Incidence and clearance of oral human papillomavirus infection in men: the HIM cohort study.

BACKGROUND: Oral human papillomavirus (HPV) infection causes a subset of oropharyngeal cancers. These cancers disproportionately affect men, are increasing in incidence, and have no proven prevention methods. We aimed to establish the natural history of oral HPV infection in men.
METHODS: To estimate incidence and clearance of HPV infections, men residing in Brazil, Mexico, and the USA who were HIV negative and reported no history of anogenital cancer were recruited into the HPV Infection in Men (HIM) cohort study. A subset of the cohort who provided two or more oral rinse-and-gargle samples with valid HPV results and who completed a minimum of 2 weeks of follow-up were included in this analysis. Oral rinse-and-gargle samples and questionnaire data were obtained every 6 months for up to 4 years. Samples were analysed for the presence of oncogenic and non-oncogenic HPV infections by the linear array method.
FINDINGS: 1626 men aged 18-73 years and with a median follow-up of 12·7 months (IQR 12·1-14·7) were included in the analysis. During the first 12 months of follow-up, 4·4% (95% CI 3·5-5·6; n=115 incident infections) of men acquired an incident oral HPV infection, 1·7% (1·2-2·5; n=53 incident infections) an oral oncogenic HPV infection, and 0·6% (0·3-1·1; n=18 incident infections) an oral HPV 16 infection. Acquisition of oral oncogenic HPV was significantly associated with smoking and not being married or cohabiting, but was similar across countries, age groups, and reported sexual behaviours. Median duration of infection was 6·9 months (95 % CI 6·2-9·3; n=45 cleared infections) for any HPV, 6·3 months (6·0-9·9; n=18 cleared infections) for oncogenic HPV, and 7·3 months (6·0-not estimable; n=5 cleared infections) for HPV 16. Eight of the 18 incident oral HPV 16 infections persisted for two or more study visits.
INTERPRETATION: Newly acquired oral oncogenic HPV infections in healthy men were rare and most were cleared within 1 year. Additional studies into the natural history of HPV are needed to inform development of infection-related prevention efforts. FUNDING: US National Cancer Institute, Merck Sharp & Dohme.