection is more common among men than women,
leading to an increased risk for men of head and neck cancers, a US study
suggests.
The Journal of the American Medical Association (JAMA) study assessed around
5,500 people aged 14 to 69.
Around 10% of men had oral HPV, compared with 3.6% of women.
HPV causes the majority of cervical cancers, as well as genital and anal - and
head and neck cancers.
Smoking and drinking are significant known risk factors for head and neck
cancers. But oral HPV infection increases cancer risk by around 50%, according
to the research team from Ohio State University Comprehensive Cancer Center.
They say the incidence of head and neck cancers has significantly increased
over the last three decades, and HPV has been directly implicated as an
underlying cause.
The researchers used data from a cross-sectional study as part of the 2009-10
National Health and Nutrition Examination Survey.
They all provided a skin cell samples for testing from their mouths, and were
interviewed about their lifestyles and sexual history.
Overall prevalence of oral HPV infection was 7%.
Prevalence of HPV increased with lifetime or recent number of partners for any
kind of sex, vaginal sex, or oral sex.
Writing in JAMA, the team led by Dr Maura Gillison, said their findings should
influence research into the existing HPV vaccines and how effective they could
be in preventing oral cancers.
"Vaccine efficacy against oral HPV infection is unknown, and therefore
vaccination cannot currently be recommended for the primary prevention of
oropharyngeal cancer.
"Given an analysis of US cancer registry data recently projected that the
number of HPV-positive oropharyngeal cancers diagnosed each year will surpass
that of invasive cervical cancers by the year 2020, perhaps such vaccine trials
are warranted."
Jessica Harris, health information manager at Cancer Research UK, said: "As we
learn how common HPV infections in the mouth are, and how they are passed on,
we can understand more about who is most at risk and how people can reduce the
risk of HPV-related cancers.
"Although there isn't yet any evidence to show whether HPV vaccination is
effective at preventing oral HPV infections, results like these are vital to
help inform prevention programmes in the future."