Women are less likely to develop cancer of the cervix if their partners are circumcised men rather than men who are not circumcised, said a report in The New England Journal of Medicine (Vol. 346, No. 15: 1105-1112).

Experts believe a penis that has been circumcised is less likely to harbor human papilloma virus (HPV), a virus associated with almost all cases of cervical cancer.

According to the American Academy of Pediatrics, about 1.2 million male babies or about 65% percent of all male newborns are circumcised each year in the US. Only about 20% to 25% of male babies worldwide are circumcised.

Circumcision has become controversial in recent years. Its advocates in the medical community argue that it prevents urinary tract infections in male babies. It also lowers sexually transmitted infections with HPV that cause genital warts in men. Finally, penile cancer arises less often in men who were circumcised as babies.

Those who do not support the use of circumcision believe that these reasons don’t make up for the pain and possible “mutilation” it causes, as well as the occasional complications.

Now a group of international researchers, led by Xavier Castellsagué, MD, of the Llobregat Hospital in Barcelona, Spain, have uncovered another reason to favor circumcision. They found that women whose partners were uncircumcised were more likely to develop cancer of the cervix.

The researchers studied the male partners of women with cervical cancer.

Castellsagué and his colleagues questioned whether the male partners of women with cervical cancer were circumcised. In addition, they studied male partners of women without cervical cancer. To be as accurate as possible, they only studied male partners in monogamous relationships (males with one sexual partner).

The researchers also tested for HPV infection in the males by taking specimens from their penises. The results were matched with whether the men were circumcised.

The first discovery was that men who weren’t circumcised were more than twice as likely to be infected with HPV. In both groups, the chance of HPV infection increased with high-risk sexual activity such as unprotected sex, early age of first sexual activity, and number of partners.

But even more striking was the effect on their partners. Women whose male partners were uncircumcised and had high-risk sexual behavior were two to five times more likely to develop cervical cancer. This high rate of cancer was almost certainly caused by the high rate of HPV infection in these men.

In an accompanying editorial, Hans-Olov Adami, MD, PhD, of Sweden and Dimitri Trichopoulos, MD, PhD, from the Harvard School of Public Health commended the study. But they cautioned that one can never be completely sure of studies that rely on sexual histories.

Nevertheless, they were confident enough in the study to agree that an uncircumcised man is more likely to have HPV infection and that his partner will more readily develop cervical cancer.