Five-Year Evaluation of an Anal Cancer Screening Program in Men Who Have Sex With Men With HIV at 2 Academic Center Clinics.

BACKGROUND

Guidelines recommend annual anal cytology-based squamous cell carcinoma of anus (SCCA) screening for men who have sex with men with HIV aged ≥35 years (eligible population). The recommended threshold for high-resolution anoscopy (HRA) depends on its availability: low-threshold (any abnormal cytology) if availability is high and high-threshold (high-grade squamous intraepithelial lesion [HSIL] on cytology) if availability is low.

METHODS

This was a retrospective chart review (2018-2022) at academic HIV clinics. We evaluated (1) 5-year uptake of cytology-based SCCA screening in the eligible population and (2) estimated HSIL detection rate based on our current low-threshold criteria, and if high-threshold criteria were used for HRA referral.

RESULTS

Of 432 eligible individuals, only 219 (50.7%) had at least 1 and only 113 (26%) had >1 SCCA screening tests in a median follow-up of 4 years. Seventy-four (17.1%) individuals had at least 1 abnormal anal cytology during follow-up, of whom 56 (75.6%) underwent HRA. Increasing age (≥57 years) and history of smoking negatively correlated with ever receiving screening. Anal cytology (365 tests in 206 individuals) showed 17.5% "unsatisfactory" and 26.8% with any abnormal cytology (zero with HSIL) triggering HRA referral. Only 34 individuals (7.8% of screening eligible) were ever detected with HSIL. Strictly using high-threshold criteria for HRA referral would have led to no HRA or HSIL detection.

CONCLUSIONS

We noted poor uptake of screening over time, particularly in older age groups. Importantly, anal cytology performed poorly as a triage test for HRA referral, with high rates of "unsatisfactory" samples and low sensitivity for detecting HSIL.