Further Clinical Considerations Needed For Anal Cancer Screening in People Living with HIV

Recent anal cancer screening guideline developments for HIV patients have been an important step in prevention; however, these recommendations have left grey areas concerning the efficacy and cost-effectiveness of screening, according to a clinical review published in Clinical Infectious Diseases.

“The field of anal cancer prevention among people living with HIV is at an inflection point with promising early data and now delineated clinical guidelines,” the authors, including corresponding author Hayden S. Andrews, M.D., from the University of Texas Southwestern Medical Center, write in the review, published in July 2025. “While celebrating this progress, careful attention is needed for ongoing research evaluating its efficacy and increasing infrastructure to make high-resolution anoscopy implementation possible and equitable.”

Two clinical guidelines for anal cancer screening were published in 2024: the International Anal Neoplasia Society's (IANS’s) 2024 Consensus Guidelines and the U.S. Department of Health and Human Services (DHHS) Opportunistic Infections Human Papillomavirus (HPV) Panel.

Guidelines were informed by the Anal Cancer-HSIL Outcomes Research (ANCHOR) study, which showed that treating premalignant anal lesions decreased the subsequent risk of anal cancer among people living with HIV.

The IANS recommendation focuses on multiple risk groups, such as men who have sex with men and transgender women with HIV, while the DHHS recommendation only focuses on people living with HIV.

Both recommendations recommend routine screening of people living with HIV with an anal pap test and digital anorectal exam starting at age 35 for men who have sex with men, age 35 for transgender females, age 45 for all other men, and age 45 for women, according to the review.

There are approximately 10,000 anal cancer cases diagnosed annually in the United States, which makes anal cancer the 27^th most common cancer in the United States. The risk of anal cancer in people living with HIV can be up to 100-fold when compared with the general population.

Ninety percent of anal cancer cases are caused by high-risk HPV. It begins as anal dysplasia, of which there are two types: low-grade squamous intraepithelial lesion (LSIL) or high-grade squamous intraepithelial lesion (HSIL). HSIL is associated with high-risk HPV.

Until the results of the ANCOR study were released, previous guidelines only recommended anal cancer screening for patients engaging in anal sex, with genital warts, with cervical dysplasia and with access to high-resolution anoscopy.

In both recommendations, high-resolution anoscopy (HRA) is preferred over a simple anoscopy due to accuracy. However, HRA access is still limited in some areas due to the cost of equipment and the complexity of the procedure. For example, during an HRA, a clinician inserts an anoscope, examines the anus with a colposcope, stains the anus with acetic acid and Lugol’s iodine and removes suspicious lesions for biopsy. During a simple anoscopy, a clinician examines the anus with the naked eye and removes suspicious masses for biopsy.

“If HRA is unavailable, a screening anal pap test should not be done; instead, a patient can be asked about anorectal symptoms and have a digital anorectal exam with referral to an anorectal specialist for simple anoscopy if abnormal.”

Although there is currently no treatment to clear anal HPV infection, vaccination is encouraged.