The newest human papillomavirus vaccine, 9-Valent, can potentially prevent 80% of cervical cancers in the United States if given to all children at age 11 or 12 years, before they are exposed to the virus. These findings from a seven-center study were published in the Journal of the National Cancer Institute (2015; doi:10.1093/jnci/djv086).
In addition to protecting against 80% of cervical cancers, the new 9-Valent human papillomavirus vaccine has the potential to protect against approximately 19,000 other cancers diagnosed in the United States, including anal, oropharyngeal, and penile cancers. This is an 11.1% point increase in protection against HPV-related cancers in comparison to the first vaccines on the market, Gardasil and Cervarix.
This research effort was initiated by the Centers for Disease Control and Prevention in conjunction with Cedars-Sinai Medical Center in Los Angeles, California.
“This is the first comprehensive study of its kind and shows the potential to not only reduce the global cancer burden, but guide clinical decision-making with regard to childhood vaccinations,” said Marc T. Goodman, PhD, MPH, senior author of the study and director of Cancer Prevention and Genetics at the Cedars-Sinai Samuel Oschin Comprehensive Cancer Institute.
The study found the 9-Valent vaccine, under the trademark of Gardasil-9, also has the potential to protect against an additional 5.7% of oropharyngeal cancers, which include the base of the tongue and tonsils. This disease is the second-most-common HPV-associated cancer.
“We found that 70% of patient DNA tissue samples with cancer of the oropharynx harbored HPV,” added Goodman. “This is a much higher percentage of HPV than observed in other studies, likely because of changes in sexual behaviors, such as increased oral-genital contact.”
The 9-Valent vaccine was also found to potentially increase protection from other HPV-related cancers including those of the vulva, from 48.6% to 62.8%; vagina, from 55.1% to 73.3%; the penis, 47.9% to 56.9%; and the anus, 79.4% to 87.6%.
To compile these data, researchers examined 2,670 HPV DNA tissue samples from seven population-based cancer registries.
Study authors intend to perform additional research in the future to follow up on their estimate of how well the current vaccines protect against HPV-associated cancers.