History of Anogenital Warts Increases Risk of Anal Carcinoma in Adults With HIV

January 13, 2021
Killian Meara

Anal squamous cell carcinoma mortality rate is rising faster than other types of cancer in the United States.

The majority of sexually active individuals have been exposed to the human papillomavirus (HPV), but the infections are usually brief. However, in some cases they can be persistent and infection with a high-risk type of HPV can result in anogenital squamous cell carcinomas. Some risk factors have been associated, including immunosuppression, receptive anal intercourse, men who have sex with men (MSM), smoking, and Human Immunodeficiency Virus (HIV).

Recent data published in the journal Jama Dermatology, shows that adults living with HIV, who also have a history of anogenital warts, have a substantially increased risk of developing anal carcinoma.

Investigators analyzed longitudinal cohort data and assessed the degree of association between warts of the anogenital region and anal carcinoma. The study included 6,515 participants who were taken from the District of Columbia’s Cohort Longitudinal HIV Study and had at least 18 months of follow up. They were classified as having a history of anogenital warts, with additional variables abstracted including age, race and ethnicity, sex at birth, duration living with HIV, HIV transmission risk factor and Tabaco use.

Findings from the study demonstrated that of the participants, 383 (5.9%) were diagnosed with anogenital warts within the study period. These individuals were more likely to be male, between the ages of 18-34 years of age and be MSM. There was no statistically significant difference found between race and ethnicity, years living with HIV or smoking history.

Those without a history of anogenital warts were enrolled for a median of 4.1 years, while those with a history were enrolled for a median of 4.7 years. 17 (4.4%) of the participants with a history eventually developed anal carcinoma, in comparison to 17 (0.3%) of those without. Once the investigators adjusted for covariates, they found that those with a history of anogenital warts were 12.79 times higher to develop anal carcinoma than those without.

“These results emphasize the importance of counseling populations living with HIV with anogenital warts on their elevated likelihood for developing anal cancer,” the authors wrote. “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.”