The HPV vaccine is linked to a drastic reduction in head and neck cancers in adolescent boys and men, new research finds.
HPV, or human papillomavirus, is a sexually transmitted infection responsible for virtually all cases of cervical cancer. But the virus is also linked to a number of other cancers, including penile, anal and vaginal cancers.
It also accounts for the majority — up to 70% — of head and neck cancers, which affect the throat and mouth. Men are about twice as likely to develop these cancers than women, according to the National Cancer Institute.
The HPV vaccine, initially approved for adolescent girls, protects against strains of the virus linked to cervical cancer and has been found to significantly reduce rates of the cancer. But there’s growing evidence that the vaccine also protects against other HPV-related cancers.
“We want males to be thinking about HPV vaccination not just as something that protects female patients, but also male patients,” said Jefferson DeKloe, a research fellow in the department of otolaryngology at Thomas Jefferson University, who specializes in head and neck surgery and who co-authored the research.
The findings will be presented next week at the American Society of Clinical Oncology conference and have not yet been published in a peer-reviewed journal.
Prior research showed a downward trend in oral infections with HPV strains known to cause cancer. That was a promising sign, said Dr. Glenn J. Hanna, a medical oncologist at the Dana-Farber Cancer Institute’s Center for Head and Neck Oncology, who was not involved in the new research.
“If we can lower the infection rate, we would hope that we would see what we are seeing now, a decline in cancer rates,” Hanna said. “This is an important evolution of the story.”
The new study analyzed health records from a national database that included nearly 3.5 million people in the United States ages 9 to 39 who had received any vaccination — HPV or otherwise — from 2010 through 2023. About 1.5 million were male, half of whom had been vaccinated against cancer-causing strains of HPV. Nearly 1 million were females who had been vaccinated against HPV.
The researchers compared the rates of HPV-linked cancers — including head and neck, anal, penile, and cervical cancers — in people who had received the HPV vaccine to those who hadn’t. They found being vaccinated reduced the overall risk of HPV-related cancers in males by 54%, a decrease driven primarily by a drop in head and neck cancers. Females were about 30% less likely to develop any type of HPV-related cancer, including cervical cancer.
Most cases of head and neck cancer are in people older than 50. Since the U.S. is only about a decade into widespread HPV vaccination in both males and females, the vaccinated generation hasn’t reached this age yet. HPV typically infects younger people and takes decades for chronic infection to lead to cancer.
“These are the early results of a larger phenomenon we are going to watch play out over the next 20 or 30 years,” DeKloe said, noting that experts don’t expect to see the full effect HPV vaccination has on cancer rates until the largely vaccinated generation is older.
A second study, which will also be presented at the ASCO conference next week and is not yet published in a peer-reviewed journal, found that HPV vaccination rates have been on the rise in the U.S. from 2011 through early 2020, including in all racial and ethnic groups.
HPV vaccination wasn’t recommended for males until 2011, five years after the Centers for Disease Control and Prevention recommended the vaccine series for girls. The HPV vaccine is now recommended for all adolescents starting as young as age 9, but can also be given to adults up to age 45.
In the new study, which included children and young adults ages 9 to 26, the increase was largely driven by growing HPV vaccine uptake among males. Although overall HPV vaccination rates among males still lag behind females — about 36% compared to about 50% of those in the 9 to 26 age group — these rates are accelerating.
“The gap is narrowing between males and females and eventually I would hope that they would meet up,” said Dr. Danh Nguyen, a resident physician at University of Texas Southwestern Medical Center, who led the research.
Although vaccination efforts have focused on adolescents, adults should also consider getting vaccinated if they weren’t when they were younger, said Dr. Nancy Lee, service chief of head and neck radiation oncology at Memorial Sloan Kettering Cancer Center in New York City, who was not involved with either study.
“If you are in your 20s or 30s, you can still get the vaccination. Even if you are 45, there is no reason you cannot get vaccinated because we have a population that lives a long time,” Lee said.
Nguyen said it’s important that conversations about HPV vaccination continue to focus on the prevention of all cancers, including head and neck cancers that are more prevalent in men, rather than solely on cervical cancer prevention.
Hanna said stigma around HPV being a sexually transmitted infection has made discussions around vaccinating adolescents a sticky subject in the past, but that clear data showing the impact vaccination rates have on HPV-related cancers is shifting the narrative.
“HPV vaccination is cancer prevention,” Hanna said. “The bottom line is that we are preventing cancers broadly by getting people vaccinated younger.”
