Anal cancer is caused by human papillomavirus (HPV), particularly HPV-16, and is preceded by anal high-grade squamous intraepithelial lesions (HSILs). The incidence of anal cancer is highest among men who have sex with men (MSM) living with HIV (MSMLWH) and increases with age. However, most previous studies of anal HPV infection and anal HSIL were performed on men under 50 years old, and relatively little is known about HSIL among older MSMLWH or MSM not living with HIV (MSM-Not-LWH).
One hundred twenty-nine MSMLWH and 109 MSM-not-LWH participated. All participants had anal HPV DNA testing (Atila Biosystems) and high-resolution anoscopy with a biopsy of visible lesions.
Among MSMLWH, 47% had anal HSIL, 19% had HPV-16, and 51% had other oncogenic anal HPV types (excluding HPV-16). Among MSM-not-LWH, 37% had anal HSIL, 22% had HPV-16, and 34% had other oncogenic anal HPV types. Increasing age was not statistically associated with prevalent HSIL, HPV-16, or other oncogenic HPV infections in MSMLWH or MSM-not-LWH. HPV-16 (odds ratio: 45.1, 95% confidence interval: 15.8–129); other oncogenic HPV types (odds ratio: 5.95, 95% confidence interval: 2.74–12.9) were associated with increased odds of anal HSIL, adjusted for age, income, education, and HIV status.