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.

Cancer risk in people living with HIV and solid organ transplant recipients: a systematic review and meta-analysis.

BACKGROUND: Systematic evaluations of cancer risk in people living with HIV or AIDS (PLHIV) and solid organ transplant recipients provide unique insights into the role of the immune system in cancer development. In this systematic review and meta-analysis, we expand previous analyses of cancer risk for these two immunocompromised populations. METHODS: We considered studies published in English and listed on PubMed or Embase up to July 1, 2022. Studies were eligible for inclusion if they used population-based registries and compared cancer incidence in PLHIV or solid organ transplant recipients with the general population in the same geographical area. We extracted the number of observed site-specific cancers and expected cases and calculated meta-standardised incidence ratios for cancer within PLHIV and solid organ transplant recipients. In solid organ transplant recipients meta-standardised incidence ratios were compared by organ type. This project is registered on PROSPERO, CRD42022366679. FINDINGS: 46 studies in PLHIV and 67 in solid organ transplant recipients were included in the analysis. Meta-standardised incidence ratios for cancers associated with human papillomavirus were increased in both populations; the highest meta-standardised incidence ratio in PLHIV was anal cancer (37·28 [95% CI 23·65-58·75], I2=97·4%), and in solid organ transplant recipients was cutaneous squamous cell carcinoma (45·87 [31·70-66·38], I2=99·0%). Meta-standardised incidence ratios were significantly increased for most non-HPV viral-infection-related cancers in both populations; the highest standard incidence ratios were for Kaposi sarcoma (PLHIV: 801·52 [95% CI 200·25-3208·13], I2=100·0%; solid organ transplant recipients: 47·31 [23·09-96·95], I2=87·7%) and non-Hodgkin lymphoma (32·53 [19·64-53·87], I2=99·8%; 10·24 [8·48-12·35], I2=94·9%). Eight types of cancer with no known viral cause showed an increased risk in solid organ transplant recipients only; no cancer type showed increased risk in PLHIV only. INTERPRETATION: Cancer risk was increased for a range of infection-related cancers in both PLHIV and solid organ transplant recipients, but divergent results in these and other cancers have emerged. The cancer risk patterns probably reflect variances in the degree of impaired immunity, exposure to carcinogenic viruses, and perhaps exposure to carcinogenic immunosuppressive agents. FUNDING: US National Cancer Institute, National Institutes of Health.

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.

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.

Incidence and Clearance of Anal Human Papillomavirus Infection in 16 164 Individuals, According to Human Immunodeficiency Virus Status, Sex, and Male Sexuality: An International Pooled Analysis of 34 Longitudinal Studies.

BACKGROUND: Understanding 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. METHODS: We 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. RESULTS: Human 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. CONCLUSIONS: This 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.

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.

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.

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.

Vulvar High-Grade Squamous Intraepithelial Lesions and Cancer as a Risk Factor for Anal Cancer: A Review.

OBJECTIVES: Anal squamous cell carcinoma (ASCC) has a higher incidence described in certain groups, namely, in women with vulvar high-grade squamous intraepithelial lesions (vHSILs) and/or human papillomavirus squamous cell carcinoma (VSCC). This review describes terminology, vHSIL, and VSCC in their association with ASCC and the published recommendations for early detection of this cancer in these women. MATERIALS AND METHODS: A narrative review was conducted by the authors on vHSIL and VSCC as risk factors for ASCC. RESULTS: The ASCC and VSCC incidence are increasing. Women with vHSIL and/or VSCC can present with ASCC at diagnosis, being one of the highest-risk groups. Suspicious symptoms include rectal bleeding, pain, and a sensation of an anal mass. Digital anorectal examination can help detect early ASCC. Sensitivity of anal cytology in women with vHSIL and VSCC seems low, with the exception of immunosuppressed women with genital neoplasia (cervix, vagina, and vulva). There are still insufficient data on high-resolution anoscopy in women with vHSIL and/or VSCC as a screening method. CONCLUSIONS: Clinicians need be aware that women with vHSIL and VSCC comprise one of the highest-risk groups for ASCC. Inquiring suggestive symptoms of ASCC and a digital anorectal examination can help in the early detection of this type of cancer.

Intra-Anal Imiquimod Cream against Human Papillomavirus Infection in Men Who Have Sex with Men Living with HIV: A Single-Arm, Open-Label Pilot Study.

Men who have sex with men (MSM) living with HIV have a high prevalence and incidence of anal high-risk human papillomavirus (hrHPV) and anal cancer. We conducted an open-label, single-arm pilot study to examine the tolerability of imiquimod cream among MSM aged ≥18 years, living with HIV, who tested positive for anal hrHPV at Melbourne Sexual Health Centre between April 2018 and June 2020. We instructed men to apply 6.25 mg imiquimod intra-anally and peri-anally 3 doses per week for 16 weeks (period 1) and then one dose per week for a further 48 weeks (period 2). Twenty-seven MSM enrolled in period 1 and 24 (86%) applied at least 50% of doses. All men reported adverse events (AEs), including 39.5% grade 1, 39.5% grade 2, and 21% grade 3 AEs on at least one occasion. Eighteen MSM (67%) temporarily stopped using imiquimod during period 1, most commonly due to local AEs (n = 11) such as irritation and itching. Eighteen MSM continued in period 2 and all applied at least 50% of doses with no treatment-limiting AEs reported. Imiquimod 3 doses per week caused local AEs in most men and was not well tolerated. In contrast, once-a-week application was well tolerated over 48-weeks with no treatment-limiting AEs.

Epidemiology of anal human papillomavirus infection and high-grade squamous intraepithelial lesions in 29 900 men according to HIV status, sexuality, and age: a collaborative pooled analysis of 64 studies.

BACKGROUND: Robust age-specific estimates of anal human papillomavirus (HPV) and high-grade squamous intraepithelial lesions (HSIL) in men can inform anal cancer prevention efforts. We aimed to evaluate the age-specific prevalence of anal HPV, HSIL, and their combination, in men, stratified by HIV status and sexuality. METHODS: We did a systematic review for studies on anal HPV infection in men and a pooled analysis of individual-level data from eligible studies across four groups: HIV-positive men who have sex with men (MSM), HIV-negative MSM, HIV-positive men who have sex with women (MSW), and HIV-negative MSW. Studies were required to inform on type-specific HPV infection (at least HPV16), detected by use of a PCR-based test from anal swabs, HIV status, sexuality (MSM, including those who have sex with men only or also with women, or MSW), and age. Authors of eligible studies with a sample size of 200 participants or more were invited to share deidentified individual-level data on the above four variables. Authors of studies including 40 or more HIV-positive MSW or 40 or more men from Africa (irrespective of HIV status and sexuality) were also invited to share these data. Pooled estimates of anal high-risk HPV (HR-HPV, including HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68), and HSIL or worse (HSIL+), were compared by use of adjusted prevalence ratios (aPRs) from generalised linear models. FINDINGS: The systematic review identified 93 eligible studies, of which 64 contributed data on 29 900 men to the pooled analysis. Among HIV-negative MSW anal HPV16 prevalence was 1·8% (91 of 5190) and HR-HPV prevalence was 6·9% (345 of 5003); among HIV-positive MSW the prevalences were 8·7% (59 of 682) and 26·9% (179 of 666); among HIV-negative MSM they were 13·7% (1455 of 10 617) and 41·2% (3798 of 9215), and among HIV-positive MSM 28·5% (3819 of 13 411) and 74·3% (8765 of 11 803). In HIV-positive MSM, HPV16 prevalence was 5·6% (two of 36) among those age 15-18 years and 28·8% (141 of 490) among those age 23-24 years (ptrend=0·0091); prevalence was 31·7% (1057 of 3337) among those age 25-34 years and 22·8% (451 of 1979) among those age 55 and older (ptrend<0·0001). HPV16 prevalence in HIV-negative MSM was 6·7% (15 of 223) among those age 15-18 and 13·9% (166 of 1192) among those age 23-24 years (ptrend=0·0076); the prevalence plateaued thereafter (ptrend=0·72). Similar age-specific patterns were observed for HR-HPV. No significant differences for HPV16 or HR-HPV were found by age for either HIV-positive or HIV-negative MSW. HSIL+ detection ranged from 7·5% (12 of 160) to 54·5% (61 of 112) in HIV-positive MSM; after adjustment for heterogeneity, HIV was a significant predictor of HSIL+ (aPR 1·54, 95% CI 1·36-1·73), HPV16-positive HSIL+ (1·66, 1·36-2·03), and HSIL+ in HPV16-positive MSM (1·19, 1·04-1·37). Among HPV16-positive MSM, HSIL+ prevalence increased with age. INTERPRETATION: High anal HPV prevalence among young HIV-positive and HIV-negative MSM highlights the benefits of gender-neutral HPV vaccination before sexual activity over catch-up vaccination. HIV-positive MSM are a priority for anal cancer screening research and initiatives targeting HPV16-positive HSIL+. FUNDING: International Agency for Research on Cancer.

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.

Effect of age on the association between recreational drug use and sexual risk behaviour: a cross-sectional observational analysis.

Recreational drug use (RDU) among gay and bisexual men (GBM) is associated with higher-risk sexual behaviours, however this has not been well defined among older GBM. We investigated the association between RDU and sexual behaviours among older GBM in Sydney, Australia. 617 GBM aged 35-79 years self-reported their RDU in the past 6 months and sexual behaviours. Age-stratified univariable associations between RDU and behaviour were examined. GBM aged 35-44 years were the most likely to report RDU, with rates decreasing with increasing age (Ptrend < 0.001). Associations between RDU and higher-risk sexual behaviours were most consistently found among GBM aged 35-54 years.