The Risk of Anal Carcinoma After Anogenital Warts in Adults Living With HIV.

IMPORTANCE

In the US, incidence of and mortality due to anal carcinoma are rising faster than for most other cancers. Identifying populations who have a higher risk of developing anal cancers is critical to target preventive interventions.

OBJECTIVE

To assess the risk of developing anal carcinoma in adults living with HIV who have a history of anogenital warts.

DESIGN, SETTING, AND

PARTICIPANTS

This longitudinal cohort study included adults living with HIV from 14 clinics in Washington, DC, and at least 18 months of follow-up. Data were collected from January 1, 2011, to March 31, 2017, and analyzed from June 1, 2019, to October 31, 2020.

EXPOSURES: Development of warts in the anal or genital region identified by diagnosis codes.

MAIN OUTCOMES AND MEASURES: Individuals with anal carcinoma were identified by diagnosis codes or anal biopsy results.

RESULTS

A total of 6515 participants were enrolled (4720 male [72.4%] at birth; mean [SD] age, 49.9 [12.7] years), and 383 (5.9%) developed anogenital warts during the study period. Patients who were diagnosed with anogenital warts were more likely to subsequently develop anal carcinoma (17 of 383 [4.4%]) compared with participants without a history of anogenital warts (17 of 6132 [0.3%]) (P < .001). After adjusting for covariates, the odds of developing anal carcinoma were 12.79 (95% CI, 6.19-26.45; P < .001) times higher in individuals with a history of anogenital warts compared with individuals without a history of anogenital warts.

CONCLUSIONS AND RELEVANCE: These findings suggest that adults living with HIV who have a history of anogenital warts have a substantially increased risk of developing anal carcinoma. Clinicians should counsel individuals living with HIV who have anogenital warts on this risk.