Introduction
Persistent high-risk Human Papillomavirus (HR-HPV) infection can lead to an anal high-grade squamous intraepithelial lesion (HSIL), the precursor lesion to anal squamous cell carcinoma (SCC).
HR-HPV prevalence is higher in men who have sex with men living with HIV (MSMLWH) than in HIV-negative MSM, respectively 74% and 37-41% (1,2). The use of Pre-Exposure Prophylaxis (PrEP) in HIV-negative MSM to prevent HIV contraction created a new Sexual Minority Group among MSM, i.e. MSM using PrEP. The aim of this study was to determine the prevalence of anal HR-HPV infection and abnormal anal cytohistology in MSM using PrEP and MSMLWH. Preliminary data are reported here and final results are expected in coming months.
Aims & Methods
MSM using PrEP and MSMLWH were enrolled in this mono-centric study during consultations at the S-clinic and the HIV-reference centre respectively. Patient characteristics, sexual behavior and demographics were collected using a questionnaire, completed on the day of the anal swab testing. Patients with HR-HPV infection, abnormal cytology or both were subsequently sent for High Resolution Anoscopy (HRA).
Results
At present, we enrolled 150 MSM using PrEP and 107 MSMLWH. Quality of anal swabs was sufficient in respectively 95% (n=143) and 81% (n=87). HR-HPV prevalence in MSM using PrEP was comparable with HR-HPV prevalence in MSMLWH; respectively 74% (n=106) and 75% (n=65) tested positive for at least one HR-HPV (p=1.000). No significant difference in abnormal cytology was seen; 53% (n=76) of MSM using PrEP and 58% (n=51) of MSMLWH had either ASC-US, ASC-H, LSIL or HSIL (p=0.6). Until today, 58 MSM using PrEP and 31 MSMLWH underwent HRA. Biopsies were performed in 43 MSM using PrEP and 25 MSMLWH. Preliminary results on histology of lesions show presence of anal HSIL in 19% (n=11) and 32% (n=10) respectively (p= 0.706).
Conclusion
MSM using PrEP have a similar risk of HR-HPV infection and abnormal anal cytohistology as MSMLWH, which is higher than what has been reported in HIV-negative MSM not using PrEP (1). ANCHOR showed that treating anal HSIL reduces the incidence of anal SCC in people living with HIV (3), but the risk of progression to anal cancer and thus the need for screening and treatment is to be investigated in this immunocompetent population of MSM using PrEP.
References
1. Wei F, Gaisa M, Gypsyamber D et al. Epidemiology of anal human papillomavirus infection and high-grade squamous intraepithelial lesions in 29 900 men according to HIV status, sexuality, and age: a collaborative pooled analysis of 64 studies. Lancet HIV. 2021;8(9):531-43.
2. Machalek D, Poynten M, Jin F et al. Anal human papillomavirus infection and associated neoplastic lesions in men who have sex with men: a systematic review and meta-analysis. Lancet Oncol. 2012;13(5):487-500.
3. Palefsky J, Lee J, Jay N et al. Treatment of Anal High-Grade Squamous Intraepithelial Lesions to Prevent Anal Cancer. N Engl J Med. 202;386(24):2273-82.
