Why Is There No Screening for HPV-Related Throat Cancer?
While cervical cancer in women has been steadily declining in the U.S., another cancer caused by the same virus has been quietly, lethally rising — especially in men.
Human papillomavirus (HPV) is the most common sexually transmitted disease (STD) in the U.S, according to the Centers for Disease Control and Prevention (CDC). Most people know that HPV can cause cervical cancer in women, but the virus’ potential to cause cancer in men often goes unspoken. The most common HPV-related cancer in men? Oropharyngeal cancer, or cancer of the throat.
The Pap test exists as an effective way to screen for cervical cancer. So why isn’t there a similar Food and Drug Administration (FDA)-approved screening test for cancer of the throat?
Cervical cancer: Not the only HPV-related cancer
Of the more than 150 types of HPV, some can cause genital warts, while others can cause certain types of cancer. In nine out of 10 cases, however, HPV infections go away by themselves within two years. It’s the other, more persistent cases that may cause problems like cancer.
“It’s estimated that 80 percent of us, men and women, will be exposed at some point in our lives to the [HPV] virus,” said Erich Sturgis, M.D., a head and neck surgeon at the University of Texas MD Anderson Cancer Center. “Most of us will never have any consequence of that.”
In the past, cervical cancer was one of the most common causes of cancer death in American women, according to the American Cancer Society. But since the introduction of the Pap test for cervical cancer screening in the 1950s, along with the more recent development of the HPV vaccine, the rate of deaths from cervical cancer has decreased by more than half. Rather than testing for HPV, the Pap test helps detect cervical cell changes at their earliest stages, often before the cells even become cancer. This allows for treatment and prevention of cancer altogether.
But cervical cancer isn’t the only cancer that HPV can cause. It also can lead to cancer of the vulva, vagina, penis, anus, or throat.
Some of these cancers are relatively rare — for example, there are only about 1,000 cases of penile cancer per year in the U.S., and they are not as difficult to detect because the lesions on the penis would be more easily noticed, Dr. Sturgis said.
On the other hand, HPV-related cancers of the throat (specifically the tonsils and base of the tongue) are much more common than many people realize and are difficult to catch early. While genital HPV can be transmitted through sexual activity, oral HPV may be passed during oral sex or even open-mouthed kissing, some studies say. In 2013, actor Michael Douglas made headlines for attributing his throat cancer to cunnilingus.
In men, an estimated 13,200 cases of HPV-related throat cancer are diagnosed each year in the U.S, according to the CDC. Women can get these throat cancers too, but it’s more than four times less common. The rates of these cancers in both men and women have been rising in recent years, but more dramatically in men.
It is not yet widely understood that HPV is linked to throat cancer — unsettling, considering the average annual number of throat cancers caused by HPV in the U.S. has already surpassed cervical cancers, according to the CDC.
Lois Ramondetta, M.D., a professor of gynecologic oncology and reproductive medicine at the University of Texas MD Anderson Cancer Center, told HealthCentral she still encounters confusion, even among health care providers, about the risk of oropharyngeal cancer from HPV.
“It takes a while to trickle down medical information through the world,” she said.
But the spread of this information could be life-saving.
Is screening an option?
So how do you screen for HPV-related cancers in the oropharynx, an area farther back than where you get a normal strep test? The short answer is you can’t, Dr. Sturgis said.
“For the oropharynx — the tonsils and the base of the tongue — the surface of that area is very cryptic,” he said. “It has these deep pits and crevices. It’s not an easy, smooth surface to examine like the cervix.”
HPV-related throat cancers probably start deep in these crevices, he said. Cancer screening aims to detect an early cancer or precancer, but these crevices are not an area of the body that tests can readily visualize.
“I can tell you that I’ve never seen an HPV-related precancer [of the oropharynx],” he said.
While health care providers could theoretically detect HPV in the throat using the same test used to detect HPV in the cervix, Dr. Ramondetta said, it’s unclear what to do with that data.
“What do you do if you find HPV in the mouth? You get people scared, and we have no [cancer] screening test,” she said. “And a lot people have HPV in their mouth and on their genitals, and most of the time it goes away. So at this point, it is not alone a reasonable screening test [in the throat].”
Beyond these cancers’ increasing prevalence, even more concerning is that they typically don’t cause any symptoms, like a sore throat or a visible ulcer, Dr. Sturgis said.
“So the reason [people] show up at the doctor is they feel a lump in their neck […] Usually a man says, ‘I was shaving this morning and I noticed this lump, it doesn’t cause any pain’ … And what that is is a lymph node where the cancer has spread to,” Dr. Sturgis said. “And they get a needle biopsy of that, and it shows that they have a cancer — and typically it’s stage four because it’s spread to the lymph nodes already.”
The average age of diagnosis for these cancers is 61 for men and 62 for women. Following diagnosis of late-stage oropharyngeal cancer, patients typically undergo an extensive treatment of chemotherapy with radiation, according to the American Cancer Society.
If someone with oropharyngeal cancer is treated at a major cancer center, there is about an 80 percent five-year survival rate, even if the cancer has spread to the lymph nodes, Dr. Sturgis said. But the effects of radiation are lifelong.
“At least five percent of these men later need to have their jaw removed because of the effects of radiation […] It affects the swallowing horribly,” he said. “We see a large number of people needing a feeding tube during treatment, and in some people, it ends up being permanent. [It’s] very difficult.”
Radiation treatment can also affect the carotid arteries, he said, so people may have accelerated atherosclerosis and an elevated long-term risk for stroke. And beyond the physical cost, the monetary cost is immense: The one-year medical cost is more than $100,000, Dr. Sturgis said.
While there is currently no FDA-approved screening test available for HPV-related oropharyngeal cancers, Dr. Sturgis said, physicians and researchers are actively working to address the issue. For example, at the University of Texas MD Anderson Cancer Center in Houston, Dr. Sturgis is opening a clinical trial to find a high-risk group of men in their 50s to screen for HPV-related cancers. To do this, he and colleagues will use a blood test to determine whether the men have not only been exposed to HPV but also have evidence of antibodies to certain cancer-causing HPV proteins. Those men will be deemed high-risk and undergo targeted screening of the throat.
Honing in on a high-risk group, rather than just testing the general population, may be the key to more effective screening, Dr. Sturgis said.
What’s the solution?
While there is no viable screening test option, there is still a highly effective way to protect people from oropharyngeal cancers caused by HPV: the HPV vaccine. The current HPV vaccine recommendation is a two-dose vaccine recommended for 11- to 12-year-olds — both girls and boys. However, it can be given between the ages of 9 and 26.
“It’s a remarkable opportunity that we have a vaccine to prevent cancer, and that’s how we want to talk about this,” Dr. Sturgis said. “This is a vaccine that can prevent several cancers that are devastating to people, and we would encourage parents to […] not let their kids miss out on this opportunity.”
More than half of oropharyngeal cancers in the U.S. are linked to HPV type 16, which is covered by the HPV vaccine. Most of the other types of HPV that cause these cancers are also covered by the latest HPV vaccine.
As of 2017, nearly half (49%) of teens were up to date on the HPV vaccine. The leading cancer centers in the nation have joined together to support increasing these vaccination rates as a key course of action to help prevent the continued rise of these cancers. The best protection comes from getting two doses of the vaccine between six and 12 months apart, the CDC says.
“Number one, for men, we need to make sure that our boys are all getting vaccinated,” Dr. Sturgis said. “Number two, we have young men and adolescents that for whatever reason may have missed vaccination, we want to recommend catch-up HPV vaccination.”
For example, if a college student has never been vaccinated against HPV, they need to know that they can still do so up to age 26. For men (and women) older than age 26, Dr. Sturgis, it’s important to be aware of any changes in throat symptoms or a new lump in the neck and see their doctor — ideally an ear, nose, and throat doctor — right away.
“We hope in the near future that there will be testing available for men,” Dr. Sturgis said. But for now, he said, early vaccination is our most effective course of action.
To parents who may be hesitant to get their kids vaccinated against HPV, Dr. Ramondetta emphasized just how simple it is to protect kids from these cancers, compared with risk-reducing tactics for other types of cancer, like regular exercise and wearing sunscreen.
“Those things are repeated things that you need to do every day to try to reduce your risk,” she said. “All you’ve got to do for your kid [to prevent HPV-related cancers] is give them these two shots. There’s just no reason that we should even see these cancers on this planet anymore.”