March 2, 2009
Circumcised men were more likely to clear human papillomavirus than other men, a recent US study found. Compared with women, data on factors for men acquiring and clearing HPV are limited, reported Dr. Anna R. Giuliano of the Tampa, Fla.-based H. Lee Moffitt Cancer Center and Research Institute and colleagues.
To investigate these factors, they monitored 285 men ages 18-44 every six months for approximately 18 months, gathering risk factor information through a self-administered questionnaire at each visit. Overall, 29 percent of the men became infected with HPV during one year, and 19 percent acquired an oncogenic strain.
Men who reported more than 16 lifetime sex partners had about three times the HPV infection risk of those with fewer partners. They were also nearly 10 times more likely to have acquired a potentially cancer-causing strain. Circumcised men were three times more likely to clear all HPV types, and six times more likely to clear oncogenic HPV types.
The reasons for the circumcision-related findings are not clear, the authors said. It is possible circumcised men are less apt to get skin abrasions during sex, offering less chance for virus particles to enter their bodies, the researchers hypothesized.
"The key factor associated with acquisition of HPV was lifetime number of sex partners, whereas circumcision was the most significant determinant for clearance of any HPV infection and oncogenic HPV infection," the authors concluded.
The full report, "Factors Associated with Acquisition and Clearance of Human Papillomavirus Infection in a Cohort of US Men: A Prospective Study," was published in the Journal of Infectious Diseases (2009;199:362-371).