HPV vaccination may lower risk of oral infections that cause mouth cancer
CHICAGO, USA: A study conducted in the U.S. has found that the human papillomavirus (HPV) vaccine may help reduce oral infections that cause mouth and throat cancer by as much as 88 percent. However, the actual impact of the vaccine on oral HPV infections remains low, owing to the poor rate of uptake in the country, especially in males. The research is the first large study to explore the possible impact of the vaccine on oral HPV infections.
The research is the first large study of its kind, to explore the possible impact of the vaccine on oral HPV infections. Senior study author Prof. Maura Gillison, from the University of Texas MD Anderson Cancer Center, said that, despite rates of HPV-caused oral cancers continuing to rise every year in the U.S., particularly among men, no clinical trial had evaluated the potential use of the HPV vaccine for the prevention of oral HPV infections that could lead to cancer. “Given the absence of gold-standard, clinical trial data, we investigated whether HPV vaccine has had an impact on oral HPV infections among young adults in America.”
Using data from the National Health and Nutrition Examination Survey, the study looked at self-reported records of 2,627 young adults, aged 18–33, during the period 2011–2014 and compared those who had received one or more doses of an HPV vaccine with those who had not. Focusing on the prevalence of HPV16, 18, 6 and 11—the four types covered by HPV vaccines prior to 2016—oral rinse samples collected by mobile health facilities were tested for the virus in Gillison’s lab.
According to the results, the HPV strains investigated were found in far fewer people who had received vaccine shots, demonstrating an 88 percent lower risk. At the time of data collection, around 18.3 percent of young adults in the U.S. reported receiving one or more vaccine doses before age 26, with vaccinations more common in women than men (29.2 vs. 6.9 percent).
“When we compared the prevalence in vaccinated men to non-vaccinated men, we didn’t detect any infections in vaccinated men. The data suggests that the vaccine may be reducing the prevalence of those infections by as much as 100 percent,” said Gillison.
Approved in 2006 to prevent cervical cancers in women, and later for other cancers, including anal cancer in men, negative stigma around the HPV vaccine being used only to prevent sexually transmitted infections and not cancer has meant gaining acceptance and awareness has been slow. Actor Michael Douglas raised the issue publicly several years ago, when he blamed his cancer on it.
Oral sex has been regarded as the main risk factor for contracting an HPV infection in the mouth or throat, according to Gillison. She explained, however, that oral sex does not give one cancer. The infection in rare cases can develop into cancer over many years.
According to the Centers for Disease Control and Prevention, 63 percent of adolescent girls and 50 percent of adolescent boys have started with the HPV vaccine series throughout the U.S. Nation-wide, there are an estimated 3,200 new cases of HPV-associated oropharyngeal cancers diagnosed in women and about 13,200 diagnosed in men each year.
The study results, under the abstract title of “Impact of prophylactic human papillomavirus (HPV) vaccination on oral HPV infections among young adults in the U.S.,” will be presented at the American Society of Clinical Oncology’s 2017 annual meeting, which is taking place from June 2 to 6 in Chicago. The study received funding from the National Institute of Dental and Craniofacial Research of the National Institutes of Health.