Male
Circumcision May Decrease Risk Of HPV
Infection And Cervical Cancer ScienceDaily
(Dec. 20, 2008) — Two new studies suggest that male
circumcision may assist in
the prevention of human papillomavirus (HPV) infection,
particularly infection with the high-risk
subtypes associated with cervical, penile,
and other cancers.
Both studies are published in the January 1 issue of
The Journal of Infectious Diseases, now
available online.
High-risk subtypes of HPV have been estimated to be
present in 99.7 percent of cervical
cancers worldwide. Evidence has shown that women with circumcised partners have a reduced
risk for genital cancer. Two new studies sought to
discover if HPV infection is more likely to
occur in uncircumcised compared with
circumcised men.
Bertran Auvert MD, PhD, and his team of researchers
in France and colleagues from South
Africa studied data from a trial conducted in Orange Farm,
South Africa. Uncircumcised men
aged 18-24 years were randomized into either an intervention group, to be circumcised, or a
control group, to remain
uncircumcised. During this study, urethral swab samples were
collected and analyzed for
presence of HPV among men followed up for 21 months.
Information about sexual
behavior was also collected.
Dr. Auvert and colleagues found that the percentage
of high-risk HPV genotypes was lower in
the circumcised group than in the control group. The most
important implication, according to
researchers, was that “reducing the frequency of HPV infection among men will reduce the risk
of exposure in their female
sexual partners.”
A second study by Carrie Nielson PhD, at the Oregon
Health & Science University and
colleagues at the University of Arizona, H. Lee Moffitt Cancer Center
and Research Institute,
and the Centers for Disease Control and Prevention
tested more than four hundred men aged
18-40 years in two U.S. cities during
2002-2005. Sixteen percent of participants were
uncircumcised. Researchers tested for HPV in skin swabs of the anogenital area and semen
samples in participants with
no HPV symptoms (such as warts or lesions).
Investigators found that circumcised men were about
half as likely to have HPV as
uncircumcised men, after adjustment for other differences in the two
groups. These results
demonstrated that lack of circumcision is associated with cervical
cancer because of the
increased risk of HPV infection. Nielson suggested that it
may be useful to consider
circumcising newborn boys in order to decrease the risk
of HPV infection for them and their
future partners. “Parents are not currently
advised of this risk,” she said. “These studies
contribute to the evidence that might help
to inform that decision.”
In an accompanying editorial, Ronald H. Gray, MD, of
Johns Hopkins University, said that the
evidence was persuasive but not entirely consistent and that
it may be premature to promote
circumcision as a way to prevent HPV infection in men
and to protect female sex partners from
infection. He advised that policy
decisions should await results from two ongoing trials of male
circumcision.
Alternatively, Gray noted that consistent evidence has suggested that male
circumcision
reduces the frequency of HIV infection in men. He also pointed out that because
of the lack of conclusive data relating circumcision and prevention of HPV, Medicaid
does not
cover circumcision costs, which may account for a decline in neonatal
circumcisions in the
United States.
According to Dr. Nielson, the findings they reported
present compelling arguments to promote
male circumcision in developing countries where circumcision is
not widely used and the HIV
epidemic is severe. Additionally, she said, it is
“the first clear demonstration of the indirect but
substantial beneficial effect of
male circumcision for women.” The authors of both studies and
the editorialist
agreed that more studies will be needed to confirm the efficacy of male
circumcision in
HPV prevention.
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