Comparable anal HPV burden and abnormal cytology in MSM using PrEP and MSM living with HIV: implications for...

Men who have sex with men using pre-exposure prophylaxis (MSM-PrEP) represent an emerging population at high risk for anal human papillomavirus (HPV)-related disease. However, screening strategies and evidence have primarily focused on MSM living with HIV. We compared the burden of high-risk anal HPV (HR-HPV) infection, abnormal cytology and associated risk factors between MSM using PrEP and MSM living with HIV.

In this cross-sectional study, MSM attending a Belgian HIV/PrEP clinic between 2020 and 2023 were recruited. A total of 303 participants were enrolled; 298 had analysable HPV and/or cytology results (148 MSM-PrEP and 150 MSM living with HIV). Participants completed a questionnaire, and anal swabs were collected for cytology and HPV genotyping. Multivariable logistic regression was used to identify factors associated with HR-HPV infection and abnormal cytology.

HR-HPV was detected in 74.3% of MSM-PrEP and 75.8% of MSM living with HIV (p=0.79). Abnormal cytology (≥atypical squamous cells of undetermined significance) was present in 53.5% and 56.8%, respectively (p=0.66). Chemsex was independently associated with a higher likelihood of HR-HPV infection (adjusted OR 2.67; 95% CI 1.25 to 5.70). HPV vaccination initiated after sexual debut was associated with a lower prevalence of HR-HPV (adjusted OR 0.37; 95% CI 0.16 to 0.82), although this analysis was exploratory.

MSM using PrEP showed a burden of HR-HPV infection and abnormal anal cytology comparable to that observed in MSM living with HIV. These findings suggest that MSM-PrEP constitutes a high-risk group that may warrant reconsideration of current anal cancer screening strategies. The potential protective effect of postsexual-debut HPV vaccination merits further investigation.