- About one in five men over the age of 15 is infected with a high-risk HPV type.
- In men aged 9 to 26, those who received the 9-valent HPV vaccine had a lower risk of a combination of HPV-related cancers than those who were not vaccinated.
- The researchers said these results indicate that HPV vaccination should be gender-neutral.
The 9-valent human papillomavirus (HPV) vaccine was associated with a reduced risk of HPV-related cancer in adolescent males and young men, according to a large retrospective cohort study.
Among men aged 9 to 26 years who received the 9-valent HPV vaccine had a lower risk of HPV-related head and neck, penis, esophagus, and anal cancer compared with those who were not vaccinated (HR 0.54, 95% CI 0.37–0.81, P=0.002), Taito Kitano, DrPh, and Sayaka Yoshida, PhD, of Nara Prefecture General Medical Center in Japan, reported.
A subgroup analysis showed that those who were vaccinated had a significantly lower incidence of the primary composite outcome at 9 to 14 years of age (HR 0.58, 95% CI 0.34–0.97). P=0.04) and those aged 15 to 26 years (HR 0.50, 95% CI 0.27-0.93, P=0.03), he wrote JAMA Oncology.
Kitano and Yoshida said, “Given that current recommendations in developed countries advocate vaccinating all adolescent boys with (9-valent HPV vaccine), our study contributes to the growing body of evidence supporting these current practices.”
HPV infection is a major cause of cancer of the cervix, vagina, vulvar, anus, penis, and head and neck. About this one in five Men over the age of 15 are infected with high-risk HPV types. The American Academy of Pediatrics recommends Starting the HPV Vaccine Series In girls and boys ages 9 to 12, yet many teens do not get the HPV vaccination on time.
The authors concluded, “Our study suggests that (9-valent) HPV vaccines should be offered not only to women but also to young men.” “This study also contributes to gender-neutral HPV vaccination. Further studies are needed for long-term follow-up and catch-up vaccination in older adults.”
To assess the relationship between 9-valent HPV vaccination and HPV-related cancers in men aged 9 to 26 years, Kitano and Yoshida used records from the global TriNetX database. The study’s vaccinated group included people who had health screening and received at least one 9-valent HPV vaccine between January 2016 and December 2024. The unvaccinated group had a health checkup during that period but did not receive the HPV vaccination. Follow-up began 180 days after the health examination.
The researchers included 615,155 vaccinated men and 2,290,623 unvaccinated men. The mean age was 13.4 years and 17.2 years, and 48.2% and 8.7% were 11–12 years, respectively. In the vaccinated group, 20.2% were Black or African American and 55.0% were white, compared with 16.5% and 58.2% in the unvaccinated group.
After propensity score matching for age, race and underlying medical conditions, the investigators created vaccinated and unvaccinated groups of 510,260 participants each.
After matching, the primary composite outcome occurred in 40 participants in the vaccinated group and 64 participants in the non-vaccinated group. All cancers were of the head and neck, preventing secondary analyzes of esophageal, anal, and penile cancer risks.
In sensitivity analysis when extending the follow-up period to 2 years, the vaccination group was still in significant benefit for the primary composite outcome (HR 0.56, 95% CI 0.35–0.89). P=0.01).
Limitations of the study included reliance on ICD-10 coding alone for cancer diagnosis, which may have led to missed diagnoses. The study cohort included only adolescents who had undergone child health screening, which could introduce selection bias. The database also did not include information on HPV infection status; Not all cancers in the study were caused by HPV infection.
