Approximately 11 million men and three million women in the U.S. are infected with oral human papillomavirus, or HPV, according to a new study led by University of Florida researchers. Men were also almost six times more likely to be infected with cancer-causing oral HPV strains. The study findings appeared October 16 in Annals of Internal Medicine.
HPV infection can be responsible for several cancers, including cancers in the back of the throat in an area called the oropharynx.
“The rates of oropharyngeal cancer among men have risen more than 300 percent in the past 40 years, making it the most common HPV-related cancer,” said study lead author Dr. Ashish A. Deshmukh, an assistant professor in the department of health services research, management and policy in the University of Florida College of Public Health and Health Professions.
To gain a better understanding of oral HPV infection and its concordance with genital HPV infection, the team analyzed data from the National Health and Nutrition Examination Survey 2011 – 2014, a nationally representative survey conducted by the National Center for Health Statistics that combines survey questions with laboratory testing.
The team found infection with HPV type 16, one of the strains responsible for causing most oropharyngeal cancers, was seven times more common among men than in women. Nearly two million men in the United States are infected with HPV 16.
Researchers also identified several demographic and behavioral risk factors. The age group with the highest prevalence of oral HPV infection among men was 50 to 69 years. This group is also experiencing rising rates of oropharyngeal cancer.
“One imagines sexually transmitted disease such as HPV as more common among young adults, but in this case it is middle-aged men who are most likely to harbor HPV 16,” said study team member Dr. Andrew G. Sikora, the Caroline Wiess Law Translational Research Scholar at the Baylor College of Medicine’s department of otolaryngology − head and neck surgery.
The team found that men and women with same-gender partners had a fourfold higher prevalence of oral HPV infection. Men who reported having more than 16 lifetime partners were 10 times more likely to have an oral HPV infection. The study is also the first to examine dual oral and genital HPV infection among men.
“In our previous research we found that one in two U.S. men have genital HPV infections,” said Dr. Kalyani B. Sonawane, an assistant professor in the UF department of health services research, management and policy and the study’s first author. “Because HPV can transmit from one site to another, a logical next question was to study concordance of oral and genital HPV.”
They found that oral HPV infection was five times more common among men with genital HPV infection and concordant oral and genital HPV infection was three times more common among men than among women. Men who had more than 16 lifetime oral sex partners were 10 times more likely to have dual oral and genital HPV infection. Men with a history of other sexually transmitted infections, such as chlamydia or gonorrhea, were three times more likely to have both oral and genital HPV infection.
The study is particularly important because the HPV vaccination rate among boys remains low and most men who are at risk for oropharyngeal cancer are over the vaccine eligibility age, Dr. Deshmukh said.
“Studies like ours are critical for guiding the design and development of strategies targeted toward prevention of oropharyngeal cancer among high-risk individuals,” he said.