Genital HPV prevalence remains high in men despite availability of vaccine
An estimated 34.8 million American men aged 18 to 59 years are infected with some form of genital HPV and one in four men have high-risk HPV, according to a National Health and Nutrition Examination Survey reported in JAMA Oncology.
However, HPV vaccination coverage was only 10.7% among vaccine-eligible men.
It is estimated that 9,000 cases of HPV–related cancers are diagnosed in men each year, resulting in 91% of anal, 72% of oropharyngeal and 63% of penile cancers. Based on the current trend, the annual incidence of HPV–related oropharyngeal cancers is expected to surpass the annual number of cervical cancers by 2020 despite the availability of a prophylactic vaccine against HPV.
“Previously, the importance of HPV vaccination was emphasized more in women because of HPV association with cervical cancer,” Jasmine J. Han, MD, from the department of obstetrics and gynecology at Womack Army Medical Center, told HemOnc Today. “However, the annual incidence of HPV–associated oropharyngeal (oral and throat) cancer surpassed cervical cancer incidence, which is more common in men. HPV vaccination in both men and women should be emphasized.”
The National Health and Nutrition Examination Survey is a series of ongoing cross-sectional surveys conducted by the National Center for Health Services of the CDC. Researchers recruited 1,868 men aged 18 to 59 years between 2013 and 2014. Of these men, 111 had inadequate laboratory samples and were excluded from the HPV infection analysis but retained for the self-reported vaccination rate.
“There was no study looking at prevalence of genital HPV infection among American men,” Han said. “Previously, oral HPV and sero-prevalence (antibody concentration in blood stream) were evaluated using this nationally well-known credible survey.”
During examinations, participants self-collected penile swab samples, which researchers then evaluated using polymerase chain reaction amplification to determine HPV genotyping.
The overall genital HPV infection prevalence for all men was 45.2% (95% CI, 41.3-49.3) — representing 34.8 million men — and the high-risk HPV prevalence was 25.1% (95% CI, 23-27.3).
Among men who were eligible to receive the HPV vaccine, the prevalence of infection with at least one HPV strain targeted by the HPV 4-valent vaccine was 7.1% (95% CI, 5.1-9.5), and the prevalence of an HPV strain targeted by the HPV 9-valent vaccine was 15.4% (95% CI, 11.7-19.6).
Additionally, single-strain infection occurred in a greater proportion of men with low-risk HPV than among men with high-risk HPV (79.1% vs. 36.4%).
Genital HPV infection prevalence was highest among non-Hispanic black men (65%; 95% CI, 59.7-70) and lowest among non-Hispanic Asian men (24.4%; 95% CI, 18.4-31.5).
The overall prevalence of HPV infection was lowest among men aged 18 to 22 years (28.9%; 95% CI, 22.2-36.8). Moreover, men in older age groups were approximately twice as likely to have genital HPV infection compared with those aged 18 to 22. Unmarried men were twice as likely to have genital HPV infections than married men.
“This was very interesting because the prevalence of genital HPV infection in men remained high among all age groups, which was a surprise because female HPV prevalence decreased as age increased,” Han said.
The overall HPV vaccination rate among eligible men was 10.7% (95% CI, 7.8-14.6).
Men aged 18 to 22 years were most likely to have been vaccinated (22%; 95% CI, 15.5-30.3) at a mean age of 17 years (95% CI, 16.4-17.8).
Researchers noted self-reported vaccination and sexual history can be considered limitations to the study because of potential under- or overreporting.
“The vaccination rate was only 10.7% among the eligible group,” Han said. “Public awareness of this high HPV prevalence in men is very important, especially with the current low rate of vaccination. In addition, further studies may be warranted to evaluate the rationale regarding the current male vaccination cutoff at age 26, which reflects the female guideline.” – by Chuck Gormley
Disclosure: Han and researchers report no relevant financial disclosures.