We usually think of HPV as the cause of cervical cancer and most of us are familiar with HPV screenings as part of the pap smear process. But head and neck cancers are increasingly becoming a concern because studies show that they are actually on the rise, especially oropharyngeal cancer in men. Rates have been increasing about 2.9% per year in men and have remained relatively stable in women. And now, the number of cases of HPV-related oropharyngeal cancer in men is now about the same as the number of cases of cervical cancer in women.
This begs the question why and a new study out this week in the Annals of Internal Medicine is getting a lot of attention because it attempts to uncover an explanation for this phenomenon.
What is HPV?
HPV or the Human Papilloma Virus is the name given to a group of related viruses. There are over 150 types of HPV. The virus likes to live on mucous membranes and is spread by sexual contact. Some types can cause warts, some cause cancer of the cervix, vagina, vulva, penis, and anus as well as the head and neck (especially the base of the tongue and tonsils). Since HPV usually causes no symptoms though, most men and women can get HPV— and pass it on—without realizing it.
What did this new study find?
This new study looked at the prevalence of HPV infections in men and women who participate in the NHANES study. NHANES is a huge study conducted by the CDC that assesses the health of people in the United States by actually examining thousands of people every year. This paper examined data from about 9,000 people.
The authors found that overall 11.5% of men and 3.2% of women in the study or about 11 million men and 3.2 million women nationally have an oral HPV infection. But there are some types of HPV that are more likely to cause cancer than others and they found that these high-risk types were also more common in the oral samples they took from men (7.3%) than women (1.4%). The prevalence of high-risk oral HPV infection is actually highest in men ages 40 to 59.
Besides the gender differences, some people are more likely than others to have a high-risk oral HPV infection.
The highest rates were in men with 11 or more oral sex partners. The prevalence in this group was 7 to 10 times higher than among those with 0 to 1 partners. Men with more than 11 vaginal sex partners also had a 3 to 4 times higher prevalence than those with 0 to 1 partners. Men who reported sex with two or more same-sex partners were also at higher risk than those who reported zero.
I spoke to the author of this study and he pointed out a particularly important finding. Men who had a genital HPV infection actually had a four times higher prevalence of having a concurrent oral HPV infection than men who didn’t have a genital infection. In a previous study, the authors found that about one-third of men actually have a high-risk genital HPV infection. So, in the future, this might help doctors identify those at risk.
The other people that had a higher prevalence were those who smoked—either cigarettes or marijuana. Smoking doesn’t cause the virus so this might be because of the inflammation that smoking causes in the mouth and throat, which makes these cells more vulnerable to the virus.
Since most people who have an HPV infection don’t know it, it’s important to recognize the symptoms of oral cancer. Some studies suggest that a lump in the neck is the most common. Other symptoms also include persistent coughing, sore throat or ear pain that doesn’t go away, and voice changes. If you have any of these symptoms you should talk to your doctor.
What can we do to prevent oral HPV infection?
One of the best ways to prevent oral HPV infection is getting the HPV vaccine. The vaccines don’t cover all of the high-risk types, but the study did find that people who had gotten the vaccine were less likely to have the types of HPV that the vaccine covers. The study also found that the high-risk type of HPV most commonly found in men was type 16, which is covered by the vaccine. The vaccine is recommended for men and women through age 21-26. It’s not recommended for older adults because most have already been exposed to HPV and studies have included older age groups. Other ways to prevent HPV infection include using protection during sex, which can help prevent transmission of the virus and not smoking cigarettes and/or marijuana.