Anal cancer incidence among Medicaid enrollees with HIV in the United States.

e16479 Background: Anal cancer incidence remains elevated among people with HIV (PWH); however, incidence among PWH enrolled in Medicaid, particularly across U.S. geographic regions, remains poorly characterized. Approximately 40% of U.S. adults with HIV under age 65 are enrolled in Medicaid, and anal cancer screening was formally recommended for PWH by the U.S. Department of Health and Human Services in 2024. Characterizing anal cancer incidence in this population is therefore a critical public health and cancer prevention priority. Methods: We used the National Medicaid Database to estimate anal cancer incidence among PWH from 2016–2020. Anal cancer (ICD-10 C21) and HIV diagnoses (B20–B24, Z21, R75, B97.35) were identified using claims data. Individuals with < 12 months of Medicaid enrollment, dual Medicare–Medicaid eligibility, or anal cancer diagnosed prior to HIV diagnosis were excluded. Absolute incidence rates (per 100,000 person-years) were estimated nationally and by region, state, and county, restricting geographic estimates to areas with ≥10 cases. Sex-stratified incidence rates were estimated at national and regional levels. Results: Between 2016–2020, 1,047 anal cancer cases (246 females, 801 males) were diagnosed among 611,305 PWH. Overall anal cancer incidence was 52.7 per 100,000 person-years, with substantially higher incidence among males (68.7 per 100,000) than females (30.0 per 100,000). Marked regional variation was observed among males, with the highest incidence (per 100,000) in the Midwest (97.2) and South (94.7) and the lowest in the Northeast (54.6) and West (55.4). Among females, incidence rates were comparable in the Midwest (26.9), Northeast (27.6), and West (24.1), but were relatively higher in the South (40.2). At the state level, Missouri had the highest incidence (122.0), followed by Georgia (112.2) and Ohio (94.7), whereas New York (37.2) and New Jersey (42.3) had the lowest incidence in the nation. At the county level, the lowest incidence was observed in New York State counties—Queens (28.0), Kings (35.6), Bronx (46.9), and New York County (49.6)—as well as Los Angeles County (47.5). Conclusions: Anal cancer screening has been recommended in New York State since the mid-2000s under guidelines issued by the New York State Department of Health AIDS Institute. The consistently lower anal cancer incidence among PWH in New York and New Jersey, particularly within New York counties, may suggest a potential population-level benefit of early and sustained screening efforts. This study also demonstrates substantial geographic disparities, with the highest incidence rates observed in the Midwest and South, underscoring the importance of targeted prevention efforts in these regions.