Does use of anal cytology as a triage test improve the performance of high-risk human papillomavirus screening in gay and bisexual men for anal cancer prevention?

Anal high-risk human papillomavirus (HRHPV) testing-based anal cancer screening gay and bisexual men (GBM) is associated with high sensitivity, but low specificity. We report the potential role of triage use of anal cytology with HRHPV testing in detecting 12-month persistent anal high-grade squamous epithelial lesions (HSIL) in a cohort of GBM in Sydney, Australia. Participants were GBM from the Study of the Prevention of Anal Cancer (SPANC) who underwent annual anal HPV testing, cytology, and high-resolution anoscopy (HRA)-guided histology. The sensitivity and specificity of five screening algorithms based on HRHPV test results with triage use of anal cytology (atypical squamous cells of undetermined significance (ASCUS) and atypical squamous cells, cannot exclude HSIL (ASC-H) used as referral thresholds) were compared to these of HRHPV testing and anal cytology alone. A total of 475 men who had valid HRHPV, cytological, and histological results at both baseline and first annual follow-up visits were included, median age 49 years (inter-quartile range: 43-56) and 173 (36.4%) GBM with human immunodeficiency virus. Of all triage algorithms assessed, two had comparable sensitivity with HRHPV testing alone in detecting persistent anal HSIL, but ~20% higher specificity and 20% lower HRA referral rates. These two algorithms involved the immediate referral of those with HPV16 and for those with non-16 HRHPV either immediate or delayed (for 12 months) referral, depending on cytology result at baseline. Triage use of anal cytology in GBM testing positive for anal HRHPV increases specificity and reduces referral rates while maintaining high sensitivity in detection of HSIL.

Self-collected versus clinician-collected anal swabs for anal cancer screening: A systematic review and meta-analysis.

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.

Factors Associated With Recent Decline in Anal Health Among Older Gay and Bisexual Men: A Cross-sectional Analysis.

ABSTRACT: We investigated factors associated with "worse than usual" anal health among gay and bisexual men aged ≥35 years recruited to a longitudinal study of anal human papillomavirus infection/lesions from September 2010 to August 2015.Among 616 participants (median age 49 years; 36% HIV-positive), 42 (6.8%) reported worse than usual anal health in the last 4 weeks. Associated factors included spending less time with gay friends (odds ratio [OR] = 2.25, 95% CI = 1.06-4.77), most time "feeling down"(OR = 9.17, 95% CI = 2.94-28.59), reduced libido (OR = 2.90, 95% CI = 1.52-5.52), current anal symptoms (OR = 6.55, 95% CI = 2.54-16.90), recent anal wart diagnosis (OR = 4.33, 95% CI = 1.98-9.49), and fear of developing anal cancer (OR = 9.34, 95% CI = 4.52-19.28).Concerns regarding anal health should be routinely discussed by clinicians, and potentially associated psychosocial, physical, and sexual issues further explored.

International Anal Neoplasia Society's consensus guidelines for anal cancer screening.

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.

Anal cancer: a 20-year retrospective study from Australia.

BACKGROUNDS: Anal cancer is an uncommon condition, occurring at higher rates in specific subpopulations. Clinical experience is limited and substantial changes have recently occurred in our understanding of this condition. We, therefore, set out to characterize patients presenting with anal cancer and investigate whether there have been any changes over the past 20 years. METHODS: Retrospective audit of cases identified from pathology and clinical databases during the period 1 January 2000 to 31 December 2019. RESULTS: Two hundred and sixteen patients had anal squamous cell carcinomas, comprising 160 (74%) males and 56 (26%) females. Mean age at initial diagnosis was 55.1 ± 11.20 for males and 60.6 ± 15.18 for females (P = 0.02). At initial diagnosis, HIV-positive cases were significantly younger than HIV negative cases (mean 52.2 ± 9.35 vs. 62.8 ± 11.61, P < 0.001); 46% of cases were classified as intra-anal, 29% perianal and 25% both; 52% were > 2 cm at diagnosis. At presentation, intra-anal cases were larger and more advanced than perianal cases (P = 0.049). Compared with the period 2000-2009, anal cancers presented more commonly in 2010-2019 (148 vs. 76), were more likely to occur in HIV-negative people and to be diagnosed at a similar stage. CONCLUSION: The number of anal cancer cases almost doubled over the study period and people living with HIV presented 10 years younger than others. Perianal cases presented earlier than those originating in intra-anal locations. Together with the large size at diagnosis, this suggests the potential value of screening, particularly for intra-anal cancers in those at high risk.

Cost-effectiveness of screening and treating anal pre-cancerous lesions among gay, bisexual and other men who have sex with men living with HIV.

Background: Gay, bisexual and other men who have sex with men (GBM) living with HIV have a substantially elevated risk of anal cancer (85 cases per 100,000 person-years vs 1-2 cases per 100,000 person-years in the general population). The precursor to anal cancer is high-grade squamous intraepithelial lesion (HSIL). Findings regarding the cost-effectiveness of HSIL screening and treatment in GBM are conflicting. Using recent data on HSIL natural history and treatment effectiveness, we aimed to improve upon earlier models. Methods: We developed a Markov cohort model populated using observational study data and published literature. Our study population was GBM living with HIV aged ≥35 years. We used a lifetime horizon and framed our model on the Australian healthcare perspective. The intervention was anal HSIL screening and treatment. Our primary outcome was the incremental cost-effectiveness ratio (ICER) as cost per quality-adjusted life-year (QALY) gained. Findings: Anal cancer incidence was estimated to decline by 44-70% following implementation of annual HSIL screening and treatment. However, for the most cost-effective screening method assessed, the ICER relative to current practice, Australian Dollar (AUD) 135,800 per QALY gained, remained higher than Australia's commonly accepted willingness-to-pay threshold of AUD 50,000 per QALY gained. In probabilistic sensitivity analyses, HSIL screening and treatment had a 20% probability of being cost-effective. When the sensitivity and specificity of HSIL screening were enhanced beyond the limits of current technology, without an increase in the cost of screening, ICERs improved but were still not cost-effective. Cost-effectiveness was achieved with a screening test that had 95% sensitivity, 95% specificity, and cost ≤ AUD 24 per test. Interpretation: Establishing highly sensitive and highly specific HSIL screening methods that cost less than currently available techniques remains a research priority. Funding: No specific funding was received for this analysis.

Performance of Human Papillomavirus Attribution Algorithms to Predict Causative Genotypes in Anal High-Grade Lesions.

BACKGROUND: Gay and bisexual men (GBM) are at increased risk of human papillomavirus (HPV)-associated anal high-grade squamous intraepithelial lesions (HSILs). Understanding the fractions of HSILs attributable to HPV genotypes is important to inform potential impacts of screening and vaccination strategies. However, multiple infections are common, making attribution of causative types difficult. Algorithms developed for predicting HSIL-causative genotype fractions have never been compared with a reference standard in GBM. METHOD: Samples were from the Study of the Prevention of Anal Cancer. Baseline HPV genotypes detected in anal swab samples (160 participants) were compared with HPV genotypes in anal HSILs (222 lesions) determined by laser capture microdissection (LCM). Five algorithms were compared: proportional, hierarchical, maximum, minimum, and maximum likelihood estimation. RESULTS: All algorithms predicted HPV-16 as the most common HSIL-causative genotype, and proportions differed from LCM detection (37.8%) by algorithm (with differences of -6.1%, +20.9%, -20.4%, +2.9%, and +2.2% respectively). Fractions predicted using the proportional method showed a strong positive correlation with LCM, overall (R = 0.73 and P = .002), and by human immunodeficiency virus (HIV) status (HIV positive, R = 0.74 and P = .001; HIV-negative, R = 0.68 and P = .005). CONCLUSIONS: Algorithms produced a range of inaccurate estimates of HSIL attribution, with the proportional algorithm performing best. The high occurrence of multiple HPV infections means that these algorithms may be of limited use in GBM.

Comparison of four assays for human papillomavirus detection in the anal canal.

OBJECTIVE: Anal cancer is preceded by high-risk human papillomavirus (HRHPV) infection, predominantly HPV16. No HPV assay is licenced for use in anal screening. We aimed to determine the sensitivity and specificity of four anal canal swab HPV assays to predict high-grade squamous epithelial lesions (HSIL). METHODS: In a cohort of Australian HIV-positive and negative gay and bisexual men, we compared the sensitivity and specificity of detection of 13 anal HRHPV genotypes by Linear Array (LA), Cobas 4800, EuroArray, and Anyplex II HPV28 (+ and ++ cut offs), compared their ability to predict prevalent anal HSIL, and compared anal canal HRHPV detection with HRHPV isolated from HSIL using laser capture microdissection (LCM). RESULTS: A total of 475 participants had baseline results available for all four assays (166, 35.0% HIV positive), and 169 participants had a diagnosis of cytological and/or histological HSIL. The HPV16 and any HRHPV detection were highest with Anyplex II HPV28 (+) (156, 32.8% 95% CI 28.6-37.2 and 359, 75.6%, 95% CI 71.5-79.4, respectively). For detection of concurrent HSIL and HPV16, the assay sensitivity was similar, ranging from 49.1%, 95% CI 41.4-56.9 (Anyplex II HPV28 ++) to 55.0%, 95% CI 47.2-62.7 (Anyplex II HPV28 +). For concurrent HSIL and any HRHPV detection, EuroArray was more specific than Anyplex II HPV28 (+) (45.9% 95% CI 40.2-51.7 vs 36.7%, 95% CI 31.3-42.4, p = 0.021) and had comparable specificity with Anyplex II HPV28 (++) (45.9% vs 47.2%, 95% CI 41.5-53.0, p = 0.75). All assays had high sensitivities for predicting HPV16 detected on LCM (92.5-97.5%). Anyplex II HPV28 and EuroArray were significantly more sensitive than LA for lesions caused by non-HPV16 HRHPV types on LCM. DISCUSSION: Anyplex II HPV28 and EuroArray detected more non-16 HRHPV genotypes than LA. Increasing the Anyplex II HPV28 cutoff improved specificity without compromising sensitivity for detection of concurrent HSIL.

Anal Cancer Screening and Prevention: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Guidelines.

In June 2019 the Centers for Disease Control and Prevention (CDC) convened an advisory group to assist in development of the 2021 CDC sexually transmitted infections (STI) guidelines. The advisory group on anal cancer screening and prevention met to formulate key questions in this field. The group examined published literature and abstracts to assess evidence and give recommendations for development of the CDC guidelines. This article summarizes key questions, evidence, recommendations, and areas for further research for the screening, diagnosis, and prevention of anal cancer.

Gene methylation of CADM1 and MAL identified as a biomarker of high grade anal intraepithelial neoplasia.

Human papillomavirus (HPV) is detected in up to 96% of anal squamous cell cancers, where screening programs needed. However, the best methodology is still undetermined. Host DNA methylation markers CADM1, MAL and miR124 have been identified in cervical disease, but not anal disease. Anal swabs varying by disease grade were assessed for DNA methylation of CADM1, MAL and miR124-2. Each marker was compared across disease grades, stratified by HPV and HIV status. Receiver operating characteristic curves identified the predictive value of significant gene candidates. CADM1 methylation was significantly higher in high-grade squamous intraepithelial lesions (HSIL) compared with low-grade (LSIL) (p = 0.005) or normal (p < 0.001) samples with 67.2% correctly identified as HSIL. MAL methylation was significantly (p = 0.002) increased in HSIL compared with LSIL in HIV positive participants with 79.8% correctly indicated as HSIL. Gene miR124-2, showed no difference between disease grades. Biomarkers with established diagnostic value in cervical disease have limited utility in the prediction of anal disease, with CADM1 identified as a marker with screening potential in a gay and bisexual men (GBM) population and MAL in HIV positive GBM population. New markers specific to the anal mucosa are required to improve triage of high-risk individuals.

Possible Reactivation of Latent Anal Human Papillomavirus Associated with Markers of Immune Dysfunction in Gay and Bisexual Men.

BACKGROUND: It is unknown whether reactivation of human papillomavirus (HPV) after latency occurs in the anus. We measured incidence and predictors of incident anal HPV in sexually inactive gay and bisexual men (GBM) as a surrogate of HPV reactivation. METHODS: The Study of the Prevention of Anal Cancer collected data on sexual behavior, anal cytology, HPV DNA, histology and HPV serology. HPV incidence during periods when zero sexual partners were reported in the last six months at both the current and previous annual visit ("no sexual activity") was analyzed by Cox regression using the Wei-Lin-Weissfeld method to determine univariable predictors. RESULTS: Of 617 men enrolled, 525 had results for ≥2 visits, of whom 58 (11%) had ≥ one period of "no sexual activity". During sexually inactive periods, there were 29 incident high risk HPV infections in 20 men, which occurred more commonly in older men (Ptrend = 0.010), HIV-positive men (HR = 3.12; 95% CI, 0.91-16.65), longer duration of HIV (Ptrend = 0.028), history of AIDS defining illness (P = 0.010), lower current (P = 0.010) and nadir CD4 count (P = 0.014). For 18 of 29 infections with available results, 12 men remained type-specific HRHPV L1 seronegative. None were consistently seropositive. A new diagnosis of HSIL occurred in only two men, caused by an HPV type other than the incident type. CONCLUSIONS: Our findings suggest that in sexually inactive GBM, anal HRHPV incidence is relatively common, and is associated with increasing age and immune dysfunction, a pattern consistent with HPV reactivation. IMPACT: Reactivation of anal HPV may occur.

Sexual behaviours associated with incident high-risk anal human papillomavirus among gay and bisexual men.

OBJECTIVE: High-risk human papillomavirus (HRHPV) causes anal cancer, which disproportionately affects gay and bisexual men (GBM). We examined sexual behaviours associated with incident anal HRHPV in an observational cohort study of GBM in Sydney, Australia. METHODS: GBM aged 35 years and above were enrolled in the Study of the Prevention of Anal Cancer. Detailed information on sexual practices in the last 6 months, including receptive anal intercourse (RAI) and non-intercourse receptive anal practices, was collected. Anal human papillomavirus (HPV) testing was performed at the baseline and three annual follow-up visits. Risk factors for incident HRHPV were determined by Cox regression using the Wei-Lin-Weissfeld method. RESULTS: Between 2010 and 2015, 617 men were recruited and 525 who had valid HPV results at baseline and at least one follow-up visit were included in the analysis. The median age was 49 years (IQR 43-56) and 188 (35.8%) were HIV-positive. On univariable analysis, incident anal HRHPV was associated with being HIV-positive (p<0.001), having a higher number of recent RAI partners regardless of condom use (p<0.001 for both), preference for the receptive position during anal intercourse (p=0.014) and other non-intercourse receptive anal sexual practices, including rimming, fingering and receptive use of sex toys (p<0.05 for all). In multivariable analyses, being HIV-positive (HR 1.46, 95% CI 1.09 to 1.85, p=0.009) and reporting condom-protected RAI with a higher number of sexual partners (p<0.001) remained significantly associated with incident HRHPV. When stratified by recent RAI, non-intercourse receptive anal practices were not associated with incident HRHPV in men who reported no recent RAI. CONCLUSION: GBM living with HIV and those who reported RAI were at increased of incident anal HRHPV. Given the substantial risk of anal cancer and the difficulty in mitigating the risk of acquiring anal HRHPV, HPV vaccination should be considered among sexually active older GBM. TRIAL REGISTRATION NUMBER: ANZCTR365383.

Prevalence of anal cytological abnormalities and high-risk human papillomavirus prevalence in kidney transplant recipients: A cross-sectional study.

BACKGROUND: Transplant recipients are at high-risk of anal squamous cell cancer. We aimed to estimate the prevalence of high-risk human papillomavirus (HPV) and high-grade squamous intraepithelial lesion (HSIL) and assess characteristics associated with results METHODS: We recruited kidney transplant recipients in a single-center, 2015-2018. Participants completed a clinical questionnaire and received an anal-swab sent for HPV-DNA and cytological testing RESULTS: A total of 97 (74%) of 125 recipients approached consented to participate. Participants were median 47 (IQR 40-55) years, 60% male and median 4.5 (IQR .9-13) months-since-transplant. Of 86 assessable samples, at least one HPV genotype was detected in 15 (17%) participants; 1 (1%) HPV16, 8 (9%) other high-risk HPV. Of 76 assessable cytology samples, 9 (12%) showed evidence of abnormality; 1 (1%) HSIL, 1 (1%) atypical-squamous-cells, cannot exclude HSIL. Both HSIL recipients had high-risk HPV and biopsy confirmed HSIL. High-risk HPV was detected in six (9%) recipients with normal cytology. History of sexually transmitted infection, and abnormal cervical pap smear in women, was associated with high-risk HPV and HSIL CONCLUSIONS: High-risk HPV and HSIL testing may identify kidney transplant recipients at higher risk of anal cancer. Longitudinal studies are needed to describe the natural history of anal cancer in transplant recipients.

Self-reported anal symptoms and their association with anal pathology among gay and bisexual men: a cross-sectional observational analysis.

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.

The Natural History of Anal High-grade Squamous Intraepithelial Lesions in Gay and Bisexual Men.

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).

HIV, Immune Dysfunction, and the Natural History of Anal High-Risk Human Papillomavirus Infection in Gay and Bisexual Men.

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.

Prevalence and Association of Perianal and Intra-Anal Warts with Composite High-Grade Squamous Intraepithelial Lesions Among Gay and Bisexual Men: Baseline Data from the Study of the Prevention of Anal Cancer.

Human papillomavirus (HPV) causes anal warts and anal squamous cell carcinoma (SCC). A higher incidence of anal cancer has been found among individuals previously diagnosed with anogenital warts. We aimed to investigate the association between anal warts and the presumed anal SCC precursor high-grade squamous intraepithelial lesion (HSIL), among participants in the Study of the Prevention of Anal Cancer (SPANC). SPANC was a longitudinal study of anal HPV infections and related lesions among gay and bisexual men (GBM) age 35 years and older, in Sydney, Australia. Anal cytology and high-resolution anoscopy were performed. Logistic regression was used to investigate the association between clinically diagnosed anal warts and intra-anal composite-HSIL (cytology and/or histology) at the baseline visit. The prevalence of HSIL within biopsies from intra-anal warts was calculated. Laser capture microdissection (LCM) and HPV-genotyping was performed on HSIL lesions. Among 616 participants at study entry, 165 (26.8%) and 51 (8.3%) had intra-anal and perianal warts, respectively. Warts were associated with composite-HSIL, even after adjustment for HIV status, age, lifetime receptive anal intercourse partner number, and smoking (perianal: aOR 2.13, 95% CI 1.17-3.87, p = 0.013; intra-anal: aOR 1.69, 95% CI 1.16-2.46, p = 0.006). HSIL was detected in 24 (14.5%) of 165 biopsies from intra-anal warts. Of 17 HSIL lesions, 16 (94.1%) had high-risk HPV detected by LCM. Anal warts were common. Prevalent anal warts were associated with composite-HSIL. HSIL may be detected within biopsies of intra-anal warts. Anal warts may be a useful addition to risk stratification for HSIL among GBM.