Call for More HPV-Related Primary Prevention

Tara Haelle

December 04, 2019

SAN FRANSCISCO — Dentists need to be proactive about promoting prevention strategies for oral cancer, including advising patients to get vaccinated against the human papillomavirus (HPV), experts said here at the World Dental Congress 2019.

"As a provider, I believe I have a responsibility to prevent HPV-associated cancers and therefore to promote the only cancer-prevention tool that we have available," said Alessandro Villa, DDS, PhD, from Brigham and Women's Hospital in Boston.

"Even if we're not the ones giving the vaccine, if we initiate the conversation and refer our patients to their pediatrician, the data show that this will translate into increasing HPV vaccination rates," he told Medscape Medical News.

Lack of provider recommendation is the leading reason rates of HPV vaccination lag behind rates of other vaccinations advised by the Centers for Disease Control and Prevention (CDC), Villa reported. But "dental providers are willing and have the knowledge to incorporate HPV-related primary prevention into their practice."

Last year, the American Dental Association (ADA) adopted a policy that urged "dentists to support the use and administration of the HPV vaccine."

The CDC recommends that all children 11 and 12 years old receive two doses of Gardasil (Merck), which protects against nine oncogenic strains of HPV, including the high-risk HPV 16 and 18 strains.

Increasing HPV vaccination rates could lead to a decrease not only in cervical and anal cancers and genital warts, but possibly also oropharyngeal cancers.

"The reason it's recommended around this time is because we have the best immune response for this vaccine and because we want to vaccinate our patients before any exposure to any of the HPV genome types," said Villa.

For patients receiving the vaccine after the age of 14, three doses are required. Men and women 27 to 45 years of age are now eligible for the vaccine.

"Increasing HPV vaccination rates could lead to a decrease not only in cervical and anal cancers and genital warts, but possibly also oropharyngeal cancers," Villa explained. "We'll be able to see this decline in a few years because it takes about 10 to 15 years for the virus to cause cancer."

In the first study to show a significant drop in oral cancer as a result of HPV vaccination, the prevalence of oral infection with HPV 16, 18, 6, and 11 strains was reduced by 88.2% (P = .008). And no vaccinated men developed an infection, but 2.1% of unvaccinated men did (P = .007).

In addition, the 2-year overall survival rate has been shown to be significantly worse when head and neck squamous cell carcinoma is related to HPV infection than when it is unrelated (68% vs 95%; adjusted hazard ratio [aHR], 6.61; P = .003), as has the recurrence-free survival rate (55% vs 88%; aHR, 3.72; P < .001).

Risks and Symptoms

The number of oral sex partners a person has had affects their risk for oral HPV, and men tend to be at higher risk for HPV infection than women, especially if they smoke.

One study showed that women who have had one partner or no partner are at the lowest risk for infection: 0.1% for HPV 16 and 0.7% for any HPV strain linked to cancer. That risk increases to 1.5% for any oncogenic strain for women who have had at least two oral sex partners.

And for men who have had up to four oral sex partners, risk for any oncogenic HPV strain is 2.8%, but that risk more than doubles, to 7.3%, if the man smokes. For men who have had at least five oral sex partners, the risk is 7.4% for nonsmokers and 14.9% for smokers.

Some symptoms of HPV-caused oropharyngeal cancer can resemble other common ailments, although they are persistent, such as a sore throat or trouble swallowing, fully opening the mouth, or moving the tongue. Ear pain, voice changes, weight loss, and enlarged lymph nodes can also indicate oropharyngeal cancer, as can coughing up blood and the appearance of a lump in the back of the mouth, throat, or neck.

Aside from looking for lumps, lesions, and dysplasia in the mouth, providers assessing a patient for oropharyngeal cancer should look for external swelling or asymmetry in the jaw or neck, palpate the lymph nodes, and assess the patient's jaw movements. The gold standard for diagnosis is a tissue biopsy, said Villa.

Most oral HPV infections clear on their own within a year, but for patients with head and neck squamous cell carcinoma of unknown primary, routine HPV testing is recommended because persistent oral HPV 16 infection is a risk factor for a poor prognosis.

"We have a responsibility to our patients to educate them and make them aware of these infections," said Villa.

This is particularly true because there are no screening programs for HPV, largely because of the lack of treatment for the infection, he added.

Awareness

"I think there's emerging awareness with this specific type of oral cancer," Danielle Marquis, DDS, from San Francisco Dental, told Medscape Medical News. "In the United States, we have 50 accredited dental schools that really do emphasize oral cancer prevention and the role that dentists are supposed to be playing in their daily practice and patient interactions."

"Just understanding, with this particular cancer on the rise, what action steps can be taken through the vaccination protocol that has developed in the past 10 years is huge, and getting the information into the hands of dentists is huge," she noted.

But more work needs to be done to increase awareness in the dental community, said Alice Horowitz, PhD, a dental hygienist in Chevy Chase and an associate professor of behavioral and community health at the University of Maryland in College Park.

At an event held on her campus last year, in which the School of Public Health partnered with the dental school to provide free oral cancer examinations, "I started asking questions about what they knew about the HPV vaccine," she told Medscape Medical News.

"They knew very little," she explained. "They weren't up on vaccination dosage and they weren't educating their patients." If that is happening at one school, it's likely happened at others, she pointed out.

"I think we haven't really done a good job of increasing awareness in dentistry, but I think it's growing because ADA has a huge interest in this," Horowitz said.

Dentists could put their photo on the wall with a sign saying, "Ask me about the HPV vaccine," Horowitz suggested, echoing Villa's proposal that dentists passively promote the vaccine by having materials in the office.

"It's very, very important that we help foster the integration of medicine and dentistry," she said, which includes helping patients make an appointment for the vaccine.

Dentists could soon be able to administer the vaccine. Earlier this year, a bill was passed in Oregon that expands the scope of practice to include the administration of vaccinations for dentists who have completed continuing education and can meet vaccine storage and reporting requirements. Other states are considering similar legislation, Villa said.

"We don't know yet if this is the best public health approach," he added, "but definitely it's a new thing for us as dentists and it's an opportunity for our patients to get a cancer-prevention vaccine."

World Dental Congress (WDC) 2019, Presented September 6, 2019.

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