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

Abstract

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.

Keywords: HIV; anal carcinoma; anal dysplasia.

FIGURE 1

Continuum of anal dysplasia. Schematic of the progression of anal dysplasia. Starting on the left, normal epithelium is displayed. Further right, HPV‐induced changes, including koilocytes,‐ occur increasingly and atypical keratinocytes can be found in the upper layers of the epithelium.

FIGURE 2

Preparation with 5% acetic acid. Before starting high‐resolution anoscopy, a cotton swab with 5% acetic acid should be applied for 1–2 minutes to better contrast for the consecutive examination. The combination of a cotton swab and a fleece compress usually works well. The swab can easily be inserted as follows: The anoscope is inserted, the guiding plug is removed, the swab is inserted into the anoscope, and the anoscope is removed with the swab remaining in the anal canal.

FIGURE 3

Diagram of the anal canal. The schematic of the anal canal displays the intraanal area affected by anal dysplasia. The transformation zone defines the beginning of the epithelium and appears as acetowhite after applying acetic acid. Anal papillae in the distal anal canal define the dentate line and, therefore, the end of the transformation zone.

FIGURE 4

Algorithm for anal carcinoma screening. The target populations are listed on the left side, with the highlighted groups designated as priority, while the screening process is outlined on the right side. Option #3 differs from Option #1 and Option #2 and is designed to enable all current healthcare providers to begin anal carcinoma screening immediately (further details can be found in the text of this guideline). ^§If high‐resolution anoscopy is unavailable, a conventional anoscopy without optical magnification may be offered. The potentially lower sensitivity of this method for detecting anal dysplasia, despite the same examination burden, should be discussed with patients. Abbr.: ASC‐H, atypical squamous cells, cannot exclude HSIL; ASC‐US, atypical squamous cells of undetermined significance; AIN, anal intraepithelial neoplasia; CA, carcinoma; CIN, cervical intraepithelial neoplasia; DARE, digital anorectal examination; HGAIN, high‐grade AIN; HPV, human papillomavirus; HRA, high‐resolution anoscopy; HR‐HPV, high‐risk HPV; HSIL, high‐grade squamous intraepithelial lesion; LSIL, low‐grade squamous intraepithelial lesion; MSM, men who have sex with men; NILM, negative for intraepithelial lesion or malignancy; PIN, penile intraepithelial neoplasia; SOTR, solid organ transplant recipients; TGW, transgender women; VIN, vulvar intraepithelial neoplasia

FIGURE 5

Cofactors influencing the incidence of anal dysplasia. Green indicates a lower, while red indicates a higher risk for anal dysplasia. Each row represents a specific factor, with its trend towards a decrease (negative) or an increase (positive) visually represented by the corresponding color. Examples: (1) increasing age is associated with a higher risk of anal dysplasia, and (2) the absence of HPV vaccination before age 26 is associated with a greater occurrence of anal dysplasia. Abbr.: AIN, anal intraepithelial neoplasia; CIN, cervical intraepithelial neoplasia; HPV, human papillomavirus; MSM, men who have sex with men; PIN, penile intraepithelial neoplasia; TGW, transgender women; VIN, vulvar intraepithelial neoplasia.