Anal cancer screening results from 18-to-34-year-old men who have sex with men living with HIV

Men who have sex with men living with HIV (MSM LWH) are at highest risk for human papillomavirus (HPV)-associated anal cancer. There is no consensus on the optimal screening initiation age. This study aimed to assess the prevalence and severity of anal HPV disease among MSM LWH under the age of 35, which is a currently proposed screening age threshold. Between 2014 and 2020, 1255 18-to-34-year-old MSM LWH underwent anal cytology screening. 916 were co-tested for high-risk HPV (HR-HPV). 467 underwent high-resolution anoscopy (HRA) and biopsy. Cancer registry data were queried. Predictors of abnormal cytology (ie, ≥ASCUS) and histological high-grade squamous intraepithelial lesions (HSIL) were evaluated using unadjusted logistic regression models. Median age was 28 years (range, 18-34). 19% received at least one dose of HPV vaccine. Abnormal cytology rate was 65%. HR-HPV and HPV16 prevalence were 87% and 30%. Biopsy results were benign (10%), LSIL (43%) and HSIL (47%). No cases of prevalent or incident anal cancers were detected. Findings were similar between age subgroups (18-24, 25-29 and 30-34) except for a higher prevalence of AIN 3 in the 30-34 group (19%). Abnormal cytology was significantly associated with HR-HPV infection. Histological HSIL was associated with HR-HPV infection and cytological LSIL or worse. The absence of anal cancer in a large cohort of MSM LWH under the age of 35, despite high prevalence of anal HR-HPV infection and precancer, supports an age-based anal cancer screening strategy for MSM LWH.