Women Benefit From Male Circumcision, Too
Rakai researchers may make new breakthroughs in prevention by drawing on what is possibly the world’s largest foreskin collection.
Women in the developing world looking for protection from cervical cancer have another reinforcement to add to their arsenal: male circumcision. Bloomberg School researchers Maria Wawer, MD, MHSc, and Aaron Tobian, MD, PhD, have finished a multiyear study that shows the efficacy of male circumcision as a means of reducing the rate of HPV infection among women.
Human papillomavirus (HPV) can cause genital warts and cervical cancer. In the developing world, where 85 percent of infections occur, the situation is dire: WHO estimates that about 33 percent of East African women are harboring HPV. Cervical cancer is the leading cause of cancer death among women in Uganda, where the study took place.
Women partnered to circumcised men have a 25 to 30 percent reduction over time in the number of HPV infections, according to Wawer, a professor of Population, Family and Reproductive Health, and Tobian, an assistant professor of Pathology at the School of Medicine. Though encouraged by the finding, Wawer cautions that couples should still practice other forms of safe sex. “Don’t think of this as a magic bullet,” she says. “It’s part of a program of protection.”
In the study, 5,000 uncircumcised HIV-negative men enrolled, together with their HIV-negative female partners. Then researchers randomly assigned men to be circumcised, either immediately or at the end of two years. Everyone was tested for infections at the beginning, middle and end of the study. Circumcised males had lower rates of HPV infection, likely because the procedure makes carrying the disease more difficult, says Wawer. And, as suspected, so did their female partners.
The parallel effect occurred because male circumcision both reduced the number of new male infections and increased the proportion of men with HPV at the time of enrollment who subsequently cleared the virus. “We hypothesize that the foreskin mucosa is an important site for infection,” notes Wawer. “Without this focal site, there is higher clearance at other sites along the male genital tract and less reinfection of other sites by the virus when it is no longer shed by [cells within] the foreskin mucosa.”
Since fewer men were infected, fewer transmitted HPV to their partners. A bonus: Wawer says that about 40 percent of women in the study reported being more sexually satisfied after the man’s circumcision, mainly because of better hygiene.
She and her colleagues have been studying a broad range of HIV-related matters since the late 1980s in the Rakai region of Uganda, where they founded the Rakai Health Sciences Program. The researchers made headlines several years ago with a study showing that circumcision dramatically reduced men’s chances of contracting HIV from infected female partners.
The Program provides thousands of circumcisions at no cost to men through PEPFAR funding. As a result, the site has what is possibly the world’s largest collection of foreskins, which are “immediately whisked away,” says Wawer, “because we do have a real kick-ass lab right there in rural Uganda.” The Rakai researchers are using the tissues to study how immune defenses in the mucous membranes protect the body from infections. Inadvertently, they are also discovering hundreds of new bacteria under the foreskins—enough that “everybody working on the project could probably have a bacterium named after them,” Wawer says.