Development and uptake of the human papilloma virus (HPV) vaccine has been crucial in reducing rates of virus-linked cervical cancers in women.
Now, the accumulated data suggests the vaccine is saving men from fatal cancers, too.
Overall, men who got the vaccine [typically as boys] saw their odds for HPV-linked cancers slashed in half, according to a report to be presented at the upcoming meeting of the American Society of Clinical Oncology (ASCO) in June.
Tumors in men known to be related to HPV infection include cancers of the head and neck, anal areas and penis. The overall rate of such cancers among vaccinated men was 7.5 cases per 100,000 men, but that rate fell to 3.4 among men who'd been vaccinated, the report found.
The biggest declines were seen in the prevention of male head and neck cancers -- 2.8 cases per 100,000 vaccinated patients vs. 6.3 per 100,000 unvaccinated patients.
"We have known the HPV vaccine decreases rates of oral HPV infection, but this study shows that in boys and men in particular, vaccination decreases the risk of HPV-related oropharyngeal head and neck cancers," said Dr. Glenn Hanna, who wasn't involved in the new research.
"HPV vaccination is cancer prevention," Hanna said in an ASCO news release. He directs the Center for Cancer Therapeutic Innovation, part of the Center for Head and Neck Oncology at the Dana-Farber Cancer Institute in Boston.
Current guidelines from the U.S. Centers for Disease Control and Prevention advise that all children be routinely vaccinated against HPV at age 11 or 12, although vaccination can be done as early as age 9.
HPV is transmitted via sexual contact, so the reasoning is that people get vaccinated before the onset of sexual activity.
With HPV responsible for the vast majority of cervical cancers, the focus of vaccination has long been girls. But experts have known that boys and men can be also affected by HPV-linked cancers of the mouth, throat, head/neck, anus and penis as they age.
The new research was led by Jefferson DeKloe, a research fellow at Thomas Jefferson University in Philadelphia. His team tracked rates of HPV-related cancers in about 5.5 million Americans, about 949,000 of who had been vaccinated against HPV.
Besides the encouraging findings in men, the study also affirmed that vaccination cut women's odds for HPV-related cancers.
For example, women's rate of cervical cancers fell from 10.4 per 100,000 unvaccinated patients to 7.4 cases per 100,000 vaccinated patients, the study found. They also had a lower rate for all HPV-linked cancers combined: 15.8 per 100,000 unvaccinated patients vs. 11.5 cases per 100,000 vaccinated patients.
For reasons that aren't clear, women received no benefit from vaccination in terms of head and neck cancer incidence, unlike the trend seen among men.
Still, the benefits of vaccination for women and men are obvious, DeKloe said.
"This study adds to a growing body of evidence demonstrating decreased rates of HPV-related cancer among people who received the HPV vaccination," he said.
Unfortunately, immunization rates remain too low.
"The CDC reported that in 2022, less than 60% of children ages 15-17 had been vaccinated for HPV, suggesting that a large portion of the population is more vulnerable to HPV infection and, in turn, more vulnerable to the development of HPV-related cancers," DeKloe noted. "Identifying effective interventions that increase HPV vaccination rates is critical in reducing undue cancer burden in the United States."
There is some reason for hope: A second study to be presented at the ASCO meeting shows rates of HPV vaccination steadily increasing among American adolescents.
Looking at data between 2011 and 2020, a team led by Jacqueline Nguyen of MD Anderson Cancer Center in Houston found that adolescent HPV vaccination uptake rose by about 20% overall (23.3% to 43.0%) and across all racial and ethnic groups.
The rise in immunization was sharpest among boys, rising from 7.8% to 36.4%, the study found. Still, that number remains significantly below the 49.4% vaccination rate achieved by girls and women in 2020, Nguyen's team noted.
The findings from these two studies should be considered preliminary until published in a peer-reviewed journal.
More information
The full recommendations on HPV vaccination can be found at the American Cancer Society.
SOURCE: American Society of Clinical Oncology, news release, May 23, 2024