Sex Differences in Risk Factors and Natural History of Oral Human Papillomavirus Infection.

UNLABELLED: Oral human papillomavirus genotype 16 (HPV16) infection causes oropharyngeal squamous cell carcinoma (SCC), and the prevalence of oropharyngeal SCC is higher among men than women in the United States. In a cohort study of oral HPV infection among 409 individuals aged 18-25 years, the risk among men but not among women significantly increased as the number of recent (ie, within the prior 3 months) oral sex partners increased (Pinteraction = .05). In contrast, the risk among women but not among men significantly decreased as the lifetime number of vaginal sex partners increased (Pinteraction = .037). Men were also significantly less likely than women to clear oral HPV infection. Our data contribute to understanding sex differences in risk for HPV-positive oropharyngeal SCC. CLINICAL TRIALS REGISTRATION: NCT00994019.