Men Are More Likely to Have Oral HPV than Women
A rise in oral sex may be pushing up HPV infection rates in
men, along with head and neck cancers caused by the virus.
By Alice Park January 27, 2012,
infections of human papillomavirus, or HPV, affect nearly 7% of Americans
and are significantly more common in men than in women, according to a new
Centers for Disease Control and Prevention study.
The study, which is the first to examine the prevalence of oral HPV in the
U.S., found that three times as many men (10%) as women (3.6%) have HPV
infections. The data may help to explain why the incidence of head and neck
cancers has been increasing, particularly in males, even as smoking rates
are on the decline.
For the study, CDC researchers plumbed data on 5,579 people aged 14 to 69
who participated in the National Health and Nutrition Examination Survey in
2009 and 2010. The participants answered extensive questionnaires about
their sexual behavior and gave oral cell samples for analysis for HPV.
The researchers found that the risk of oral HPV infection increased with the
number of sexual partners a person had: it was eight times higher in people
who had ever had sex versus not, and as high as 20% in people who had had
more than 20 sexual partners in their lifetime. The data indicate that ďoral
HPV infection is predominantly sexually transmitted,Ē through oral sex, not
passed through casual contact like kissing, the authors concluded.
The CDC researchers also found that HPV infections peaked in two age groups:
30-to-34-year-olds, who had a 7.3% chance of infection, and
60-to-64-year-olds, who were 11.4% likely to be infected. Itís not clear why
older people had higher rates of oral HPV, but the authors offered some
possible theories: perhaps itís because older people came of age at a time
when there were fewer concerns about sexually transmitted infections, or
perhaps latent HPV infections are becoming reactivated as the immune system
weakens with age.
HPV is the most commonly sexually transmitted virus in the U.S. At least
half of all sexually active people will acquire an infection at some point
in their lives. Most will clear the virus on their own, but persistent
infections can cause cancer, including cervical, vulvar, vaginal, anal and
penile cancers. Oral infection with a high-risk strain of HPV can cause
oropharyngeal cancers ó cancers of the tonsils, upper throat and base of the
Rates of oral HPV infection are substantially lower than genital infections
ó which can be as high as 42% in women in their 20s, for example ó but they
are becoming increasingly troublesome. While HPV is best known as the virus
that causes cervical cancer in women, because of better screening, the rate
of such cancers has declined. Meanwhile, the rate of oral cancers is on the
rise: a study published in October in the Journal of Clinical Oncology found that
HPV-related oropharyngeal cancers increased 225% between 1984-89 and
2000-04. In 1984-89, about 16% of oropharyngeal cancers tested HPV-positive;
by 2000-04, the proportion of HPV-positive cancers had risen to 72%,
accounting for more oral cancer than smoking.
Overall, the risk was greatest and rising in men, the study found, possibly
because of increasing rates of oral sex. The data indicate that the burden
of HPV-related cancer may shift from women to men, with the number of HPV-positive
oral cancers potentially eclipsing that of invasive cervical cancers within
That supports efforts to boost HPV vaccination, suggest the authors of the
current CDC study, published
online by the Journal of the American Medical Association.
Public health officials recommend that
girls aged 11 or 12 be immunized with either of two approved HPV vaccines,
Gardasil or Cervarix, which both protect against HPV 16 and 18, the strains
that cause most cervical cancers. (Gardasil also protects against HPV
strains 6 and 11, which cause 90% of genital warts cases.) Girls aged 13 to
26 should also be immunized if they havenít been already.
extends to boys as well, but only one of the shots, Gardasil, has
been tested and approved for males to protect against warts and anal cancer.
Boys are advised to receive the vaccine at age 11 or 12, or between ages 13
and 21 if they havenít already been immunized. The primary reason for the
advice is to protect adolescents and young adults from infection with the
high-risk strains of cancer-causing HPV before they become sexually active.
Itís not clear whether the vaccines can also protect against oral cancers.
More research is needed to figure that out. But researchers speculate that
if the vaccine reduces rates of HPV in women, it can in turn help reduce the
risk of infection in men.
Read more: http://healthland.time.com/2012/01/27/men-are-more-likely-to-have-oral-hpv-than-women/?xid=newsletter-healthland#ixzz1khfUTaXl