Circumcised men at twice the risk for cancer-causing HPV, study shows
Circumcised men should be as vigilant in preventing oncogenic HPV infection as those who are uncircumcised, new research suggests.
Circumcised participants in a study presented at the annual meeting of the American Urological Association were twice as likely as their uncircumcised counterparts to have either of two HPV strains associated with penile cancer, researchers said. Their findings are not consistent with previous research.
“Classically, circumcision has been shown to be protective against HPV infection and ... we’re not completely sure why, but there was a higher rate of these higher-risk HPV infections in men who are circumcised,” study researcher Mickey Daugherty, MD, a urology resident at the State University of New York Upstate Medical University, told Infectious Disease News.
Daugherty said the high proportion of men in the United States who are circumcised could account for the prevalence of HPV in that population. Nonetheless, he said, the results show that circumcision alone is not a preventive measure.
Daugherty and colleagues analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2013 and 2014 on 1,520 men aged 18 to 59 years who had complete information on HPV infection and circumcision status.
The men provided penile swabs, which were tested for 37 HPV strains. The researchers stratified two strains of low-risk HPV linked to genital warts, HPV 6 and 11. They also stratified two strains of high-risk HPV linked to penile cancer, HPV 16 and 18.
Reflecting previous NHANES data, 45.2% of participants had some strain of genital HPV. In all, 2.9% were infected with one of the two low-risk strains, while 5.8% had one of the high-risk strains.
Most participants (77.8%) were circumcised. The higher risk for high-risk HPV was evident (OR = 2; P = .03), but there was no significant increase in risk for low-risk HPV in circumcised men (OR = 1.05; P = 0.9).
Despite the risk for circumcised men, only 7.8% of all participants — and 13.4% of those aged 18 to 29 years — received HPV vaccinations.
“This again brings up the importance of talking about vaccination,” Daugherty said. “Some of the HPV strains don’t necessarily cause major disease ... but at the same time, there are certain types of strains that you can prevent, and the big thing is people are unaware that the vaccine is available, and that this is something you can prevent.”
Although results have varied, earlier studies have generally shown that uncircumcised men are more likely to be infected with HPV than circumcised men. In a 2008 study published in The Journal of Infectious Diseases, researchers found that uncircumcised men were significantly more likely than those who were circumcised to be infected with a potentially cancer-causing HPV strain (adjusted OR = 2.51) and to be infected with several HPV strains (aOR = 3.56).
Previous NHANES data, meanwhile, have shown cause for alarm in all populations. Nearly half of 1,868 men had some kind of genital HPV strain. Another NHANES dataset showed that 25.1% of men and 20.4% of women in the U.S. have at least one high-risk genital HPV strain.
“Part of the issue is that HPV is much more prevalent than most people think or assume,” Daugherty said. “The concern is that most of them will not actually develop any sort of lesions from it, but at the same time, they could turn out to be infectious and infect others.” – by Joe Green
Daugherty M, et al. Abstract MP11-03. Presented at: The Annual Meeting of the American Urological Association: May 14-16, 2017; Boston, Mass.
National Center for Health Statistics. www.cdc.gov/nchs/data/databriefs/db280.pdf.
Hernandez BY, et al. J Infect Dis. 2008;doi:10.1086/528379.
Disclosure: The researchers report no relevant financial disclosures.