High-resolution anoscopy referral rates adopting different anal cancer screening strategies for men who have sex with men.

Abstract

The International Anal Neoplasia Society (IANS) has generated recommendations for anal cancer screening, identifying MSM living with HIV (MSM-LWH) ≥35 years and MSM-noHIV ≥45 years as groups to prioritize. Since high-resolution anoscopy (HRA) availability is still limited across Europe, a retrospective study was conducted to estimate the potential HRA referral rates of the STI/HIV center of a European capital city using IANS-recommended strategies. The study included participants in a program for the Surveillance of Anal Intraepithelial Neoplasia and anal HPV natural history (SAIN project). MSM-LWH ≥35 years and MSM-noHIV ≥45 years with valid results for liquid-based anal cytology and HPV test at baseline were included. The strategies evaluated were: cytology as a standalone test or with high-risk (hr)HPV triage; hrHPV (with/without HPV16 genotyping) as a standalone test or with cytology triage; co-testing with cytology and hrHPV (with/without HPV16 genotyping). Overall, 307 MSM were included (244 LWH, 79.5%). HrHPV as a standalone test led to the highest referral rate in both MSM-LWH and MSM-noHIV (74.6% and 55.6%, respectively). Cytology with hrHPV triage (without genotyping) and hrHPV with cytology triage resulted in the same referral rates (44.3% in MSM-LWH and 27.0% in MSM-noHIV). In settings with insufficient HRA capacity, only ASC-H/HSIL (4.9% and 9.5% for MSM-LWH and MSM-noHIV, respectively) and HPV16+ MSM (27% and 20.6%, respectively) would be referred to HRA. Adoption of IANS recommendations should balance the sensitivity of the screening algorithm and the HRA referral rate because the latter is a matter of concern in settings with limited HRA capacity.