German-Austrian guideline on screening for anal dysplasia and anal carcinoma in people living with HIV.

People with HIV are up to 100 times more likely to develop anal carcinoma compared to the general population. Diagnosing and treating precursor lesions, specifically high-grade anal dysplasia, can significantly reduce the risk of developing anal carcinoma. This S2k-guideline outlines the factors that increase the likelihood of developing anal carcinoma and its precursors, including advancing age, a low CD4⁺ T-lymphocyte nadir, active cigarette smoking, receptive anal intercourse, or persistent infection with high-risk (HR) types of human papillomavirus (HPV). Screening is primarily recommended for all men who have sex with men (MSM) and transgender women with HIV starting at age 35, and all people with HIV starting at age 45. After inspection and digital anorectal examination, anal cytology is collected. An HR-HPV test may be performed. If clinical abnormalities are present or if cytology shows "ASC-US or worse", a referral for high-resolution anoscopy (HRA) is indicated. If lesions are found during HRA, a biopsy should be obtained. Anal intraepithelial neoplasia (AIN) grade-III or AIN-II p16-positive correspond to high-grade dysplasia and require treatment. The most strongly recommended therapeutic options are electrocautery, 85% trichloroacetic acid, and surgical excision. Finally, the guideline discusses how these screening recommendations can be applied to individuals without HIV.