Feb. 28, 2011 -- About half of adult men have genital human papillomavirus (HPV), a sexually transmitted infection that has been linked to certain cancers, according to a study funded by the National Cancer Institute (NCI).
Genital HPV is the most common type of sexually transmitted infection. Many people infected with HPV do not know they have it. There are many different strains of HPV. More than 40 of them affect the genitals. Some types of genital HPV cause genital warts, while others can lead to cancer. Persistent infection with a high-risk strain of HPV is the leading cause of nearly all cervical cancers in women. Genital HPV may also lead to less common, but serious, cancers of the penis, anus, vulva, and vagina and some cancers of the oral cavity and head and neck.
You are more likely to catch HPV if you have multiple sexual partners.
The NCI-funded study involved more than 1,000 adult men aged 18 to 70 years old that lived in the United States, Brazil, and Mexico. All men were HIV-negative and had no history of cancer. The average age of the study participants was 32. The men were examined and tested for signs of a genital HPV infection every six months for an average of more than two years.
Researchers noted a high rate of HPV infection in men across all age groups. The finding suggests that men are at a high risk for catching new HPV infections throughout their life.
Cancer-causing types of genital HPV were more likely in men who had multiple sex partners, regardless of sexual preference.
- Men who had sex with more than 50 female sexual partners were 2.4 times more likely to have a cancer-causing HPV infection than men who reported having only one or no sexual partners.
- The chances of cancer-causing HPV infection was 2.6 times higher among the men who had anal sex with at least three men compared to those who had no recent partners.
Most HPV infections usually go away on their own. The time it takes for the infection to clear varies. In the study, it took "significantly longer" for infections with any type of HPV to clear in men aged 18 to 30 than in other age groups.
The results will be published in the March 1 online edition of The Lancet. They emphasize an often-raised question: Should men, including older men, be vaccinated against cancer-causing types of HPV? Study authors say their results provide much-needed information about the occurrence of HPV infection among men and how long such infections persist. This information, they say, is essential for guiding prevention strategies and determining whether male HPV vaccination would be cost effective.
In December 2010, the FDA approved the Gardasil vaccine for the prevention of anal cancer from HPV strains 6, 11, 16, and 18 in people aged 9 through 26. It is also approved to prevent genital warts caused by HPV strains 6 and 11 in males and females.
In an accompanying comment, Paris-based researcher Joseph Monsonego, MD, says "HPV vaccination of men will protect not only them [from cancer and disease] but will also have implications for their sexual partner.”