Most women know by now that the human papillomavirus (HPV), the most common sexually transmitted infection in the United States, can cause cervical cancer. That's why we get Pap or HPV tests every few years, and why the HPV vaccine is now recommended for adolescents and young adults.
Thanks to those efforts, the conversation around HPV is shifting: According to data published this week by the Centers for Disease Control and Prevention (CDC), throat cancer has now dethroned cervical cancer as the most common HPV-related cancer.
The new analysis, published in the CDC’s Morbidity and Mortality Weekly, found that cervical cancer rates decreased 1.6% per year between 1999 and 2015. At the same time, however, rates of oropharyngeal squamous cell carcinoma—the most common type of head, neck, and throat cancer—increased by 2.7% per year among men and 0.8% per year among women. In 2015, more than 15,000 cases of throat cancer were diagnosed in men, and more than 3,400 were diagnosed in women.
RELATED: What Does It Mean to Have an Abnormal Pap Smear—and What Should You Do Next?
These numbers come from cancer registries across the United States, and they cover more than 97% of cancers diagnosed during the study period. While those registries did not typically determine whether HPV had caused individual cases of cancer, statistics suggest that the virus was to blame in many of them: Research shows that HPV DNA is found in 91% of cervical, 91% of anal, 75% of vaginal, 70% of oropharyngeal, 69% of vulvar, and 63% of penile cancers in the United States.
Between 1999 and 2015, rates of anal and vulvar cancers also increased, while rates of penile cancers remained stable. Overall, more than 43,000 HPV-associated cancers were reported in 2015, compared to just over 30,000 in 1999.
In other words, there’s some good news and some bad news. On the plus side, the drop in cervical cancers “represents a continued trend since the 1950s as a result of cancer screening,” the authors wrote in their report.
Cervical cancer rates also decreased more among traditionally underserved populations (Hispanics, American Indian and Alaska Natives, and African-Americans) than among white women, suggesting that advances have been made to narrow screening and treatment disparities between these groups. Rates were still highest among Hispanics and African-Americans in 2015, however, indicating that health-care needs of some groups still “are not fully met,” the authors wrote.
RELATED: Cervical Cancer: 9 Symptoms Every Woman Needs to Know
The bad news, then, is that other types of HPV-associated cancer are on the rise. This could be due to “changing sexual behaviors,” the authors wrote—namely, an increase in unprotected oral and anal sex, which are both risk factors for HPV infection.
White men have a higher rate of HPV-related throat cancer compared to other racial and ethnic groups. That may be related to the fact that they also tend to have more lifetime oral-sex partners, and to first engage in oral sex at an earlier age, the authors wrote. (The authors note that smoking is also a risk factor for oropharyngeal cancers, but that smoking rates have declined in recent years. Studies have also shown the increase in these cancers “is attributable to HPV,” they wrote.)
Currently, U.S. health organizations only recommend regular screenings for one type of HPV-associated cancer: cervical cancer, in the form of Pap tests and/or HPV tests for women 21 to 65. The authors of the new report don’t suggest that this should change, but they do say it’s important for researchers to continue tracking trends—and changes—in rates of different types of cancer.
They also point out the importance of HPV vaccination, which is recommended for both girls and boys at age 11 or 12; it’s also available to adult women who didn’t get it when they were younger.
RELATED: The HPV-Related Cancer on the Rise in Men
Although it might be too soon to see how vaccination has affected actual cancer rates, the authors write, studies have reported reductions in HPV infection, genital warts, and cervical precancers. (In related news, another new CDC report shows that more teenagers are getting the vaccine now than ever before.)
This isn’t the first report to show an increase in oropharyngeal cancers, especially among men, in recent years. A 2017 study in the Annals of Oncology came to a similar conclusion, although the authors stressed that the overall risk of developing such a cancer was still very low for most people.
Amber D’Souza, PhD, lead author of that paper and associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, spoke with Health after her study was published. Despite her team’s findings, she said that most people who test positive for HPV will never actually develop cancer—and that routine screenings for throat cancer would likely do more harm than good.
RELATED: These Are the Top Causes of Vagina Pain
“Most people perform oral sex in their lives,” she said, “and this study really suggests that the risk remains low for oropharyngeal cancer and for oral HPV infection.”
That being said, any unusual symptoms that last longer than two weeks—including a sore throat that doesn’t go away, trouble swallowing or moving the tongue, ear pain, or a lump in the mouth or neck—should be checked out by a doctor, Abie Mendelsohn, MD, assistant professor-in-residence at the David Geffen School of Medicine at UCLA, previously told Health. “If we can identify [throat] cancer within about 6 to 8 weeks of when somebody first feels something, prognosis is usually excellent,” he said.