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BackgroundUnderstanding the natural history of anal high-risk human papillomavirus (hrHPV) infection is key for designing anal cancer prevention programs but has not been systematically characterized.MethodsWe reanalyzed data from 34 studies including 16 164 individuals in 6 risk groups defined by human immunodeficiency virus (HIV) status, sex, and male sexuality: men who have sex with men (MSM) and people with HIV (MSMWH), HIV-negative MSM, women with HIV (WWH), HIV-negative women, men who have sex with women (MSW) with HIV (MSWWH), and HIV-negative MSW. We used Markov models to estimate incidence and clearance of 13 hrHPV types and their determinants.ResultsHuman papillomavirus (HPV) 16 had the highest incidence-clearance ratio of the hrHPV types. MSMWH had the highest hrHPV incidence (eg, 15.5% newly HPV-16 infected within 2 years), followed by HIV-negative MSM (7.5%), WWH (6.6%), HIV-negative women (2.9%), MSWWH (1.7%), and HIV-negative MSW (0.7%). Determinants of HPV-16 incidence included HIV status and number of sexual partners for MSM, women, and MSW, and anal sex behavior for MSM only. HPV-16 clearance was lower for people with HIV (PWH) and lower for prevalent than incident infection. Among MSM, increasing age was associated with lower clearance of prevalent, but not incident, HPV-16 infection.ConclusionsThis robust and unifying analysis of anal hrHPV natural history is essential to designing and predicting the impact of HPV vaccination and HPV-based screening programs on anal cancer prevention, particularly in MSM and PWH. Importantly, it demonstrates the higher carcinogenic potential of longstanding anal prevalent hrHPV infection than more recent incident infection.

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]

Background: Incidence of anal cancer is highest in gay and bisexual men (GBM). Better understanding of the natural history of anal high-risk human papillomavirus (hrHPV) infection is needed for anal cancer prevention.Methods: The Study of the Prevention of Anal Cancer was a 3-year study of Australian GBM, aged 35 years or older. We examined incidence, clearance, and risk factors for 13 hrHPV types at baseline and 3 annual visits.Results: In 525 men with ≥ 2 visits, 348 (66.3%) acquired ≥ 1 incident hrHPV infection. HPV16 incidence rates were similar, but non-16 hrHPV incidence was higher in HIV-positive (51.8/100 person years [PY]) than HIV-negative men (36.5/100 PY, P < .001). Annual clearance rates of HPV16 (13.21/100 PY, 95% confidence interval, 10.53-16.56) were lower than for other hrHPV types. hrHPV clearance rates were not associated with HIV overall but were significantly lower in those with a lower nadir CD4 (<200 cells/µL) for HPV16 (P = .015) and other hrHPV types (P = .007).Conclusions: Higher incidence of non-16 hrHPV types, coupled with lower clearance of non-16 hrHPV types in those with past impaired immune function, is consistent with the greater role of non-16 hrHPV in anal cancer in HIV-positive people.Australia New Zealand Clinical Trials Registry: ANZCTR365383. [ABSTRACT FROM AUTHOR]

Background Gay and bisexual men (GBM) are disproportionately affected by anal cancer. Prevention is hindered by incomplete understanding of the natural history of its precursor, anal high-grade squamous intraepithelial lesions (HSIL). Methods The Study of the Prevention of Anal Cancer, conducted between 2010 and 2018, enrolled human immunodeficiency virus (HIV)-positive and HIV-negative GBM aged ≥35 years. Anal cytology and high-resolution anoscopy (HRA) were performed at baseline and 3 annual visits. A composite HSIL diagnosis (cytology ± histology) was used. Cytological high-grade squamous intraepithelial lesions (cHSIL) incidence and clearance rates were calculated with 95% confidence intervals (CIs). Predictors were calculated using Cox regression with hazard ratios (HRs) and 95% CIs. Results Among 617 men, 220 (35.7%) were HIV-positive, median age 49 years. And 124 incident cHSIL cases occurred over 1097.3 person-years (PY) follow-up (11.3, 95% CI 9.5–13.5 per 100 PY). Significant bivariate predictors of higher incidence included age <45 years (HR 1.64, 95% CI 1.11–2.41), HIV positivity (HR 1.43, 95% CI.99–2.06), prior SIL diagnosis (P -trend <.001) and human papillomavirus (HPV)16 (HR 3.39, 2.38–4.84). Over 695.3 PY follow-up, 153 HSIL cleared (clearance 22.0, 95% CI 18.8–25.8 per 100 PY). Predictors were age < 45 years (HR 1.52, 1.08–2.16), anal intraepithelial neoplasia (AIN)2 rather than AIN3 (HR 1.79, 1.29–2.49), smaller lesions (HR 1.62, 1.11–2.36) and no persistent HPV16 (HR 1.72, 1.23–2.41). There was 1 progression to cancer (incidence 0.224, 95% CI.006–1.25 per 100 PY). Conclusion These data strongly suggest that not all anal HSIL detected in screening requires treatment. Men with persistent HPV16 were less likely to clear HSIL and are more likely to benefit from effective HSIL treatments. Clinical Trials Registration Australia New Zealand Clinical Trials Registry (ANZCTR365383). [ABSTRACT FROM AUTHOR]

Background Anal symptoms may indicate serious pathology. Receptive anal intercourse (RAI) and sexually transmissible infections (STIs) may contribute to a higher prevalence of symptoms among gay and bisexual men (GBM). This study investigated associations with anal symptoms among GBM.Methods: The Study of the Prevention of Anal Cancer was a longitudinal study of anal human papillomavirus and related lesions in Sydney, Australia. GBM aged ≥35 years were recruited from community settings between September 2010 and August 2015. Information about anal symptoms (discharge, itch, pain defecating, lump, bleeding, 'sores', tearing, tenesmus), STIs and sexual behaviours was collected. High-resolution anoscopy (HRA) and STI testing were performed. Logistic regression analyses on baseline data were performed to assess associations with each symptom.Results: Among 616 participants (median age 49 years, 35.9% HIV positive), 35.3% reported at least one anal symptom within the past week and 65.3% were diagnosed with fistula, fissure, ulcer, warts, haemorrhoids and/or perianal dermatoses at HRA. Anal symptoms were not associated with anal chlamydia, gonorrhoea, warts or syphilis. Self-reported 'sores' were associated with previous anal herpes simplex virus (HSV; P < 0.001). 'Sores' (P < 0.001), itch (P = 0.019), discharge (P = 0.032) and lump (P = 0.028) were independently associated with ulceration. Among participants diagnosed with fissure, fistulae, haemorrhoids and perianal dermatoses, 61.9%, 100%, 62.0% and 63.9% respectively were asymptomatic. Only self-reported anal tear was independently associated with recent RAI.Conclusions: Previous anal HSV was the only STI associated with any symptom. Anal pathology was highly prevalent, but often asymptomatic. Anal symptoms do not appear to be useful markers of most anal pathology in GBM. [ABSTRACT FROM AUTHOR]

Incidence and mortality rates of anal cancer are increasing globally. More than 90% of anal squamous cell carcinomas (ASCC) are associated with human papillomavirus (HPV). Studies on HPV-related anogenital lesions have shown that patterns of methylation of viral and cellular DNA targets could potentially be developed as disease biomarkers. Lesion-specific DNA isolated from formalin-fixed paraffin-embedded (FFPE) tissues from existing or prospective patient cohorts may constitute a valuable resource for methylation analysis. However, low concentrations of DNA make these samples technically challenging to analyse using existing methods. We therefore set out to develop a sensitive and reproducible nested PCR-pyrosequencing based method to accurately quantify methylation at 10 CpG sites within the E2BS1, E2BS2,3,4 and Sp1 binding sites in the viral upstream regulatory region of HPV16 genome. Methylation analyses using primary and nested PCR-pyrosequencing on 52 FFPE tissue [26 paired whole tissue sections (WTS) and laser capture microdissected (LCM) tissues] from patients with anal squamous intraepithelial lesions was performed. Using nested PCR, methylation results were obtained for the E2BS1, E2BS2,3,4 and Sp1 binding sites in 86.4% of the WTS and 81.8% of the LCM samples. Methylation patterns were strongly correlated within median values of matched pairs of WTS and LCM sections, but overall methylation was higher in LCM samples at different CpG sites. High grade lesions showed low methylation levels in the E2BS1 and E2BS2 regions, with increased methylation detected in the E2BS,3,4/Sp1 regions, showing the highest methylation at CpG site 37. The method developed is highly sensitive in samples with low amounts of DNA and demonstrated to be suitable for archival samples. Our data shows a possible role of specific methylation in the HPV16 URR for detection of HSIL. [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]