Approximately 50% of men from a general population sample tested positive for HPV, and each year an estimated 6% are expected to acquire an infection with the most common cancer causing strain, HPV 16.
Anna R. Giuliano, PhD, chair of the department of Cancer Epidemiology and Genetics at the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., and colleagues published results from the HPV in Men (HIM) Study online this week in Lancet.
“The results from this study provide much needed data about the incidence and clearance of HPV infection in men; these data are essential for the development of realistic cost-effectiveness models for male HPV vaccination
internationally,” the researchers wrote.
They analyzed HPV incidence and clearance among a cohort of 1,159 men aged 18 to 70 years from Brazil, Mexico and the United States, who did not have HIV or a history of cancer. Men were tested for HPV every six months for more than two years on average.
The researchers found that men who had a higher number of lifetime female (≥50 vs. ≤1 partners, HR=2.40, 95% CI: 1.38-4.18) or male anal sexual partners (≥3 vs. no recent partner in previous 3 months, HR=2.57, 95% CI: 1.46-4.49) were more likely to have had an oncogenic HPV infection. Data revealed that men in Brazil had the highest incidence of both oncogenic (P=0.0109) and nononcogenic HPV types (P<0.0001) at 12 months, but risk for HPV 16 was highest in Mexico (P=0.0195).
HPV duration was longer for the oncogenic type HPV 16 vs. other types (12-19 months for HPV 16 vs. 7.52 months), regardless of age, data indicated. Median time to clearance for any other HPV type was significantly longer in men aged 18 to 30 years compared with older men. “The more rapid clearance noted in older men might be related to a higher prevalence of HPV antibodies in older men,” the researchers wrote.
Previous results from study involving women have indicated that the risk for HPV decreases with age; however, risk remained constant regardless of age among HIM study participants. Although no evidence exists to explain the lack of an association between disease risks and age in men, the researchers pointed out the number of sexual partners was similar for all age groups in the HIM cohort.
They also suggested that HPV immune responses might be different in men and women, citing lower HPV antibody titers despite higher genital HPV DNA prevalence.
“The HIM data on HPV incidence and clearance should be exploited to elaborate prevention guidance and to minimize transmission and aid management and associated concerns for couples,” Joseph Monsonego, MD, of the department of colposcopy at the Institute of the Cervix in Paris, wrote in an accompanying editorial.
Monsonego pointed out that condoms do not fully protect against HPV transmission, at best preventing about 70% of new HPV and cervical intraepithelial neoplasia. Additionally, men are often asymptomatic and therefore unaware of the need to use condoms.
“Although we will continue to encourage protective measures, condom use and safe sex practices are of little value in clinical practice — prevention of HPV transmission and its consequences remain unconfirmed,” Monsonego wrote. “HPV vaccination of men will protect not only them but will also have implications for their sexual partners.”