History of Anogenital Warts and HIV Puts Patients at Higher Risk for Anal Carcinoma

Adults with HIV who have a history of anogenital warts have a substantially increased risk for developing anal carcinoma, researchers reported in JAMA Dermatology.

The longitudinal cohort study included adults with HIV from 14 clinics in Washington, DC, who had 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. Patients with anal carcinoma were identified according to diagnosis codes or anal biopsy results.

Among 6515 participants (4720 men [72.4%] at birth; mean [SD] age, 49.9 [12.7] years), 383 (5.9%) were diagnosed with anogenital warts during the study period. Compared with 6132 participants without anogenital warts, the patients with anogenital warts were more likely to be men (311 [81.2%] vs 4409 [71.9%]) and younger (18-34 years, 98 [25.6%] vs 812 [13.2%]), have a CD4 level nadir of less than 200/μL (223 [58.2%] vs 2410 [39.3%]), and be men who have sex with men (207 [54.0%] vs 2246 [36.6%]).

Patients who were diagnosed with anogenital warts were more likely to develop anal carcinoma (17 of 383 [4.4%]), compared with those without a history of anogenital warts (17 of 6312 [0.3%]; P <.001). After adjusting for covariates, the study authors found that the odds of developing anal carcinoma were 12.79 (95% CI, 6.19-26.45; P <.001) times higher in participants with a history of anogenital warts compared with those without a history of anogenital warts.

“Persons living with HIV with a history of anogenital warts have a substantially increased risk of developing anal carcinoma compared with persons living with HIV without a history of anogenital warts,” stated the investigators. “Our findings highlight the importance of counseling individuals living with HIV who have warts of the anogenital region — especially those with longstanding HIV infections or a history of CD4 level nadir of less than 200/μL — about their increased risk for anal neoplasia. It is still unclear, however, whether they may benefit from digital anorectal examinations, anal Papanicolaou tests, or high-resolution anoscopy (analogous to a colposcopy) in the case of abnormal findings to screen for anal neoplasia.”

The most significant study limitation, according to the researchers, is the possibility of surveillance bias because patients were not systematically screened for anogenital warts or anal cancer, as these evaluations were at the study clinicians’ discretion.

“Further research is necessary to more clearly identify risk factors for anal neoplasia in women living without HIV — who represent a group increasingly affected by anal carcinoma — to allow targeted counseling and screening in this population,” the study authors commented.

Reference

Arnold JD, Byrne ME, Monroe AK, Abbott SE; for the District of Columbia Cohort Executive Committee. The risk of anal carcinoma after anogenital warts in adults living with HIV. JAMA Dermatol. Published online January 13, 2021. doi: 10.1001/jamadermatol.2020.5252