Technology & Science

Circumcision prevents HPV spread: study

Circumcision can help prevent men from transmitting the virus that causes cervical cancer to their female partners, a Ugandan study suggests.

Circumcision can help prevent men from transmitting the virus that causes cervical cancer to their female partners, a Ugandan study suggests.

Researchers in Uganda randomly assigned men to circumcision immediately as a treatment or after 24 months as a control, and their female partners were tracked for two years to look for infections with human papillomavirus, which can cause cervical cancer and genital warts.

After 24 months, 27.8 per cent of the steady partners of circumcised men had HPV infections, compared with 38.7 per cent of the partners of uncircumcised men, the study's authors reported in this week's issue of the medical journal The Lancet.

"Our findings indicate that male circumcision should now be accepted as an efficacious intervention for reducing the prevalence and incidence of HPV infections in the nearly 1,000 female partners. However, protection is only partial; the promotion of safe sex practices is also important," Dr. Maria Wawer and colleagues at Johns Hopkins University in Baltimore wrote.

The protection is only partial, since there are dozens of strains of HPV that are highly contagious. Most people who are infected clear the virus on their own, but it can cause changes that lead to cancer in some.

GlaxoSmithKline and Merck make vaccines against HPV but they are not available to most women in developing countries.

Since vaccination and circumcision offer only partial protection, practising safe sex is still paramount, the researchers cautioned.

Limits to vaccination

"Recent findings add important evidence for the promotion of male circumcision in countries without well-established programmes for cervical screening," Dr. Anna Giuliano of the department of cancer epidemiology and genetics at the H Lee Moffitt Cancer Center in Tampa, Fla., and her colleagues said in journal commentary.

"Male circumcision is associated with slight reductions in high-risk HPV, while licensed HPV vaccines protect with high effectiveness against only a limited number of HPV types. Therefore, the two interventions are likely to have important synergistic effects," the commentary concluded.

Additional interventions to reduce HPV infection, such as provision of vaccines for HPV prevention, will be essential to reduce invasive cervical cancer worldwide.

Male circumcision has been shown to decrease HIV, herpes simplex virus-2, HPV infections and genital ulcer disease in men, and also HPV infection trichomoniasis, and bacterial vaginosis and genital ulcer disease in their female partners, the researchers noted.

"Thus, male circumcision reduces the risk of several sexually transmitted infections in both sexes, and these benefits should guide public health policies for neonatal, adolescent, and adult male circumcision programs."

In the study, all of the HPV-uninfected female partners gave vaginal swabs they collected themselves at the start of the study and then after 12 and 24 months. The female participants were long-term sexual partners.