Researchers at Johns Hopkins University have found that people who engage in oral sex have an 80% higher risk of developing mouth and throat (oropharyngeal) cancers. The risk was particularly high for those who first had oral sex before age 18 and for those who had multiple oral sex partners. The findings were published in the journal Cancer.

Like sexual intercourse, oral sex can transmit the human papillomavirus (HPV). While most HPV strains are harmless, some can cause cancer in the cervix, penis, anus and the oropharynx (a term for several structures located at the back of the mouth, including much of the throat). According to the Centers for Disease Control and Prevention, HPV infection is responsible for 70% of all oropharyngeal cancer cases.

Between 2013 and 2018, the Johns Hopkins University researchers collected data on 163 people with HPV-related oropharyngeal cancer and 345 people without the disease to assess possible behavioral risk factors.

Comparing the two data sets, the researchers found that oropharyngeal cancer risk was positively correlated with a younger age at the time of first oral sex, having oral contact the first time they had sex, having more than 10 lifetime oral sexual partners, a greater age difference between partners (in particular a person under 23 having a partner at least 10 years older), having a partner who had extramarital sex and oral sex “intensity” (more sex partners within a short period of time, which correlates with HPV exposure). Deep kissing was also linked to higher risk.
 

“Our study builds on previous research to demonstrate it is not only the number of oral sexual partners but also other factors not previously appreciated that contribute to the risk of exposure to HPV orally and subsequent HPV-related oropharyngeal cancer,” lead study author Virginia Drake, MD, told Yahoo!

However, the researchers emphasize that their results should not be used to advocate for abstinence. Most of the study participants were heterosexual men between 50 and 69, so most of them never had the opportunity to be vaccinated against the HPV virus. The first HPV vaccine was approved in 2006.

“No one should take this to mean ’Don’t have oral sex,’” H. Hunter Handsfield, MD, a professor emeritus of medicine at the University of Washington Center for AIDS and STD, told U.S. News and World Report. Rather, he said, the results underscore the importance of HPV vaccination for preteen girls and boys. (The HPV vaccine is now approved for men and women up to age 45.)

For more on how number of lifetime sexual partners affects health, read “People With 10-Plus Lifetime Sexual Partners More Likely to Develop Cancer.” And to learn more about how HPV vaccination can reduce oropharyngeal cancer risk, read “FDA Approves HPV Vaccine for Prevention of Oral Cancer.”