Evaluation of anal cancer screening practices among a national cohort of Veterans with HIV

Abstract: BACKGROUND: When available, anal cytology is used for initial anal cancer screening, whereas diagnostic histology is typically performed after abnormal cytology or in symptomatic individuals. OBJECTIVE: Analyze index anal evaluations (cytology vs histology) in veterans with HIV. DESIGN: Retrospective cohort study. SETTINGS: One hundred thirty Department of Veterans Affairs medical centers. PATIENTS: Veterans with HIV who received care from 1999 to 2023. MAIN OUTCOME MEASURES: Distribution of index anal evaluations as cytology or histology, annual incidence rates of index evaluations, and regional anal cancer prevalence and screening rates. RESULTS: Among 48,368 veterans with HIV, 7127 (15%) had at least 1 anal evaluation. Index evaluations were cytology in 4477 (63%) and histology in 2650 (37%). The mean annual rate of index anal evaluations was 1.04%, with a relative decrease in 2020 and beyond. Among patients with anal evaluations, the Pacific region had the highest proportion of index cytology (77%), comprising 77% of evaluations, and the Continental region had the lowest (37%, p < 0.001). Conversely, the lowest and highest rates of anal cancer were observed in the Pacific and Continental regions, respectively (4.7% vs 9.4%, p < 0.001). However, this trend did not translate into differences in anal cancer rates between the 2 regions when comparing all veterans with HIV (1.01% vs 0.90%, p = 0.52). LIMITATIONS: Retrospective data. CONCLUSIONS: In this national analysis of veterans with HIV, only 15% had an anal evaluation, despite recommendations for annual screening. The majority of index evaluations were screening assessments with cytology (63%). There was a relative decrease in index evaluations after 2020. Regional screening differences were observed among patients with anal evaluations. Higher anal cancer detection was seen in the region with the lowest screening and lower detection in the region with the highest screening. Interestingly, this correlation did not persist when examining the overall regional populations of veterans with HIV, including those never evaluated.