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Anal squamous cell carcinoma (ASCC) incidence is increasing globally. International consensus guidelines published in 2024 include HPV and/or cytology testing of anal swabs in those at greatest risk of ASCC. Self‐collected anal swabs may be important for increasing screening uptake, but evidence is needed as to their equivalence to clinician‐collected swabs. We searched Medline, Embase, Cochrane Library, and CINAHL databases for publications to 13 June 2023. Studies were included if reporting data on HPV testing, cytology testing, or acceptability, for both self‐ and clinician‐collected anal swabs. Risk of bias was assessed using the QUADAS‐2 assessment tool. The primary outcome was HPV and cytology sampling adequacy. Secondary outcomes were HPV and cytology results, and acceptability of collection methods. Thirteen papers describing 10 studies were eligible. Sample adequacy was comparable between self‐ and clinician‐collected swabs for HPV testing (meta‐adequacy ratio: 1.01 [95% CI 0.97–1.05]) but slightly lower for cytology by self‐collection (meta‐adequacy ratio: 0.91 [95% CI 0.88–0.95]). There was no significant difference in prevalence (meta‐prevalence ratio: 0.83 (95% CI 0.65–1.07) for any HR‐HPV, 0.98 (95% CI 0.84–1.14) for any HPV, and 0.68 (95% CI 0.33–1.37) for HPV16), or any cytological abnormality (meta‐prevalence ratio 1.01 [95% CI 0.86–1.18]). Only three papers reported acceptability results. Findings indicate self‐collection gives equivalent sample adequacy for HPV testing and ~ 10% inferior adequacy for cytological testing. Meta‐prevalence was similar for HPV and cytology, but confidence intervals were wide. Larger studies are required to definitively assess use of self‐collected swabs in anal cancer screening programs, including acceptability. [ABSTRACT FROM AUTHOR]

The International Anal Neoplasia Society (IANS) developed consensus guidelines to inform anal cancer screening use among various high‐risk groups. Anal cancer incidence estimates by age among risk groups provided the basis to identify risk thresholds to recommend screening. Guided by risk thresholds, screening initiation at age 35 years was recommended for men who have sex with men (MSM) and transgender women (TW) with HIV. For other people with HIV and MSM and TW not with HIV, screening initiation at age 45 years was recommended. For solid organ transplant recipients, screening initiation beginning from 10 years post‐transplant was recommended. For persons with a history of vulvar precancer or cancer, screening initiation was recommended starting within 1 year of diagnosis of vulvar precancer or cancer. Persons aged ≥45 years with a history of cervical/vaginal HSIL or cancer, perianal warts, persistent (>1 year) cervical HPV16, or autoimmune conditions could be considered for screening with shared decision‐making, provided there is adequate capacity to perform diagnostic procedures (high‐resolution anoscopy [HRA]). Anal cytology, high‐risk (hr) human papillomavirus (HPV) testing (including genotyping for HPV16), and hrHPV‐cytology co‐testing are different strategies currently used for anal cancer screening that show acceptable performance. Thresholds for referral for HRA or follow‐up screening tests are delineated. These recommendations from IANS provide the basis to inform management of abnormal screening results, considering currently available screening tools. These guidelines provide a pivotal foundation to help generate consensus among providers and inform the introduction and implementation of risk‐targeted screening for anal cancer prevention. [ABSTRACT FROM AUTHOR]

BACKGROUND In a cytology-based screening program intended to prevent anal cancer, the anal transformation zone (TZ) should be adequately sampled because it is the site most susceptible to the development of the cancer precursor, high-grade squamous intraepithelial lesion (HSIL). An adequate TZ component is defined as comprising at least 10 rectal columnar or squamous metaplastic cells. In the current study, the authors examined whether the presence of a TZ component in anal cytology correlated with the detection of histological HSIL. METHODS In a natural history study of anal human papillomavirus infection in homosexual men, all participants underwent liquid-based cytology and high-resolution anoscopy (HRA) with or without biopsy at each visit. True-negative cytology (negative cytology with non-HSIL biopsy or negative HRA), false-negative cytology (negative cytology with HSIL biopsy), and true-positive cytology (abnormal cytology with HSIL biopsy) were compared with regard to the presence or absence of a TZ component. RESULTS Of 617 participants, baseline results included 155 true-positive results, 191 true-negative results, and 31 false-negative results. The absence of an adequate TZ component was found to be significantly higher for false-negative (32.3%) than for either true-positive (11.0%; P = .0034) or true-negative (13.1%; P = .0089) results. CONCLUSIONS Significantly more false-negative cases lacked a TZ component compared with either true-positive or true-negative cases. TZ cells may be an important indicator of sample quality for anal cytology because, unlike cervical sampling, the anal canal is not visualized during cytology sampling. Cancer Cytopathol 2016;124:596-601. © 2016 American Cancer Society. [ABSTRACT FROM AUTHOR]

BACKGROUND Studies regarding the performance of anal cytology in which both the screening test (cytology) and the diagnostic test (high-resolution anoscopy [HRA]) are performed in all members of a screening population are rare. The authors evaluated the performance of liquid-based anal cytology in a cohort of homosexual men in Sydney, New South Wales, Australia. METHODS The Study of the Prevention of Anal Cancer (SPANC) is a 3-year prospective study of the natural history of anal human papillomavirus infection in homosexual men aged ≥35 years. At baseline, all participants underwent a liquid-based anal cytology test and HRA at the same clinical visit. Biopsies were obtained for histological assessment if lesions suspicious for human papillomavirus infection were visible during HRA. Using any cytological abnormality as the threshold, the sensitivity, specificity, and positive and negative predictive values were calculated against histologically diagnosed high-grade squamous intraepithelial lesions (HSILs). RESULTS Among 617 men recruited, the median age was 49 years (range, 35-79 years) and 35.7% were positive for the human immunodeficiency virus. Overall, the sensitivity of cytology was 83.2%, the specificity was 52.6%, the positive predictive value was 45.8%, and the negative predictive value was 86.7%. Specificity improved with increasing age ( P for trend =.041). Sensitivity was significantly higher in men with >1 anal octant of biopsy-confirmed HSIL (92.9% vs 77.7%; P = .010), and in those who had ≥10 metaplastic cells present on their cytology slides (87.5% vs 70.2%; P = .007). CONCLUSIONS Anal cytology was found to have a higher specificity in older men while maintaining sensitivity. Sensitivity was higher among those with more extensive HSILs and men with metaplastic cells present on cytology. Cancer Cytopathol 2016;124:415-24. © 2016 American Cancer Society. [ABSTRACT FROM AUTHOR]