Strategies for screening and early detection of anal cancers: A narrative and systematic review and meta-analysis of cytology, HPV testing, and other biomarkers

Emerging advances and future opportunities in the molecular and therapeutic landscape of anal cancer

Anal squamous cell carcinoma (ASCC) is a rare malignancy with an increasing incidence. Primary chemoradiotherapy (CRT) is the standard-of-care treatment for patients with localized ASCC. In the metastatic setting, trials testing immune-checkpoint inhibitor monotherapy have demonstrated outcomes similar to those of patients receiving chemotherapy. Conversely, adding the anti-PD-1 antibody retifanlimab to chemotherapy in patients with recurrent or metastatic ASCC has been shown to significantly improve outcomes. Despite considerable efforts to develop personalized therapy, treatment guidance and prognosis remain reliant on baseline clinical characteristics. An improved understanding of the molecular characteristics of ASCC has provided insights into the mechanisms that mediate tumour progression and response to CRT. For example, human papillomavirus (HPV) infection is known to have an aetiological role in most ASCCs and can modulate cellular responses to CRT via several distinct mechanisms. In this Review, we summarize emerging advances in the molecular and therapeutic landscape of ASCC, including the implementation of biomarkers for treatment guidance and translation into new therapeutic approaches, with HPV infection constituting a global determinant of both tumour biology and clinical outcome. We also discuss the rationale for combining immune-checkpoint inhibitors with CRT in patients with HPV+ tumours.

Digital Cytology Combined With Artificial Intelligence Compared to Conventional Microscopy for Anal Cytology: A Preliminary Study

INTRODUCTION

Recent studies have shown that digital cytology (DC) coupled with artificial intelligence (AI) algorithms is a valid approach to the diagnosis of cervico-vaginal lesions using liquid-based cytology (LBC). We evaluated the use of these methods for anal LBC specimens.

METHODS

A series of 124 anal LBC slides previously diagnosed by conventional microscopy (CC) were reviewed with a DC/AI system that generated a gallery of images. Diagnoses based on the selected images, according to the 2014 Bethesda System for Reporting Cervical Cytology, were compared to CC.

RESULTS

Overall, CC and DC/AI approaches detected a similar number of abnormal (ASC-US+) cases (63 and 62 cases, respectively). We observed an exact concordance between CC and DC in 70 (57.9%) cases, corresponding to a moderate agreement between the two approaches (κ = 0.41, p < 0.001). A moderate agreement (κ = 0.48, p < 0.001) was also found when positive cases were stratified into 'low-grade' (ASC-US, LSIL) and 'high-grade' lesions (ASC-H, HSIL). The DC/AI system detected more cases of higher severity (ASC-H, HSIL: 9 and 2 cases, respectively) than CC (3 cases classified as HSIL).

CONCLUSIONS

The number of ASC-US+ cases detected by both systems was similar. The DC/AI system detected more cases of higher severity compared to the CC.

Human papilloma virus (HPV) mediated cancers: an insightful update

Human papillomavirus (HPV), a DNA virus, is a well-documented causative agent of several cancers, including cervical, vulvar, vaginal, penile, anal, and head & neck cancers. Major factors contributing to HPV-related cancers include persistent infection and the oncogenic potential of particular HPV genotypes. High-risk HPV strains, particularly HPV-16 and HPV-18, are responsible for over 70% of cervical cancer cases worldwide, as well as a significant proportion of other genital and head and neck cancers. At the molecular level, the oncogenic activity of these viruses is driven by the overexpression of E6 and E7 oncoproteins. These oncoproteins dysregulate the cell cycle, inhibit apoptosis, and promote the accumulation of DNA damage, ultimately transforming normal cells into cancerous ones. This review aims to provide a comprehensive overview of the recent advances in HPV-related cancer biology and epidemiology. The review highlights the molecular pathways of HPV-driven carcinogenesis, focusing on the role of viral oncoproteins in altering host cell targets and disrupting cellular signalling pathways. The review explores the therapeutic potential of these viral proteins, and discusses current diagnostic and treatment strategies for HPV-associated cancers. Furthermore, the review highlights the critical role of HPV in the development of various malignancies, emphasizing the persistent challenges in combating these cancers despite advancements in vaccination and therapeutic strategies. We also emphasize recent breakthroughs in utilizing biomarkers to monitor cancer therapy responses, such as mRNAs, miRNAs, lncRNAs, proteins, and genetic markers. We hope this review will serve as a valuable resource for researchers working on HPV, providing insights that can guide future investigations into this complex virus, which continues to be a major contributor to global morbidity and mortality.

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.

Anal Cancer Screening: 10-Year Experience of a Specialized Outpatient Clinic

In 2012, the Department of Visceral Surgery of the Lausanne University Hospital CHUV implemented a dedicated high-resolution anoscopy (HRA) outpatient clinic for surveillance and follow-up purposes. This 10-year longitudinal study analyzed 537 patients (2214 visits) using a structured screening protocol. Dysplastic lesions were detected in 49% of patients, predominantly low-grade squamous intraepithelial lesions (LSILs, 74%). Among LSIL cases, 6% progressed to high-grade squamous intraepithelial lesions (HSILs) within 24 months, reaching 25% cumulative progression at 36 months. Of HSIL patients, 3% developed carcinoma in situ after 48 months. Notably, no invasive carcinoma was observed during the follow-up. Four patients diagnosed with squamous cell carcinoma at initial screening were treated with chemoradiotherapy, and one required salvage surgery. Independent risk factors for the presence of higher-stage precancerous lesions (≥HSILs) were the presence of high-risk HPV genotypes (OR 14.5, 95% CI 5-42.2, p < 0.001), detectable HIV viral load (OR 5.4, 95% CI 1.8-16.7, p = 0.003), and symptoms at the first screening visit (OR 3.2, 95% CI 1.1-9.9, p = 0.04). HIV-positive status was associated with a trend towards an increased risk of progression (OR 2.79, p = 0.073). These findings highlight the importance of systematic follow-up and early intervention in high-risk populations to prevent anal cancer progression.

Early detection of carcinoma: correlating quantifiable tumor biomarkers with High-Resolution Microscopy (HRME) findings

INTRODUCTION

Cancer ranks as the second most prevalent cause of death worldwide, responsible for approximately 9.6 million deaths annually. Approximately one out of every six deaths is caused by cancer. About 80% of cancer deals with epithelial tissues located on the outer lines of the body cavity.

AREAS COVERED

This review study selected and analyzed recent works in the field of High Resolution Microendoscopy (HRME) that have been used to diagnose cancer in various organs such as cervical, esophageal, head & neck, and gastrointestinal.

EXPERT OPINION

The HRME modality will play a vital role in improving the diagnostic accuracy of carcinoma. HRME has shown promising statistical outcomes for diagnosing carcinoma, enabling the clinician to gain additional information before performing conventional tissue biopsy. A multimodal probe consisting of a macroscopic investigation aided by HRME modality for microscopic investigation can significantly reduce the number of unnecessary biopsies leading to overall improvement in patient wellness. The new directions of the HRME research would be in the light source and detection configuration, increasing the number of optical fiber cores, which improves the resolution of the image, AI-assisted automatic quantification of the key HRME parameters, and clinical studies with newer near-infrared regime-based contrast agents.

Mapping the HPV Landscape in South African Women: A Systematic Review and Meta-Analysis of Viral Genotypes, Microbiota, and Immune Signals

This systematic review and meta-analysis evaluate human papillomavirus (HPV) prevalence, genotype distribution, and associations with cervicovaginal microbiota and cytokine profiles among South African women, where cervical cancer ranks as the second most common cancer. PubMed, SCOPUS, and Web of Science were searched for studies on HPV infection up to 21 September 2024. The pooled prevalence was estimated using a random-effects model, with subgroup analyses by province, sample type, and HIV status. Publication bias was evaluated using funnel plots and Egger's test. Of the 19,765 studies screened, 120 met the inclusion criteria, comprising 83,266 participants. Results indicate a high HPV burden, with a pooled prevalence of 58% (95% CI: 52-64%), varying regionally from 53% (95% CI: 41-65%) to 64% (95% CI: 55-73%), with some regions under-researched. Cervical samples had the highest HPV prevalence (60% (95% CI: 54-66%)), while non-genital samples were less studied. High-risk (HR) HPV types, notably HPV 16 (7.5%), HPV 35 (4.1%), and HPV 18 (3.9%), were prominent, with HPV 35 emphasizing the need for expanded vaccine coverage. HIV-positive women had a higher pooled HPV prevalence (63% (95% CI: 55-71%)). Funnel plot analysis and Egger's test suggested a potential publication bias (p = 0.047). HPV-positive women exhibited lower Lactobacillus levels and an increase in Bacterial Vaginosis (BV)-associated species like Gardnerella, potentially supporting HPV persistence. Cytokine analysis showed elevated MIP-1α and MIP-1β in HPV infections, though cytokine profiles may depend on HPV genotypes. These findings underscore the need for research on HPV-microbiome-immune interactions and call for comprehensive HPV-prevention strategies, including vaccines targeting regional HPV types and tailored interventions for HIV-positive populations.

Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

Methylation markers for anal cancer screening: A repeated cross-sectional analysis of people living with HIV, 2015-2016

People living with HIV (PLWH) are at highest risk of anal cancer and will benefit from optimized screening for early disease detection. We compared host DNA methylation markers in high-grade squamous intraepithelial lesions (HSIL) versus samples negative for intraepithelial lesions (NILM) or low-grade intraepithelial lesions (LSIL) in PLWH. We recruited PLWH identifying as male aged ≥18 years undergoing high-resolution anoscopy (HRA) in Seattle, Washington, 2015-2016. Anal brush samples were collected for HPV detection, genotyping, and pyrosequencing methylation (host genes ASCL1, PAX1, FMN2, and ATP10A); clinical data were abstracted from medical records. We assessed associations between methylation and presence and extent of HSIL using generalized estimating equation logistic regression, adjusting for age, CD4 count and HIV viral load. Marker panels using HPV DNA and methylation were also evaluated to predict prevalent HSIL. We analyzed 125 samples from 85 participants (mean age 50.1; standard deviation 11.0 years). ASCL1 (adjusted odds ratio [aOR] per 1 unit increase mean percent methylation: 1.07, 95% CI: 1.01-1.13) and FMN2 (aOR per 1 unit increase mean percent methylation: 1.14, 95% CI: 1.08-1.20) methylation were significantly associated with HSIL versus NILM/LSIL. ASCL1 (aOR: 1.06, 95% CI: 1.01-1.11) and FMN2 (aOR: 1.13, 95% CI: 1.08-1.17) methylation were positively associated with increasing HSIL extent. A panel combining methylation (ASCL1 and FMN2) and HPV DNA (HPV16, HPV18, and HPV31) demonstrated best balance of sensitivity (78.2%) and specificity (73.9%) for HSIL detection compared with methylation or HPV alone. Increasing levels of DNA methylation of ASCL1 and FMN2 were positively associated with HSIL detection in PLWH. Host gene methylation testing shows promise for HSIL screening and triage.

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Host Nuclear Genome Copy Number Variations Identify High-Risk Anal Precancers in People Living With HIV

BACKGROUND

People living with HIV (PLWH) have substantially increased incidence of anal precancer and cancer. There are very little data regarding genomic disturbances in anal precancers among PLWH. In this study, specific chromosomal variants were identified in anal squamous intraepithelial lesions.

METHODS

Overall, 63 anal biopsy specimens (27 low-grade intraepithelial lesions [LSIL] and 36 high-grade intraepithelial lesions [HSIL]) were collected from PLWH obtained as part of anal cancer screening in our NYC-based health system. Data on patient demographics, anal cytological, and high-risk human papillomavirus (HR-HPV) diagnoses were collected. Specimens were tested for a panel of chromosomal alterations associated with HPV-induced oncogenesis using fluorescence in situ hybridization, and analyses compared the associations of these alterations with clinical characteristics.

RESULTS

Gains of 3q26, 5p15, 20q13, and cen7 were detected in 42%, 31%, 31%, and 19% of HSIL compared with 7%, 0%, 4%, and 0% of LSIL, respectively. If at least 1 abnormality was observed, 89% had a 3q26 gain. In lesions with 5p15 gains, 20q13 gains co-occurred in 91% of cases, while cen7 gain only co-occurred with the other 3 alterations. The sensitivity and specificity of any alteration to predict HSIL were 47% (95% CI: 30%-65%) and 93% (95% CI: 76%-99%), respectively.

CONCLUSIONS

Genomic alterations seen in HPV-associated cancers may help distinguish anal LSIL from HSIL. 3q26 amplification may be an early component of anal carcinogenesis, preceding 5p16, 20q13, and/or chr7.

IMPACT

Insights into potential genomic biomarkers for discriminating high-risk anal precancers are shared.

Deep Learning and High-Resolution Anoscopy: Development of an Interoperable Algorithm for the Detection and Differentiation of Anal Squamous Cell Carcinoma Precursors-A Multicentric Study

High-resolution anoscopy (HRA) plays a central role in the detection and treatment of precursors of anal squamous cell carcinoma (ASCC). Artificial intelligence (AI) algorithms have shown high levels of efficiency in detecting and differentiating HSIL from low-grade squamous intraepithelial lesions (LSIL) in HRA images. Our aim was to develop a deep learning system for the automatic detection and differentiation of HSIL versus LSIL using HRA images from both conventional and digital proctoscopes. A convolutional neural network (CNN) was developed based on 151 HRA exams performed at two volume centers using conventional and digital HRA systems. A total of 57,822 images were included, 28,874 images containing HSIL and 28,948 LSIL. Partial subanalyses were performed to evaluate the performance of the CNN in the subset of images acetic acid and lugol iodine staining and after treatment of the anal canal. The overall accuracy of the CNN in distinguishing HSIL from LSIL during the testing stage was 94.6%. The algorithm had an overall sensitivity and specificity of 93.6% and 95.7%, respectively (AUC 0.97). For staining with acetic acid, HSIL was differentiated from LSIL with an overall accuracy of 96.4%, while for lugol and after therapeutic manipulation, these values were 96.6% and 99.3%, respectively. The introduction of AI algorithms to HRA may enhance the early diagnosis of ASCC precursors, and this system was shown to perform adequately across conventional and digital HRA interfaces.

Concordance of Human Papillomavirus Genotypes in Mailed Home-Based Self-Collected Versus Clinician-Collected Anal Swabs Among Sexual and Gender Minority Individuals

BACKGROUND

Home-based self-sampling may be a viable option for anal cancer screening among sexual minority men (SMM). Yet limited research has compared home-based self-collected with clinician-collected anal swabs for human papillomavirus (HPV) genotyping.

METHODS

The Prevent Anal Cancer Self-Swab Study recruited SMM and transgender persons 25 years and over in Milwaukee, WI to participate in an anal cancer screening study. Participants were randomized to a home or clinic arm. Home-based participants were mailed an anal self-sampling kit to complete and return via postal mail. They were also asked to attend a clinic appointment where a clinician collected an anal swab. Swabs were HPV-genotyped using the SPF 10 -LiPA 25 assay. We analyzed 79 paired self and clinician swabs to determine HPV prevalence, percent agreement, and sensitivity and specificity of the mailed home-based anal self-swab to detect HPV genotypes using the clinician-collected swab as the reference.

RESULTS

The median number of days between the home and clinic swab was 19 days (range = 2 to 70). Human papillomavirus was detected in 73.3% of self and 75.0% of clinician anal swabs ( P = 0.99). Prevalence of any HPV, any high-risk HPV, any low-risk HPV, and individual HPV types did not significantly differ between self and clinician anal swabs. Agreement between self and clinician swabs was over 90% for 21 of the 25 HPV genotypes. Mailed home-based self-collected swabs had a sensitivity of 94.1% (95% confidence interval, 82.9-99.0) for detection of high-risk HPV versus clinician-collected sampling.

CONCLUSIONS

Mailed home-based self-collected and clinician-collected anal swabs demonstrated high concordance for HPV genotyping.

Deep Learning in High-Resolution Anoscopy: Assessing the Impact of Staining and Therapeutic Manipulation on Automated Detection of Anal Cancer Precursors

INTRODUCTION

High-resolution anoscopy (HRA) is the gold standard for detecting anal squamous cell carcinoma (ASCC) precursors. Preliminary studies on the application of artificial intelligence (AI) models to this modality have revealed promising results. However, the impact of staining techniques and anal manipulation on the effectiveness of these algorithms has not been evaluated. We aimed to develop a deep learning system for automatic differentiation of high-grade squamous intraepithelial lesion vs low-grade squamous intraepithelial lesion in HRA images in different subsets of patients (nonstained, acetic acid, lugol, and after manipulation).

METHODS

A convolutional neural network was developed to detect and differentiate high-grade and low-grade anal squamous intraepithelial lesions based on 27,770 images from 103 HRA examinations performed in 88 patients. Subanalyses were performed to evaluate the algorithm's performance in subsets of images without staining, acetic acid, lugol, and after manipulation of the anal canal. The sensitivity, specificity, accuracy, positive and negative predictive values, and area under the curve were calculated.

RESULTS

The convolutional neural network achieved an overall accuracy of 98.3%. The algorithm had a sensitivity and specificity of 97.4% and 99.2%, respectively. The accuracy of the algorithm for differentiating high-grade squamous intraepithelial lesion vs low-grade squamous intraepithelial lesion varied between 91.5% (postmanipulation) and 100% (lugol) for the categories at subanalysis. The area under the curve ranged between 0.95 and 1.00.

DISCUSSION

The introduction of AI to HRA may provide an accurate detection and differentiation of ASCC precursors. Our algorithm showed excellent performance at different staining settings. This is extremely important because real-time AI models during HRA examinations can help guide local treatment or detect relapsing disease.

The microbiome as a biomarker of anal precancerous lesions in people with HIV

PURPOSE OF REVIEW

Early detection and treatment of human papillomavirus (HPV)-related anal dysplasia in some high-risk groups can help anal cancer prevention, but new tools to improve diagnostic and risk assessment are needed. Here, we aim to discuss the evidence on the role of the microbiome as a potential biomarker for anal high-grade squamous intraepithelial lesions (HSILs) in people with HIV (PWH).

RECENT FINDINGS

This review covers relevant studies on the links between the microbiome and HPV infection, cervical dysplasia/cancer, and anal HPV disease. It focuses on anal samples and precancerous lesions.

SUMMARY

The review highlights the promising potential of the anal microbiome as a novel biomarker for precancerous lesions in people with HIV, while also discussing limitations and future research needs.

Severe anal intraepithelial neoplasia trends and subsequent invasive anal cancer in the United States

BACKGROUND

Anal intraepithelial neoplasia grade III is a precursor to squamous cell carcinoma of the anus for which rates are nearly 20-fold higher in people with HIV than in the general population in the United States. We describe trends in anal intraepithelial neoplasia grade III diagnosis and risk of squamous cell carcinoma of the anus following anal intraepithelial neoplasia grade III by HIV status and sex.

METHODS

We used data from a population-based linkage between cancer and HIV registries in 11 US states; Puerto Rico; and Washington, DC, during 1996-2019. We identified all individuals with a diagnosis of anal intraepithelial neoplasia grade III and determined their HIV status. We estimated the average annual percentage change of anal intraepithelial neoplasia grade III using Poisson regression stratified by HIV status and sex. We estimated the 5-year cumulative incidence of squamous cell carcinoma of the anus following an anal intraepithelial neoplasia grade III diagnosis stratified by sex, HIV status, and prior AIDS diagnosis.

RESULTS

Among people with HIV, average annual percentage changes for anal intraepithelial neoplasia grade III were 15% (95% confidence interval [CI] = 12% to 17%) per year among females and 12% (95% CI = 11% to 14%) among males. Average annual percentage changes for those without HIV were 8% (95% CI = 7% to 8%) for females and 8% (95% CI = 6% to 9%) for males. Among people with HIV, a prior AIDS diagnosis was associated with a 2.7-fold (95% CI = 2.23 to 3.40) and 1.9-fold (95% CI = 1.72 to 2.02) increased risk of anal intraepithelial neoplasia grade III diagnosis for females and males, respectively. Five-year cumulative incidence of squamous cell carcinoma of the anus following anal intraepithelial neoplasia grade III for people with HIV with a prior AIDS diagnosis were 3.4% and 3.7% for females and males, respectively.

CONCLUSIONS

Rates of anal intraepithelial neoplasia grade III diagnoses have increased since 1996, particularly for people with HIV, likely influenced by increased screening. A prior AIDS diagnosis was strongly associated with risk of anal intraepithelial neoplasia grade III diagnosis.

Screening for precancerous anal lesions linked to human papillomaviruses: French recommendations for clinical practice

In France, about 2000 new cases of anal cancer are diagnosed annually. Squamous cell carcinoma is the most common histological type, mostly occurring secondary to persistent HPV16 infection. Invasive cancer is preceded by precancerous lesions. In addition to patients with a personal history of precancerous lesions and anal cancer, three groups are at very high risk of anal cancer: (i) men who have sex with men and are living with HIV, (ii) women with a history of high-grade squamous intraepithelial lesions (HSILs) or vulvar HPV cancer, and (iii) women who received a solid organ transplant more than 10 years ago. The purpose of screening is to detect HSILs so that they can be treated, thereby reducing the risk of progression to cancer. All patients with symptoms should undergo a proctological examination including standard anoscopy. For asymptomatic patients at risk, an initial HPV16 test makes it possible to target patients at risk of HSILs likely to progress to cancer. Anal cytology is a sensitive test for HSIL detection. Its sensitivity is greater than 80% and exceeds that of proctological examination with standard anoscopy. It is indicated in the event of a positive HPV16 test. In the presence of cytological abnormalities and/or lesions and a suspicion of dysplasia on clinical examination, high-resolution anoscopy is indicated. Performance is superior to that of proctological examination with standard anoscopy. However, this technique is not widely available, which limits its use. If high-resolution anoscopy is not possible, screening by a standard proctological examination is an alternative. There is a need to develop high-resolution anoscopy and triage tests and to evaluate screening strategies.

Anal Cancers in Previously Screened Versus Unscreened Patients: Tumor Stage and Treatment Outcomes

BACKGROUND

Targeted screening programs for patients at high risk for anal squamous-cell carcinoma have been proposed; however, the evidence in support of screening remains unclear.

OBJECTIVE

This study aimed to determine whether screening high-risk patients (predominantly those living with HIV) detected squamous-cell carcinoma at an earlier stage compared to the routine practice of not screening.

DESIGN

This is a cohort study.

SETTINGS

This study was conducted at a quaternary care center in Canada.

PATIENTS

Included patients were at least 18 years old with a pathologic diagnosis of invasive anal squamous-cell carcinoma between 2002 and 2022.

INTERVENTIONS

Patients diagnosed through a high-risk screening program were compared to those who did not undergo screening.

MAIN OUTCOME MEASURES

The primary outcome was clinical stage at presentation, categorized as T1N0M0 vs other. Secondary outcomes included treatments received, treatment failure, and overall survival.

RESULTS

A total of 612 patients with anal squamous-cell carcinoma were included, with 26 of those patients diagnosed through a screening program. Patients with screen-detected cancers had greater odds of presenting with T1N0M0 tumors compared to unscreened patients (18 [69.2%] vs 84 [14.3%]; adjusted OR 9.95; 95% CI, 3.95-25.08). A propensity score-matched sensitivity analysis found similar results (OR 11.13; 95% CI, 4.67-26.52). Screened patients had greater odds of treatment with wide local excision alone, as opposed to any combination of chemotherapy, radiation therapy, and surgery (3 [12.5%] vs 18 [3.2%]; OR 4.38; 95% CI, 1.20-16.04). There were no statistically significant differences in treatment failure or overall survival between groups.

LIMITATIONS

The small number of screened patients limits the power of the analysis.

CONCLUSIONS

Screening for anal squamous-cell carcinoma among high-risk populations detects cancers at an earlier stage. Patients with screen-detected cancers also had a greater likelihood of being candidates for wide local excision alone, which may have spared them the morbidity associated with chemoradiotherapy or abdominoperineal resection. See Video Abstract.

CNCERES DE ANO EN PACIENTES PREVIAMENTE DETECTADOS POR CRIBADO VERSUS NO DETECTADOS ESTADIO DEL TUMOR Y RESULTADOS DEL TRATAMIENTO

ANTECEDENTES:Se han propuesto programas de cribado dirigidos a pacientes con alto riesgo de carcinoma anal de células escamosas; sin embargo, la evidencia a favor de la detección sigue sin estar clara.OBJETIVO:Este estudio tuvo como objetivo determinar si el cribado de pacientes de alto riesgo (predominantemente aquellos que viven con el VIH) detectó el carcinoma de células escamosas en una etapa más temprana en comparación con la práctica habitual de no cribado.DISEÑO:Este es un estudio de cohortes.CONFIGURACIÓN:Este estudio se realizó en un centro de atención cuaternaria en Canadá.PACIENTES:Los pacientes incluidos tenían al menos 18 años con un diagnóstico patológico de carcinoma de células escamosas anal invasivo entre 2002 y 2022.INTERVENCIONES:Los pacientes diagnosticados mediante un programa de cribado de alto riesgo se compararon con aquellos que no se sometieron a cribado.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el estadio clínico en la presentación, categorizado como T1N0M0 versus otro. Los resultados secundarios incluyeron los tratamientos recibidos, el fracaso del tratamiento y la supervivencia general.RESULTADOS:Se incluyeron un total de 612 pacientes con carcinoma anal de células escamosas, con 26 de esos pacientes diagnosticados a través de un programa de cribado. Los pacientes con cánceres detectados mediante cribado tenían mayores probabilidades de presentar tumores T1N0M0 en comparación con los pacientes no cribados (18 [69.2%] frente a 84 [14.3%]; razón de probabilidad ajustada 9.95; intervalo de confianza del 95 % 3.95 -25.08). Un análisis de sensibilidad emparejado por puntaje de propensión encontró resultados similares (odds ratio 11.13; intervalo de confianza del 95% 4.67 -26.52; p < 0.001). Los pacientes examinados tenían mayores probabilidades de recibir tratamiento con escisión local amplia sola, en comparación con cualquier combinación de quimioterapia, radiación y cirugía (3 [12.5%] frente a 18 [3.2%]; razón de probabilidad 4.38; intervalo de confianza del 95 % 1.20 -16.04). No hubo diferencias estadísticamente significativas en el fracaso del tratamiento o la supervivencia global entre los grupos.LIMITACIONES:El pequeño número de pacientes evaluados limita el poder del análisis.CONCLUSIONES:La detección del carcinoma anal de células escamosas entre las poblaciones de alto riesgo detecta los cánceres en una etapa más temprana. Los pacientes con cánceres detectados mediante cribado también tenían una mayor probabilidad de ser candidatos para una escisión local amplia sola, lo que puede haberles evitado la morbilidad asociada con la quimiorradioterapia o la resección abdominoperineal. (Traducción --Dr. Aurian Garcia Gonzalez ).

An Alternative to Cytology in Triaging Cisgender Men and Transgender Women With HIV for High-Resolution Anoscopy

OBJECTIVES

To evaluate high-risk human papillomavirus testing (hrHPV) as an alternative for anal cytology in screening for high-grade anal neoplasia (AIN2-3) among males with HIV. To identify predictive risk factors for AIN2-3 and develop a clinical tool to triage males with HIV for high-resolution anoscopy (HRA) without cytology.

DESIGN

Retrospective cohort study of 199 adult cisgender men and transgender women with HIV referred to an anal neoplasia clinic in the Southeastern United States between January 2018 and March 2021.

METHODS

Each subject underwent cytology, hrHPV, and HRA. Clinical and sociodemographic risk factors were collected for each subject. Significant risk factors for AIN2-3 were identified using logistic regression, and a triage tool incorporating these factors was developed. Screening test characteristics were calculated for cytology with and without adjunct hrHPV, hrHPV alone, and the triage tool.

RESULTS

In multivariate analysis, significant predictors of AIN2-3 were hrHPV positivity (odds ratio [OR] = 11.98, CI = 5.58-25.69) and low CD4 count (OR = 2.70, CI = 1.20-6.11). There was no significant difference in positive or negative predictive values among the tool, stand-alone hrHPV, and anal cytology with adjunct hrHPV. Sensitivity and specificity were not significantly different for stand-alone or adjunctive hrHPV testing. Compared with cytology, stand-alone hrHPV and the novel triage tool reduced unnecessary HRA referrals by 65% and 30%, respectively.

CONCLUSIONS

Stand-alone hrHPV would have missed 11 of 74 AIN2-3 and generated 74 fewer unnecessary HRAs than current cytology-based screening patterns, which led to 115 unnecessary HRAs in our cohort. We propose triaging those with low CD4 count, hrHPV positivity, and/or smoking history for HRA.

Optical imaging for screening and early cancer diagnosis in low-resource settings

Low-cost optical imaging technologies have the potential to reduce inequalities in healthcare by improving the detection of pre-cancer or early cancer and enabling more effective and less invasive treatment. In this Review, we summarise technologies for in vivo widefield, multi-spectral, endoscopic, and high-resolution optical imaging that could offer affordable approaches to improve cancer screening and early detection at the point-of-care. Additionally, we discuss approaches to slide-free microscopy, including confocal imaging, lightsheet microscopy, and phase modulation techniques that can reduce the infrastructure and expertise needed for definitive cancer diagnosis. We also evaluate how machine learning-based algorithms can improve the accuracy and accessibility of optical imaging systems and provide real-time image analysis. To achieve the potential of optical technologies, developers must ensure that devices are easy to use; the optical technologies must be evaluated in multi-institutional, prospective clinical tests in the intended setting; and the barriers to commercial scale-up in under-resourced markets must be overcome. Therefore, test developers should view the production of simple and effective diagnostic tools that are accessible and affordable for all countries and settings as a central goal of their profession.

Deployment and assessment of a deep learning model for real-time detection of anal precancer with high frame rate high-resolution microendoscopy

Anal cancer incidence is significantly higher in people living with HIV as HIV increases the oncogenic potential of human papillomavirus. The incidence of anal cancer in the United States has recently increased, with diagnosis and treatment hampered by high loss-to-follow-up rates. Novel methods for the automated, real-time diagnosis of AIN 2+ could enable "see and treat" strategies, reducing loss-to-follow-up rates. A previous retrospective study demonstrated that the accuracy of a high-resolution microendoscope (HRME) coupled with a deep learning model was comparable to expert clinical impression for diagnosis of AIN 2+ (sensitivity 0.92 [P = 0.68] and specificity 0.60 [P = 0.48]). However, motion artifacts and noise led to many images failing quality control (17%). Here, we present a high frame rate HRME (HF-HRME) with improved image quality, deployed in the clinic alongside a deep learning model and evaluated prospectively for detection of AIN 2+ in real-time. The HF-HRME reduced the fraction of images failing quality control to 4.6% by employing a high frame rate camera that enhances contrast and limits motion artifacts. The HF-HRME outperformed the previous HRME (P < 0.001) and clinical impression (P < 0.0001) in the detection of histopathologically confirmed AIN 2+ with a sensitivity of 0.91 and specificity of 0.87.

Anal Cancer and Anal Cancer Screening

This chapter provides an overview of anal cancer and contemporary approaches for anal precancer detection, beginning with a discussion of the biology and natural history of anal squamous cell carcinoma, the predominant human papillomavirus -associated histologic subtype of anal cancer. This section is followed by a description of the epidemiology of anal cancer, including trends in incidence and mortality, a discussion of populations with elevated risk for anal cancer and an overview of associated risk factors. The remainder of the chapter provides the most up-to-date evidence on tools and approaches for anal cancer prevention, screening, and early detection; including, the role of human papillomavirus vaccination for primary prevention; anal cytology, high resolution anoscopy and novel biomarkers for secondary prevention; and digital anal-rectal examination for early detection.

DNA high-risk HPV, mRNA HPV and P16 tests for diagnosis of anal cancer and precursor lesions: a systematic review and meta-analysis

Background

Anal cancer prevention has two critical points: the incidence rate is several fold higher for some groups, such as people living with human immunodeficiency virus (HIV) and men who have sex with men (MSM), and there is not a well-defined guideline for its screening. This systematic review evaluates the accuracy of DNA HRHPV (high-risk human papillomavirus), mRNA HPV, DNA HPV16 isolated and p16 staining biomarkers in anal canal smears for identifying anal intraepithelial neoplasia (AIN) 2 or 3, summarised as anal high-grade squamous intraepithelial lesions (aHSIL), and cancer.

Methods

We searched the MEDLINE, Cochrane Library and Embase electronic databases as well as Grey literature to identify eligible papers published up to 31st July 2022. This systematic review and meta-analysis included observational studies comparing biomarker tests to histopathology after HRA (High-resolution Anoscopy) as a reference standard. We (ACM, TF) analysed studies in which patients of both sexes were screened for anal cancer using DNA HRHPV, mRNA HPV, DNA HPV16 and/or p16 biomarkers. The analysis was performed in pairs, for instance AIN2 or worse (AIN2+) vs. AIN1, HPV infection and normal (AIN1-). PROSPERO CRD42015024201.

Findings

We included 21 studies with 7445 patients. DNA HR HPV showed a higher sensitivity 92.4% (95% CI 84.2-96.5), specificity 41.7% (95% CI 33.9-44.9) and AUC 0.67, followed by the mRNA HPV test, with a sensitivity 77.3% (95% CI 73.2%-80.9%), specificity 61.9% (95% CI 56.6-66.9) and AUC 0.78. DNA HPV16 showed higher specificity 71.7% (95% CI 55.3-83.8), followed by p16 test, 64.1% (95% CI 51.0-75.4); Sensitivity of DNA HPV16 was 53.3% (95% CI 35.4-70.3) and AUC 0.69, while p16 had a sensitivity of 68.8% (95% CI 47.9-84.1) and AUC 0.74. Subgroup analysis of MSM with HIV, with 13 studies and 5123 patients, showed similar accuracy, with a bit higher sensitivities and lower specificities. Considering the measure of the total between-study variability, mRNA HPV tests showed the smallest area of the 95% prediction ellipse, 6.0%, influenced by the low logit sensitivity, 0.011. All other groups of tests exceed 50% prediction ellipse area, which represent a high heterogeneity.

Interpretation

Our findings suggested that DNA HR HPV can be a useful tool for screening for aHSIL and anal cancer if followed by biomarker with a higher specificity. As an isolated test, mRNA HPV had better performance.

Funding

There was no funding source for this study.

Microbiome-derived cobalamin and succinyl-CoA as biomarkers for improved screening of anal cancer

Human papillomavirus can cause preinvasive, high-grade squamous intraepithelial lesions (HSILs) as precursors to cancer in the anogenital area, and the microbiome is suggested to be a contributing factor. Men who have sex with men (MSM) living with human immunodeficiency virus (HIV) have a high risk of anal cancer, but current screening strategies for HSIL detection lack specificity. Here, we investigated the anal microbiome to improve HSIL screening. We enrolled participants living with HIV, divided into a discovery (n = 167) and validation cohort (n = 46), and who were predominantly (93.9%) cisgender MSM undergoing HSIL screening with high-resolution anoscopy and anal biopsies. We identified no microbiome composition signatures associated with HSILs, but elevated levels of microbiome-encoded proteins producing succinyl coenzyme A and cobalamin were significantly associated with HSILs in both cohorts. Measurement of these candidate biomarkers alone in anal cytobrushes outperformed anal cytology as a diagnostic indicator for HSILs, increasing the sensitivity from 91.2% to 96.6%, the specificity from 34.1% to 81.8%, and reclassifying 82% of false-positive results as true negatives. We propose that these two microbiome-derived biomarkers may improve the current strategy of anal cancer screening.

Anal Cancer and Anal Intraepithelial Neoplasia Risk among Patients Treated for HPV-Related Gynecological Diseases-A Systematic Review

BACKGROUND

The most important causative agent of neoplasms in the anogenital area is the human papillomavirus (HPV). Due to the anatomical proximity of the genital and anus area and the ease with which HPV infection is transmitted, it seems that patients after the treatment of HPV-related gynecological diseases may have an increased risk of developing a second HPV-related neoplasm anal cancer. The aim of this study was to determine the risk of anal intraepithelial neoplasia (AIN) and anal cancer (AC) among patients after the treatment of HPV-related gynecological diseases.

METHODS

We conducted a comprehensive review of the available literature from multiple databases. The study was performed following Cochrane Reviewers' Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 guidelines. Moreover, we assessed the quality of each study using QUADAS-2.

RESULTS

Twenty-five studies were included in the final analysis. Patients after the treatment of HPV-related gynecological diseases have a significantly higher risk of AC (mean standardized incidence ratio (SIR) = 5.387, mean incidence risk (IR) = 0.096%, mean IR per 100,000 person-years = 10.37) and AIN (mean IR = 23.683%) compared to the population risk.

CONCLUSIONS

patients with HPV-related gynecological diseases should constitute a group for which an appropriate primary and secondary screening for AC should be introduced.

Rectal Bleeding in the Clinic

Anal cancer is a rare malignancy with an estimated 8,580 new cases each year in the USA where hematochezia, a common condition, is often the initial presenting sign. We describe a 51-year-old woman who presented with painful hematochezia, with a delayed diagnosis of anal cancer in the setting of missed and misdiagnosed digital rectal exams in an otherwise low-risk patient. This case highlights the importance of maintaining a broad differential diagnosis for hematochezia and the utility of thorough physical exams.

Multi-institutional 10-year retrospective review of amoeba diagnosed on cytologic evaluation of anal pap tests: what is the significance?

INTRODUCTION

Intestinal amoebae are usually transmitted via ingestion of amoebic cysts in fecally contaminated water or food. However, other modes of transmission include sexual contact through anal-oral sex. While the primary role of anal cytology is the detection of anal cancer and precursor lesions, organisms can also be identified. Despite this, assessment of the clinical significance of cytologic identification of amoebae is lacking in the literature.

MATERIALS AND METHODS

A 10-year retrospective review of the pathology archives of 2 institutions in Boston, Massachusetts was conducted. Anal Pap tests that identified amoeba were reviewed and correlated with the medical records for investigation into clinical parameters and patient management.

RESULTS

A total of 46 cases were identified between the 2 sites. The majority of patients were male (95.7%) and endorsed having sex with men (84.8%). Only a minority endorsed recent travel (6.5%). Most of the patients were also HIV (human immunodeficiency virus)-positive (71.1%) with all of these patients being well-controlled on antiretroviral therapy. Most patients were asymptomatic (87.0%). On review of the anal Pap tests, the average organism number per case was 35.4. In the majority of cases, follow-up microbiology testing for confirmation and/or speciation was not performed (89.1%) and were not treated (93.5%).

CONCLUSIONS

While identification of amoeba is possible on anal cytology, the clinical significance remains unclear as most patients were asymptomatic and not treated in this series. Ultimately, the clinical setting likely plays an important role in determination of management.

Comparison of anal pre-cancer screening strategies among men who have sex with men

PURPOSE

Comparison of anal pre-cancer screening strategies in men who have sex with men (MSM).

METHODS

MSM in the Multicenter AIDS Cohort Study underwent repeated anal cytology (aCyt), oncogenic human papillomavirus (oncHPV) testing. A subset received High-Resolution Anoscopy (HRA). We evaluated three screening strategies for their ability to predict anal histological High-Grade Squamous Intraepithelial lesion (HSIL): single aCyt, sequential aCyt, and oncHPV co-testing. Multivariable logistic regression models evaluated risk of HSIL among participants undergoing HRA within 5 years of screening. Sensitivity and specificity were estimated among participants with HRA, and results corrected for verification bias using weighted generalized estimating equations.

RESULTS

There were 1426 MSM with aCyt screening (48% people with HIV [PWH]) and 428 that underwent HRA. Median age was 57 years, 14% of PWH had CD4< 350 cells/mm3. HSIL probability was higher in MSM with one (39%, p < 0.01) or two abnormal aCyt results (46%, p < 0.01), versus those with normal aCyt (23-24%). Among men with abnormal aCyt, men with oncHPV+ had significantly higher risk than those who were oncHPV- (47% vs. 16%, p < 0.01). Specificity was modest with single aCyt+ (50%) but increased with sequential aCyt+ (79%) or oncHPV+ (67%). Sensitivity was high with single oncHPV+ (88%), moderate with single aCyt+ (66%) and oncHPV+ co-testing (61%), and low with sequential aCyt+ (39%). After correcting for potential verification bias, specificity increased and sensitivity decreased, but inferences were similar.

CONCLUSION

None of the screening strategies evaluated had both sufficient specificity and sensitivity to warrant routine widespread use.

Automated In Vivo High-Resolution Imaging to Detect Human Papillomavirus-Associated Anal Precancer in Persons Living With HIV

INTRODUCTION

In the United States, the effectiveness of anal cancer screening programs has been limited by a lack of trained professionals proficient in high-resolution anoscopy (HRA) and a high patient lost-to-follow-up rate between diagnosis and treatment. Simplifying anal intraepithelial neoplasia grade 2 or more severe (AIN 2+) detection could radically improve the access and efficiency of anal cancer prevention. Novel optical imaging providing point-of-care diagnoses could substantially improve existing HRA and histology-based diagnosis. This work aims to demonstrate the potential of high-resolution microendoscopy (HRME) coupled with a novel machine learning algorithm for the automated, in vivo diagnosis of anal precancer.

METHODS

The HRME, a fiber-optic fluorescence microscope, was used to capture real-time images of anal squamous epithelial nuclei. Nuclear staining is achieved using 0.01% wt/vol proflavine, a topical contrast agent. HRME images were analyzed by a multitask deep learning network (MTN) that computed the probability of AIN 2+ for each HRME image.

RESULTS

The study accrued data from 77 people living with HIV. The MTN achieved an area under the receiver operating curve of 0.84 for detection of AIN 2+. At the AIN 2+ probability cutoff of 0.212, the MTN achieved comparable performance to expert HRA impression with a sensitivity of 0.92 ( P = 0.68) and specificity of 0.60 ( P = 0.48) when using histopathology as the gold standard.

DISCUSSION

When used in combination with HRA, this system could facilitate more selective biopsies and promote same-day AIN2+ treatment options by enabling real-time diagnosis.

Development of a multivariable prediction model for anal high-grade squamous intraepithelial lesions in persons living with HIV in Puerto Rico: a cross-sectional study

Background

Persons living with HIV (PLWH) are at high risk of developing anal high-grade squamous intraepithelial lesions (HSIL). We aimed to develop a prediction model for anal HSIL based on individual characteristics of PLWH.

Methods

Cross-sectional study of PLWH aged ≥21 years who attended the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center from 2016 to 2022. The primary outcome was biopsy-confirmed anal HSIL. For each sex, relations between potential predictors and HSIL were examined using univariate (ULRM) and multivariable (MLRM) logistic regression models. Risk modelling was performed with MLRM and validated with bootstrapping techniques. The area under the ROC Curves (AUC) was estimated with 95% CI.

Findings

HSIL was detected among 45.11% of patients, 68.48% were males, and 59.42% were ≥45 aged. Multivariable analysis showed that, in women, the only significant predictor for HSIL was having a previous abnormal anal cytology (p = 0.01). In men, significant predictors for HSIL were having a previous abnormal anal cytology (p < 0.001) and a history of infection with any gonorrhoea (p = 0.002). Other suggestive predictors for HSIL among women were obesity and smoking. No association between smoking and HSIL among men was observed (p < 0.05). The AUC estimated among women (0.732, 95% CI: 0.651-0.811) was higher than in men (0.689, 95% CI: 0.629-0.748).

Interpretation

Our results support that the inclusion of individual characteristics into the prediction model will adequately predict the presence of HSIL in PLWH.

Funding

This work was supported by the NCI (Grants #U54CA096297, #R25CA240120), the NIGMS (Grant #U54GM133807), and the NIMHD (Grant #U54MD007587).

Incidence of abnormal anal cytology in HIV-infected and HIV-uninfected men who have sex with men

INTRODUCTION

Anal cytology is used in the prevention of anal cancer, which disproportionally affects men who have sex with men (MSM). Data on the incidence of cytologic abnormalities in these individuals are scant.

METHODS

MSM with baseline negative anal cytology and at least one further adequate cytology were included. Incidence rate for positive atypical squamous cells of undetermined significance (ASC-US+) was calculated. Kaplan-Meier curves were compared by log-rank test according to HIV status, baseline high-risk human papillomavirus (HPV) (high-risk HPV-negative, HPV16-positive, other high-risk HPV-positive [non-HPV16]) and high-risk HPV persistence (positive from baseline to the first ASC-US+ or last visit for those who remained cytologically negative). Cox univariate and multivariate analyses were performed.

RESULTS

A total of 250 MSM were included: 52/153 (34.0%) HIV-uninfected MSM had an ASC-US+ report at follow-up (incidence: 13.1 × 100 person-years; 95% CI, 9.8-17.2); 48/97 (49.5%) HIV-infected MSM developed cytologic abnormalities (incidence: 16.0 × 100 person-years; 95% CI, 11.8-21.2). ASC-US+ incidence in HIV-uninfected and HIV-infected MSM did not differ significantly (p = .32). Kaplan-Meier curves did not differ significantly according to baseline high-risk HPV. Differences were significant between those with and without persistent high-risk HPVs, both among HIV-uninfected (p = .03) and HIV-infected MSM (p = .008). Age (adjusted hazard ratio [aHR], 0.98; 95% CI, 0.96-0.99), high-risk HPV persistence (aHR, 1.57; 95% CI, 1.02-2.39), and condomless receptive anal sex (aHR, 1.99; 95% CI, 1.31-3.03) were predictors for incident ASC-US+.

CONCLUSIONS

Despite the limited number of subjects, in our study HIV-uninfected and HIV-infected MSM have a similar ASC-US+ incidence. Occurrence of ASC-US+ was significantly affected by age, high-risk HPV persistence, and condomless receptive anal sex. The assessment of HPV persistence might identify those MSM at higher risk for anal lesions.

A systematic review and meta-analysis of cytology and HPV-related biomarkers for anal cancer screening among different risk groups

To inform optimal approaches for detecting anal precancers, we performed a systematic review and meta-analysis of the diagnostic accuracy of anal cancer screening tests in different populations with elevated risk for anal cancer. We conducted a literature search of studies evaluating tests for anal precancer and cancer (anal intraepithelial neoplasia grade 2 or worse, AIN2+) published between January 1, 1997 to September 30, 2021 in PubMed and Embase. Titles and abstracts were screened for inclusion and included articles underwent full-text review, data abstraction and quality assessment. We estimated the prevalence of AIN2+ and calculated summary estimates and 95% confidence intervals (CI) of test positivity, sensitivity and specificity and predictive values of various testing strategies, overall and among population subgroups. A total of 39 articles were included. The prevalence of AIN2+ was 20% (95% CI, 17-29%), and ranged from 22% in men who have sex with men (MSM) living with HIV to 13% in women and 12% in MSM without HIV. The sensitivity and specificity of cytology and HPV testing were 81% and 62% and 92% and 42%, respectively, and 93% and 33%, respectively for cytology and HPV co-testing. AIN2+ risks were similar among those testing positive for cytology, HPV, or co-testing. Limited data on other biomarkers (HPV E6/E7 mRNA and p16/Ki-67 dual stain), suggested higher specificity, but lower sensitivity compared with anal cytology and HPV. Our findings provide important evidence for the development of clinical guidelines using anal cytology and HPV testing for anal cancer screening.

Prevalence of oral and anal human papillomavirus infection in Czech predominantly Human immunodeficiency virus-positive men having sex with men - data from a previously unreported population

Background: HIV-positive men who have sex with men (MSM) are more likely to experience human papillomavirus (HPV) infection. The persistent HPV infection is the major factor in the development of anal and oropharyngeal neoplasms. Data on the prevalence of anal and oral HPV in MSM are almost absent from the countries of Central and Eastern Europe. We conducted a cross-sectional study focused on the prevalence of oral and anal HPV infections and the relationship between current anal and oral HPV intrapersonal infection in a Czech population of predominantly HIV-positive MSM. Methods: Oral gargle and anal swab samples from 205 predominantly HIV-positive MSM from the Czech Republic were analysed for HPV infection using PCR. Selected sociodemographic and clinical data were correlated with HPV detection using generalized linear models and multivariate analysis. Results: HPV infection was detected in 183 (96.8%) anal and 48 (23.6%) oral samples. The most common type of HR-HPV was HPV16 in both anal (25.4%) and oral (2.5%) samples. Multiple anal HPV infections and the presence of vaccine-targeted HR-HPV types were significantly correlated with abnormal anal cytology and HIV status. Conclusion: The prevalence of anal HPV infection in Czech predominantly HIV-positive MSM ranks among the highest reported, while oral HPV prevalence is consistent with MSM populations. Minimal overlap of oral and anal HPV types within a patient was observed.

Biomarkers in Anal Cancer: Current Status in Diagnosis, Disease Progression and Therapeutic Strategies

Squamous cell carcinoma of the anal canal (SCCA) is a rare neoplasm, but with rising incidence rates in the past few decades; it is etiologically linked with the human papillomavirus (HPV) infection and is especially prevalent in immunocompromised patients, mainly those infected with HIV. Fluoropyrimidine-based chemoradiotherapy remains the cornerstone of the treatment of non-metastatic disease, but the locally advanced disease still presents high rates of disease recurrence and systemic therapy of SCCA is an unmet clinical need. Despite sharing common molecular aspects with other HPV-related malignancies, such as cervical and head and neck cancers, SCCA presents specific epigenomic, genomic, and transcriptomic abnormalities, which suggest that genome-guided personalized therapies should be specifically designed for this disease. Actionable mutations are rare in SCCA and immune checkpoint inhibition has not yet been proven useful in an unselected population of patients. Therefore, advances in systemic therapy of SCCA will only be possible with the identification of predictive biomarkers and the subsequent development of targeted therapies or immunotherapeutic approaches that consider the unique tumor microenvironment and the intra- and inter-tumoral heterogeneity. In the present review, we address the molecular characterization of SCCA and discuss potential diagnostic, predictive and prognostic biomarkers of this complex and challenging disease.

Treatment of Anal High-Grade Squamous Intraepithelial Lesions to Prevent Anal Cancer

BACKGROUND

The incidence of anal cancer is substantially higher among persons living with the human immunodeficiency virus (HIV) than in the general population. Similar to cervical cancer, anal cancer is preceded by high-grade squamous intraepithelial lesions (HSILs). Treatment for cervical HSIL reduces progression to cervical cancer; however, data from prospective studies of treatment for anal HSIL to prevent anal cancer are lacking.

METHODS

We conducted a phase 3 trial at 25 U.S. sites. Persons living with HIV who were 35 years of age or older and who had biopsy-proven anal HSIL were randomly assigned, in a 1:1 ratio, to receive either HSIL treatment or active monitoring without treatment. Treatment included office-based ablative procedures, ablation or excision under anesthesia, or the administration of topical fluorouracil or imiquimod. The primary outcome was progression to anal cancer in a time-to-event analysis. Participants in the treatment group were treated until HSIL was completely resolved. All the participants underwent high-resolution anoscopy at least every 6 months; biopsy was also performed for suspected ongoing HSIL in the treatment group, annually in the active-monitoring group, or any time there was concern for cancer.

RESULTS

Of 4459 participants who underwent randomization, 4446 (99.7%) were included in the analysis of the time to progression to cancer. With a median follow-up of 25.8 months, 9 cases were diagnosed in the treatment group (173 per 100,000 person-years; 95% confidence interval [CI], 90 to 332) and 21 cases in the active-monitoring group (402 per 100,000 person-years; 95% CI, 262 to 616). The rate of progression to anal cancer was lower in the treatment group than in the active-monitoring group by 57% (95% CI, 6 to 80; P = 0.03 by log-rank test).

CONCLUSIONS

Among participants with biopsy-proven anal HSIL, the risk of anal cancer was significantly lower with treatment for anal HSIL than with active monitoring. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT02135419.).

A novel "signal on-off-super on" sandwich-type aptamer sensor of CRISPR-Cas12a coupled voltage enrichment assay for VEGF detection

Vascular endothelial growth factor (VEGF) plays an important role in atherosclerosis, and the detection of VEGF is critical for the prevention, monitoring, and diagnosis of cardiovascular diseases. Here, a novel "signal on-off-super on" sandwich-type aptamer sensor with a triple signal amplification strategy was developed for the first time. Based on the capture aptamer was labeled with methylene blue (MB) on the internal bases, clustered regularly interspaced short palindromic repeats (CRISPR)-Cas12a-coupled voltage enrichment was used to amplify the electrochemical signal. To improve the analytical performance of the aptamer sensor, gold nanoparticles@Ti₃C₂T_x-Mxene (AuNPs@Ti₃C₂T_x-Mxene) were synthesized through the electrodeposition of AuNPs on the Ti₃C₂T_x-Mxene surface, providing active sites for the immobilization of the aptamer and amplifying the electrochemical signals. The excellent trans-cleavage activity of the CRISPR-Cas12a system was harnessed to cleave signal probes. The cleaved signal probes were enriched using an electrochemical signal instead of complicated target amplification steps before detection. Hence, we report a simplified detection process for amplifying electrochemical signals. Under optimal conditions, the aptamer sensor exhibited high sensitivity, acceptable stability, and reproducibility with a wide linear range from 1 pM to 10 μM (R² = 0.9917) and an ultralow detection limit of 0.33 pM (S/N = 3). Therefore, we propose a novel strategy of CRISPR-Cas12a-based protein detection that opens a new window for the diagnostic applications of various biomarkers.

Impact of HIV on Anal Squamous Cell Carcinoma Rates in the United States, 2001-2015

BACKGROUND

Incidence of anal squamous cell carcinoma (SCC) has increased in the U.S. Persons living with HIV (PLWH) have an elevated risk of anal SCC, and changes in the number of anal SCCs among PLWH may have influenced general population trends.

METHODS

Data were obtained from a linkage of HIV and cancer registries in 12 U.S. regions. The proportion of anal SCCs occurring among PLWH was estimated by sex, age group and race and ethnicity. To assess the impact of anal SCCs among PLWH on general population trends, annual percentage changes (APCs) in incidence rates including and excluding anal SCCs among PLWH were estimated.

RESULTS

Between 2001-2015, 14.5% of 16,110 anal SCC diagnoses occurred in PLWH. In 2013-2015, 33% of anal SCCs among men occurred in PLWH, but only 3% among women. The proportion of anal SCCs among PLWH was highest among 20-49-year-olds and Black and Hispanic individuals. General population anal SCC trends among men were strongly influenced by cases among PLWH: rates increased 4.6%/year [95% confidence interval (CI): 1.4%, 8.0%] from 2001-2009 followed by a non-significant decline (APC: -2.7%/year [95%CI: -7.1, 2.0%]) from 2009-2015, but without anal SCCs among PLWH, rates were stable (APC: 0.7%, [95%CI: -0.8%-2.3%]). Anal SCC rates among women increased 3.8%/year (95%CI 3.2%-4.4%) during 2001-2012 and then declined non-significantly (APC=-3.8; 95%CI -6.9, -0.6), and anal SCCs among PLWH had little impact on these trends.

CONCLUSION

During 2001-2015, anal SCCs among PLWH contributed strongly to changes in incidence trends in the general U.S. population among men, but not women.

Detection of Circulating HPV16 DNA as a Biomarker for Cervical Cancer by a Bead-Based HPV Genotyping Assay

Human papillomavirus (HPV) circulating tumor DNA (HPV ctDNA) was proposed as a biomarker for the detection and disease monitoring of HPV-related cancers. One hundred eighty plasma samples obtained from women diagnosed with HPV16-positive cervical cancer (CC) (n = 100), HPV16-positive premalignant lesions (cervical intraepithelial neoplasia grade 3 [CIN3]) (n = 20), and HPV DNA-negative controls (n = 60) were randomly selected from the archives for evaluating the performance of a bead-based HPV genotyping assay (E7 type-specific multiplex genotyping assay [E7-MPG]) in detecting HPV16 ctDNA. The performance of the E7-MPG was compared with those of DNA detection by droplet digital PCR (ddPCR) and detection of HPV16 E6 antibodies evaluated in an independent study. Internal controls to assess DNA quality were included in the molecular assays, i.e., beta-globin and ESR1, respectively. The sensitivity and specificity of E7-MPG and/or E6 antibodies to detect HPV16-positive CCs were evaluated. HPV16 ctDNA was detected using the E7-MPG in 42.3% of all plasma samples and in 74.7% of plasma samples from HPV16-positive CC cases. The validation of E7-MPG data by ddPCR showed that the sensitivity of the E7-MPG test for HPV16-positive CC detection was higher than that of ddPCR (74.7% versus 63.1%; P < 0.001). When both HPV16 ctDNA and E6 antibodies were considered, the sensitivity for HPV16-positive CC detection increased from 74.7% to 86.1%, while the specificity was unchanged at 97.8%. The performance of E7-MPG for the detection of HPV16 ctDNA appears to be at least as sensitive as that of ddPCR, offering an additional tool for ctDNA detection of HPV16-positive CC. The use of an additional blood marker of HPV infection, such as E6 antibodies, further improved the detection of CC. IMPORTANCE The validity of HPV ctDNA as a marker of HPV-driven cancers has been previously reported. Herein we validated an alternative to ddPCR for HPV16 ctDNA detection, using a bead-based HPV genotyping assay that offers the potential advantage of reducing the cost of clinical management due to the multiplex capability of the test, thus facilitating its use in clinical settings. In addition, we analyzed HPV ctDNA in the context of E6 antibodies as an additional HPV marker. The HPV16 ctDNA biomarker appeared to be highly specific and, to a lesser extent, sensitive for the detection of CC, mainly indicated for those at an advanced tumor stage. In this proof-of-principle study, E6 antibodies were mainly detected in early tumor stages of CC, while HPV ctDNA was mainly positive at advanced tumor stages.

Automated evaluation of p16/Ki-67 dual stain cytology as a biomarker for detection of anal precancer in MSM living with HIV

BACKGROUND

Human papillomavirus (HPV)-related biomarkers such as p16/Ki-67 "dual stain" (DS) cytology have shown promising clinical performance for anal cancer screening. Here, we assessed the performance of automated evaluation of DS cytology to detect anal precancer in men who have sex with men (MSM) living with human immunodeficiency virus (HIV).

METHODS

We conducted a cross-sectional analysis of 320 MSM with HIV undergoing anal cancer screening and high-resolution anoscopy (HRA) between 2009-2010. We evaluated the performance of automated DS based on a deep-learning classifier compared to manual DS evaluation to detect anal intraepithelial neoplasia (AIN) grades 2 and 3 (AIN2+) and AIN3. We evaluated different DS-positive cell thresholds quantified by the automated approach and modeled its performance compared to other screening strategies in a hypothetical population of MSM with HIV.

RESULTS

Automated DS had significantly higher specificity (50.9% vs. 42.2%, p=0.0004) and similar sensitivity (93.2% vs. 92.1%) for detection of AIN2+ compared to manual DS cytology. HPV testing with automated DS triage was significantly more specific (56.5% vs. 50.9%, p=0.0003) with the same sensitivity (93.2%) compared to automated DS alone. In a modeled analysis assuming a 20% AIN2+ prevalence, automated DS detected the most precancers compared to manual DS and anal cytology (186,184, and 162, respectively) and had the lowest HRA referral per AIN2+ detected (3.1,3.5, and 3.3, respectively).

CONCLUSIONS

Compared to manual evaluation, automated DS cytology detects the same number of precancers with lower HRA referral.

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.

Provider Preferences for Anal Cancer Prevention Screening: Results of the International Anal Neoplasia Society Survey

Objective

This study explores provider preferences regarding anal cancer screening indications, initiation age, tools, and referral threshold to high resolution anoscopy (HRA).

Methods

International Anal Neoplasia Society affiliates were invited to complete an online survey. Options for initiation age and tools were delineated by sub-groups. HRA referral thresholds separately queried recommendations by patient immune status.

Results

One hundred forty respondents participated. Although consensus was lacking with regard to specific screening initiation age, more respondents recommended younger initiation ages for men who have sex with men (MSM) living with HIV (LWH) compared with MSM not LWH (p < 0.01). “No age threshold” ranged 44-55% among sub-groups with lower genital tract disease. Cytology and digital anorectal exam (DARE) were the most frequently selected tools for all sub-groups (ranges 77-90% and 74-86%, respectively). HRA was recommended significantly more frequently for MSM LWH (58%) and patients with vulvar cancer (52%) compared to others (p < 0.01). “Any [test] abnormality” was more often selected as indication for HRA for immunocompromised (56%) and immunocompetent (46%) patients than a specific cytology test result (29%, 36% respectively).

Conclusion

Cytology and DARE were preferred screening tools; screening initiation age and HRA referral threshold showed less consensus. Evidence-based guidelines are needed and may lead to more consistent screening practices.

Anal human papilloma viral infection and squamous cell carcinoma: Need objective biomarkers for risk assessment and surveillance guidelines

High grade anal intraepithelial neoplasia due to human papilloma viral (HPV) infections is a precursor lesion for squamous cell carcinoma especially in high risk populations. Frequent examination and anal biopsies remain unpopular with patients; moreover they are also risk factors for chronic pain, scarring and sphincter injury. There is lack of uniform, surveillance methods and guidelines for anal HPV specifically the intervals between exam and biopsies. The aim of this editorial is to discuss the intervals for surveillance exam and biopsy, based on specific HPV related biomarkers? Currently there are no published randomized controlled trials documenting the effectiveness of anal screening and surveillance programs to reduce the incidence, morbidity and mortality of anal cancers. In contrast, the currently approved screening and surveillance methods available for HPV related cervical cancer includes cytology, HPV DNA test, P16 or combined P16/Ki-67 index and HPV E/6 and E/7 mRNA test. There are very few studies performed to determine the efficacy of these tests in HPV related anal pre-cancerous lesions. The relevance of these biomarkers is discussed in this editorial. Longitudinal prospective research is needed to confirm the effectiveness of these molecular biomarkers that include high risk HPV serotyping, P16 immuno-histiochemistry and E6/E7 mRNA profiling on biopsies to elucidate and establish surveillance guidelines.

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.

Genome-wide host methylation profiling of anal and cervical carcinoma

HPV infection results in changes in host gene methylation which, in turn, are thought to contribute to the neoplastic progression of HPV-associated cancers. The objective of this study was to identify joint and disease-specific genome-wide methylation changes in anal and cervical cancer as well as changes in high-grade pre-neoplastic lesions. Formalin-fixed paraffin-embedded (FFPE) anal tissues (n = 143; 99% HPV+) and fresh frozen cervical tissues (n = 28; 100% HPV+) underwent microdissection, DNA extraction, HPV genotyping, bisulfite modification, DNA restoration (FFPE) and analysis by the Illumina HumanMethylation450 Array. Differentially methylated regions (DMR; t test q<0.01, 3 consecutive significant CpG probes and mean Δβ methylation value>0.3) were compared between normal and cancer specimens in partial least squares (PLS) models and then used to classify anal or cervical intraepithelial neoplasia-3 (AIN3/CIN3). In AC, an 84-gene PLS signature (355 significant probes) differentiated normal anal mucosa (NM; n = 9) from AC (n = 121) while a 36-gene PLS signature (173 significant probes) differentiated normal cervical epithelium (n = 10) from CC (n = 9). The CC progression signature was validated using three independent publicly available datasets (n = 424 cases). The AC and CC progression PLS signatures were interchangeable in segregating normal, AIN3/CIN3 and AC and CC and were found to include 17 common overlapping hypermethylated genes. Moreover, these signatures segregated AIN3/CIN3 lesions similarly into cancer-like and normal-like categories. Distinct methylation changes occur across the genome during the progression of AC and CC with overall similar profiles and add to the evidence suggesting that HPV-driven oncogenesis may result in similar non-random methylomic events. Our findings may lead to identification of potential epigenetic drivers of HPV-associated cancers and also, of potential markers to identify higher risk pre-cancerous lesions.

Gaps and Opportunities to Improve Prevention of Human Papillomavirus-Related Cancers

Human papillomavirus (HPV) infections cause more than 35,900 cancers annually in the United States. Although cervical cancer is the most prevalent HPV-related malignancy in women, the virus is also responsible for a significant percentage of anal, vaginal, and vulvar cancers. A comprehensive approach to mitigating cervical cancer includes HPV vaccination (primary prevention), screening and treatment of precancerous lesions (secondary prevention), and diagnosis and treatment of invasive cancer (tertiary prevention). Although a successful strategy, there are opportunities to innovate and increase access that can also be adapted to address the unique clinical care gaps that exist with the other anogenital cancers. The Society for Women's Health Research held a series of interdisciplinary meetings and events, during which expert researchers, clinicians, patient advocates, and health care policy leaders evaluated the current landscape of HPV-related cancers and their effects on women's health. This report summarizes the discussions of this working group and areas it identified in which to address gaps in primary and secondary prevention approaches to improve access and health outcomes for women with HPV-related anogenital cancers.

Prevalence of high-risk human papillomavirus DNA and mRNA and its association with abnormal anal cytology in the Czech male anal cancer screening cohort

BACKGROUND

Anal cancer (AC) screening is justified in high-risk populations, particularly HIV-positive men having sex with men (MSM). HR-HPV testing could improve the efficiency of cytologically based screening of AC, as in the screening of biologically analogical cervical cancer. The specificity of HR-HPV testing is influenced by the prevalence of HR-HPV infection in the screened population. Reported anal HR-HPV DNA prevalence in MSM is high, but HR-HPV mRNA reflects rather long-term infections and is more specific for high-grade lesions. However, no data were published about HR-HPV DNA and mRNA prevalence in the Czech AC screening population.

METHOD

Results of liquid-based anal cytology of 203 predominantly HIV-positive MSM from the Czech AC screening cohort were correlated with results of DNA and E6/E7 mRNA testing of 14 HR-HPV types, and HPV16 genotyping. Eighty-one MSM underwent a standard anoscopy.

RESULTS

A total of 109 (53.7%) samples had abnormal cytology, with 12 (5.9%) ASC-H/HSIL, 67 (33.0%) samples cytologically negative, and 27 (13.3%) unsatisfactory. HR-HPV DNA was detected in 134 (66.0%) and HR-HPV RNA in 72 (35.5%) anal smears. HR-HPV mRNA and HPV16 mRNA positivity were associated with abnormal cytology (p = .0037, p = .0021). No significant association was found between HR-HPV DNA or HPV16 DNA positivity and abnormal cytology. No high-grade lesions were revealed by anoscopy.

CONCLUSION

Prevalence of anal HR-HPV DNA among Czech MSM is high, however, the prevalence of HR-HPV mRNA is half and associated with abnormal cytology. Our results indicate an increased efficiency of cytological screening when combined with HR-HPV mRNA testing.

Human Immunodeficiency Virus Infection Promotes Human Papillomavirus-Mediated Anal Squamous Carcinogenesis: An Immunologic and Pathobiologic Review

BACKGROUND

Anal squamous cell carcinoma (SCC) is a rare gastrointestinal malignancy with rising incidence, both in the United States and internationally. The primary risk factor for anal SCC is human papillomavirus (HPV) infection. However, there is a growing burden of disease in patients with human immunodeficiency virus (HIV) and HPV coinfection, with the incidence of anal SCC significantly increasing in this population. This is particularly true in HIV-infected men. The epidemiologic correlation between HIV-HPV coinfection and anal SCC is established; however, the immunologic mechanisms underlying this relationship are not well understood.

SUMMARY

HIV-related immunosuppression due to low circulating CD4+ T cells is one component of increased risk, but other mechanisms, such as the effect of HIV on CD8+ T lymphocyte tumor infiltration and the PD-1/PD-L1 axis in antitumor and antiviral response, is emerging as significant contributors. The goal of this article is to review existing research on HIV-HPV coinfected anal SCC and precancerous lesions, propose explanations for the detrimental synergy of HIV and HPV on the pathogenesis and immunologic response to HPV-associated cancers, and discuss implications for future treatments and immunotherapies in HIV-positive patients with HPV-mediated anal SCC. Key Messages: The incidence of anal squamous cell carcinoma is increased in human immunodeficiency virus (HIV)-infected patients, even in patients on highly active antiretroviral therapy. Locoregional HIV infection may enhance human papillomavirus oncogenicity. Chronic inflammation due to HIV infection may contribute to CD8+ T lymphocyte exhaustion by upregulating PD-1 expression, thereby blunting cytotoxic antitumor response.

Human papillomavirus 16 L1 gene methylation as a potential biomarker for predicting anal intraepithelial neoplasia in men who have sex with men (MSM)

The human papillomavirus (HPV) 16 early promoter and L1 gene methylation were quantitatively measured using pyrosequencing assay in anal cells collected from men who have sex with men (MSM) to determine potential biomarkers for HPV-related anal cancer. The methylation patterns of HPV16 genes, including the early promoter (CpG 31, 37, 43, 52, and 58) and L1 genes (CpG 5600, 5606, 5609, 5615, 7136, and 7145), were analyzed in 178 anal samples. The samples were diagnosed as normal, anal intraepithelial neoplasia (AIN) 1, AIN2, and AIN3. Low methylation levels of the early promoter (< 10%) and L1 genes (< 20%) were found in all detected normal anal cells. In comparison, medium to high methylation (≥ 20–60%) in the early promoter was found in 1.5% (1/67) and 5% (2/40) of AIN1 and AIN2-3 samples, respectively. Interestingly, slightly increased L1 gene methylation levels (≥ 20–60%), especially at the HPV16 5’L1 regions CpGs 5600 and 5609, were demonstrated in AIN2-3 specimen. Moreover, a negative correlation between high HPV16 L1 gene methylation at CpGs 5600, 5609, 5615, and 7145 and a percentual CD4 count was found in AIN3 HIV positive cases. When comparing the methylation status of AIN2-3 to that of normal/AIN1 lesions, the results indicated the potential of using HPV16 L1 gene methylation as a biomarker for HPV-related cancer screening.