Multiple studies show major lack of public knowledge about HPV vaccine and cancer prevention

Despite the fact that the human papillomavirus (HPV) vaccine has been available in the U.S. for over 10 years and remains the only vaccine to protect against multiple types of cancer, several recent studies show that public knowledge about the vaccine and HPV’s relationship to cancer remains low.

HPV is responsible for 90% of cervical and anal cancers, and 70% of oropharyngeal (throat) cancers.

The first-generation HPV vaccine was approved by the FDA in 2006. It protected against four strains of the virus. In 2014, the second-generation HPV vaccine was introduced. It protects against nine of the most common cancer-causing forms of the virus and is most effective when given at ages 11-12.   

Limited knowledge about cancers caused by HPV

According to a study published in JAMA Pediatrics in September, 70% of U.S. adults did not know that HPV causes oral, anal and penile cancers. HPV-related oral cancers in men have been on the rise in recent years, and now outnumber cervical cancer cases, underscoring the importance of HPV vaccination for boys, as well as girls.

Additionally, the study found 60.1% of U.S. men and 31.6% of women aged 18 to 26 did not know HPV causes cervical cancer. MD Anderson’s Kathleen Schmeler, M.D., professor of Gynecologic Oncology and Reproductive Medicine, was a co-author on the study led by colleagues at UTHealth. The study examined publically available data from the Health Information National Trend Survey (HINTS).

“The lack of knowledge in adults, especially ages 27 and older, is concerning because they’re likely to be parents,” Schmeler says. “If the people in that age group don’t realize HPV causes cancer, they may be less likely to get their kids vaccinated.”

Limited knowledge about vaccine’s effectiveness in cancer prevention

Sanjay Shete, Ph.D., professor of Biostatistics and Epidemiology and deputy division head of Cancer Prevention and Population Sciences at MD Anderson, also looked at the nationally representative HINTS data to assess women’s beliefs about the HPV vaccine’s success in cervical cancer prevention. That study, published in August in JNCI Cancer Spectrum, found that 63.6% of U.S. women aged 18 and older did not know if the HPV vaccine is successful in preventing cervical cancer and 6.6% believed that it was not successful.  

“We wanted to look at beliefs about the vaccine’s effectiveness because it’s a strong predictor of intent to vaccinate,” Shete says. “Unfortunately, we found that the vast majority of women either didn’t know whether or not the HPV vaccine prevented cervical cancer or believed that it didn’t.”

Limited knowledge even among HPV-related cancer survivors

A third study, also led by MD Anderson and published in Supportive Care in Cancer in August, examined HPV knowledge among those personally affected: survivors of HPV-related cancers. The research team, led by Lois Ramondetta, M.D., professor of Gynecologic Oncology and Reproductive Medicine, and Zeena Shelal, M.D., clinical studies supervisor in Palliative, Rehabilitation & Integrative Medicine, surveyed 200 MD Anderson patients and volunteers who’d had HPV-related cancers.

Only 33.2% of respondents reported knowing that their own cancer was HPV-related and 56.8% reported knowing that the HPV vaccine is safe.

“We were in a little bit of shock about how few patients really understood their cancer was related to HPV,” Ramondetta says. “We’re missing an opportunity to educate patients and survivors.”

The research team surveyed MD Anderson patients and volunteers with common HPV-related cancers; HPV infection could not be confirmed via chart review for the volunteers or for a small number of patients.  

The study also found that people who knew that their cancer was caused by HPV were more likely to have vaccinated their children. Those who knew the vaccine was safe were more willing to recommend the vaccine and to act as an advocate for HPV vaccination or as a peer mentor for others with HPV-related cancers.

A call to action for providers

Based on these results, the authors suggest one simple step toward addressing the HPV knowledge gap is for oncologists to educate their patients about the HPV vaccine and its ability to safely prevent cancer.

“Tell your patients if HPV caused their cancer and explain that they could protect their kids by making sure their children get the HPV vaccine,” Ramondetta says. “We can change the culture and we need to empower patients to do so as well.”