The human papillomavirus (HPV) isn't just the most common sexually transmitted infection—it's also a common cause of preventable cancers. In fact, according to a new study from the Centers for Disease Control and Prevention (CDC), there was an increase in HPV-related cancers between 1999 and 2015. While cervical cancer rates declined, the rates of other HPV-related cancers actually increased.
HPV is a known cause of cervical cancer, along with some types of vulvar, vaginal, penile, anal, and oropharyngeal (e.g. throat) cancers. Having an HPV infection certainly isn't a guarantee that you're going to develop cancer—the body does an excellent job of clearing these infections and, in many cases, a person never knows they had one. But, in some cases, the virus causes changes to cells in specific locations on your body that can develop into cancer.
According to the CDC report, there were 30,115 new cases of HPV-associated cancers in 1999. But in 2015, that number jumped to 43,371 new cases.
For the study, researchers from the CDC analyzed data from cancer registries that cover nearly 98 percent of the U.S. population.
Interestingly, different types of HPV-related cancer showed different trends: Between 1999 and 2015, rates of cervical cancer decreased 1.6 percent each year, vaginal squamous cell carcinoma rates decreased 0.6 percent each year, and penile cancer rates were stable.
But rates of throat cancer increased 2.7 percent each year among men and 0.8 percent annually for women. Anal cancer rates also increased for men and women—2.1 percent and 2.9 percent each year, respectively. Vulvar cancer rates increased 1.3 percent each year as well.
That means that throat cancer was the most common HPV-associated cancer in 2015, with 18,917 cases reported that year, the report says.
First, let's take a second to applaud the decrease in cervical cancer rates.
That decline is probably due to a combination of factors, including increased HPV vaccination rates and the use of more sensitive screening tests for cervical cancer, such as HPV testing alone or in combination with the Pap smear, Jason Wright, M.D., chief of gynecologic oncology at NewYork-Presbyterian/Columbia University Irving Medical Center, tells SELF.
But it's still too soon to conclusively know what effect HPV vaccination is having overall, study co-author Mona Saraiya, M.D., M.P.H., a medical officer and team lead in the CDC’s Division of Cancer Prevention and Control, tells SELF. "It's been predicted to take decades to see a change in cancer [rates]," she says.
And, although they're getting better, we know vaccination rates still aren't where experts would like them to be. "We would like to see fewer of these cancers diagnosed, but we know that our HPV vaccination rates in the U.S. have been extremely low over the past few years," Lois Ramondetta, M.D., professor of gynecologic oncology and reproductive medicine at MD Anderson Cancer Center, tells SELF. "We have many years before these vaccinated individuals will be in the age groups most at risk for the six cancers related to HPV."
So why are throat and anal cancers still increasing? Experts have a few theories.
One idea is that changing sexual behaviors—including having unprotected oral sex and anal sex—may be part of the reason for these increases, Dr. Saraiya says. As SELF wrote previously, a recent survey found that about a third of people in the U.S. say they never use protection during oral sex, which can put you at risk for HPV and many other sexually transmitted infections.
"We know that those cancers tend to be associated with certain behaviors that are more prominent in college-age folks," Electra Paskett, Ph.D., co-leader of the cancer control research program at The Ohio State University Comprehensive Cancer Center, tells SELF. "We believe that what we’re seeing now is the effect of that."
White men, who have the highest rate of throat cancer compared to other demographics, also have the highest number of lifetime oral sex partners and say they first performed oral sex on a partner at a younger age than people of other racial or ethnic groups, according to the new CDC report.
And, while there currently are recommended screening guidelines for cervical cancer, there aren't universal guidelines for screening for other HPV-associated cancers, which is a problem, Dr. Ramondetta says. "It is imperative we find ways to screen effectively for these cancers," she says.
The report also notes that smoking probably isn't behind the increased rate of throat cancer because smoking rates have been decreasing in the U.S.
This is all a reminder to take your HPV risk seriously to prevent several types of cancer.
If you’re under the age of 26, you really should get the HPV vaccine, as it’s been proven to help protect against the types of HPV that are linked to cancer, G. Thomas Ruiz, M.D., lead ob/gyn at MemorialCare Orange Coast Medical Center in Fountain Valley, Calif., tells SELF. “The most important thing is to vaccinate boys and girls. That really is the single most important defense against all HPV-related cancers,” he says.
Safe sex practices are also important. Condoms and dental dams may help prevent the spread of HPV, per the CDC, so it's important to use them every time you have oral and anal sex, Dr. Ruiz says.
When it comes to cancer screening, make sure you follow the current screening guidelines. For cervical cancer screening in particular, the U.S. Preventative Services Task Force recommends that women between the ages of 21 and 29 get a Pap test every three years; those between the ages of 30 and 65 should get a Pap test every three years, or a test for HPV every five years, or a combo of both every five years.
As we mentioned, there isn't a screening guideline for throat cancer, so it's wise to be familiar with the most common symptoms. You'll want to keep an eye out for a lump on your neck, according to the National Cancer Institute. That, along with a sore throat, "is the hallmark of that cancer," Dr. Paskett says.
And because many of us aren't getting screened for symptoms of anal cancer, it's worth noting that you can request a digital rectal exam from your ob/gyn during your annual doctor's visit. Some general clinicians and urologists are also certified in anal screening, but this isn't widespread, Dr. Paskett says. If you think you may be at risk for HPV infection (if you've engaged in anal sex without a condom, if you've received oral-anal sex without a barrier, if you're unsure of your partner's HPV status, or you're just not sure), don't be shy about asking your doctor about how frequently you should be screened.
Overall, experts stress that the HPV vaccine really is your best defense against developing an HPV-related cancer. "I cannot stress how important it is to get this vaccine," Dr. Ruiz says.