Screening, Surveillance, and Treatment of Anal Intraepithelial Neoplasia

Anal cancer prevention: A field in need of scientific Advancement

Despite the availability of several human papillomavirus (HPV) vaccines, the incidence of HPV-associated anal cancer is growing at a rate of 2.2% each year. As shown in results from the recent Phase III ANCHOR study, the treatment of high-grade anal lesions in people living with HIV (PLWH) can significantly reduce rates of anal cancer development compared to active surveillance alone. As a result, screening programs to identify and treat patients with anal precancers are recommended by recent guidelines. Intense resources are needed to perform screening tests and follow-up abnormal results. The lack of effective and well-tolerated therapies, the lack of understanding regarding therapeutic targets, the paucity of preclinical models to test therapies, and the lack of biomarkers to determine which patients will develop cancer or respond to therapies are the issues that need to be addressed. We provide an overview of cutting-edge research and propose additional research that is needed to help move the field of anal cancer prevention forward. This review highlights the most significant current areas of research, as defined by the authors, and is by no means comprehensive of all anal dysplasia/cancer research.

Topical Protease Inhibitor Increases Tumor-Free and Overall Survival in CD4-Depleted Mouse Model of Anal Cancer

Patients with immunodeficiencies and older age are at an increased risk of anal cancer. Transgenic K14E6/E7 mice with established high-grade anal dysplasia were treated topically at the anus with the protease inhibitor saquinavir (SQV) in the setting of CD4+ T-cell depletion to mimic immunodeficiency. To ensure tumor development, specific groups were treated with a topical carcinogen (7,12-Dimethylbenz[a]anthracene (DMBA)). The treatment groups included the vehicle (control), DMBA only, topical SQV, and topical SQV with DMBA, as well as the same four groups with CD4 depletion. The mice were monitored weekly for tumor development. Upon reaching 20 weeks of treatment, the mice were sacrificed, and their anal tissue was harvested for histological analysis. None of the mice in the SQV or control groups developed overt anal tumors, except three mice that were CD4-depleted. The CD4-depleted mice treated with DMBA had significantly increased tumor-free survival and overall survival as well as decreased tumor-volume growth over time when treated with SQV. These data suggest that topical SQV, in the setting of CD4 depletion and high-grade anal dysplasia, can increase tumor-free and overall survival; thus, it may represent a viable topical therapy to decrease the risk of progression of anal dysplasia to anal cancer.

A comprehensive review of anal cancer-with a special focus on anal cytology

The diagnosis of anal cancer is relatively uncommon, but its incidence has been steadily increasing in high-risk populations. In the 2001 Bethesda System for Reporting Cervical Cytology, anal cytology was introduced as a component. Since then, it has been recognized as a potential tool for screening anal cancer, often in conjunction with high-resolution anoscopy. There are notable similarities between anal cancer and cervical cancer, including the causative role of human papillomavirus. However, there are also significant differences, particularly in terms of disease prevalence. Anal cytology may be used as a primary screening test, and in the event of abnormalities, patients are subsequently directed for high-resolution anoscopy. However, the best approach for anal cancer screening is yet to be determined and uniformly implemented. This comprehensive review article provides an in-depth analysis of the epidemiology and incidence of anal precursor and malignant lesions. It explores the various methods of sample procurement, preparation, interpretation (including sensitivity and specificity), and reporting terminology in anal cytology. The article also addresses the significance of concurrent high-risk human papillomavirus screening in anal cytology and its role in screening programs. Furthermore, it discusses the follow-up, prevention, and subsequent management strategies for anal cancers. By synthesizing current knowledge in these areas, this review aims to provide a comprehensive understanding of anal cytology and its implications in the early detection, prevention, and management of anal neoplasia and cancer.

Case Report: Resolution of high grade anal squamous intraepithelial lesion with antibiotics proposes a new role for syphilitic infection in potentiation of HPV-associated ASCC

Introduction

Human Papillomavirus (HPV) is the primary risk factor for the development of anal intraepithelial neoplasia (AIN) and is a leading risk factor for anogenital squamous cell carcinoma (ASCC). Despite common shared risk factors for both HPV and syphilis, co-infection is not well documented, and the role of syphilitic infection in HPV-associated AIN and ASCC potentiation is not defined.

Case description/methods

A 72-year-old single male presented with complaints of mild rectal pain and intermittent rectal bleeding. A flexible sigmoidoscopy was performed, and a firm 4.5cm x 3cm perianal mass was detected and superficially biopsied. Pathology findings demonstrated evidence of a high grade squamous intraepithelial lesion (HGSIL, AIN II/III/AIS) with viral cytopathic effect, consistent with HPV infection. Much of the biopsied lesion showed acanthotic squamous mucosa with intraepithelial neutrophils and abundant submucosal plasma cells, suggesting possible syphilitic involvement. Subsequent immunohistochemical staining for p16 as a surrogate marker for HPV was positive, as was an immunohistochemical stain for spirochetes, supportive of co-infection with Treponema pallidum pallidum (T. pallidum), the causative agent in venereal syphilis. The patient was referred to an infectious disease specialist for syphilitic infection and was treated with penicillin with surprisingly complete resolution of the lesion. EUAs were performed 2- and 3-months following treatment without lesion recurrence. However, one year following diagnosis, a flexible sigmoidoscopy revealed a 5 mm recurrent HPV-related low-grade AIN 1 lesion at the dentate line.

Discussion

Resolution of the lesion by antibiotic treatment for syphilitic infection suggested that co-infection by T. pallidum may potentiate HPV-associated squamous cell carcinoma based on histological findings. Findings from this case, as well as a review of bacterial involvement and potentiation in various cancers, are reviewed here. Such findings offer new insight regarding the role of STI-associated bacteria and HPV co-infection in the establishment of AIN and may additionally propose new treatment modalities for ASCC.

Accuracy of narrow-band imaging in predicting the histology of anal intraepithelial lesions

BACKGROUND AND AIM

Anal intraepithelial neoplasia (AIN) is the precursor of anal squamous carcinoma, frequently underappreciated by most gastroenterologists. Purpose of the study is to assess the diagnostic accuracy of narrow-band imaging (NBI) in predicting the histology of anal lesions, considering a new NBI classification.

METHODS

This is a retrospective analysis of consecutive patients with suspected anal squamous intraepithelial lesions (SILs) and superficially invasive squamous cell carcinoma (SISCCA) who underwent anorectal-sigmoidoscopy. Three expert endoscopists reviewed all the images collected during colonoscopies in white light and NBI in order to generate a practical classification of three main different NBI patterns.

RESULTS

After the modified Delphi process, the final NBI classification, mainly based on intrapapillary capillary loops (IPCL) changes included three different NBI pattern. NBI pattern I: elongation of IPCL toward epithelial surface; NBI pattern 2: thickened and tortuous IPCL; NBI pattern 3: mosaic-like disposition of IPCL. We found that NBI pattern positively correlated to the histologic type of the lesions and tumor grade (Spearman's rho = 0.9671, P = 0.0000). Among 58 anal lesions included, 41/41 (100%) LSILs have been classified as NBI pattern I, 10/11 (90.91%) HSILs as NBI pattern II, 1/11 HSIL as NBI pattern I, 4/4 SISCCA as NBI pattern III and 2/2 invasive cancer as NBI pattern III. Diagnostic accuracy of NBI pattern II or III in predicting histology differentiating HSIL or SISCCA/IC versus LSIL showed a sensitivity of 100%, (95% CI: 92.3-100%) and a specificity of 94.1% (95% CI: 83.8-98.3%).

CONCLUSION

The accuracy of this new NBI score system in predicting the histology of anal lesions showed encouraging data in term of sensitivity and specificity in differentiating HSIL or SISCCA/IC versus LSIL, but the clinical usefulness and application of these findings should be evaluated in a prospective larger study.

Anal Intraepithelial Neoplasia: Precursor of Anal Squamous Cell Carcinoma

Anal squamous cell carcinoma (SCC) is rare, but it has been commonly detected as an invasive cancer. The standard treatment for anal SCC was surgical resection. However, recent medical advances have enabled the standard treatment to be chemoradiotherapy. Anal intraepithelial neoplasia (AIN) is a premalignant lesion of SCC. The screening test for AIN and human papilloma virus vaccine are important for the following high-risk patients: patients positive for human immunodeficiency virus and men who have sexual intercourse with men. Although cytology can be easily applied for a screening test, the false-negative rate for AIN is high. Instead, high-resolution anoscopy (HRA) has been gaining attention as a promising screening method for high-risk patients. Investigations comparing characteristic findings of HRA with the histology of AIN have demonstrated that HRA is a highly specific test for AIN. Magnifying or image-enhanced endoscopies are also routinely used for colonoscopy, as they allow detailed observations at higher magnifications than those of HRA. Hence, these endoscopic modalities can be applied for assessing AIN. Ablation therapies or topical medications are available as the local treatment for AIN. Although endoscopic submucosal dissection is considered to be feasible to remove AIN, it has a technical difficulty to approach endoscopically invisible areas. Hence, this technique may be useful to resect AIN localized in the endoscopically visible areas, when the localization is confirmed via targeted biopsy.

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.

The other side of screening: predictors of treatment and follow-up for anal precancers in a large health system

BACKGROUND

Anal cancer disproportionately affects people with HIV (PWH). High-grade squamous intraepithelial lesions (HSIL) are cancer precursors and treating them might prevent anal cancer. Data on adherence to HSIL treatment and surveillance is limited but needed to identify deficiencies of screening strategies.

METHODS

We collected data on high-resolution anoscopy (HRA) attendance and outcomes from 2009 to 2019 in a large urban anal cancer-screening program. Patients with an initial HSIL diagnosis were followed for return for HSIL electrocautery ablation within 6 months of index HSIL diagnosis, and follow-up HRA within 18 months of index HSIL diagnosis. We also evaluated predictors of these outcomes in univariable and multivariable analyses.

RESULTS

One thousand one hundred and seventy-nine unique patients with an anal HSIL diagnosis were identified and 684 (58%) returned for electrocautery ablation. Of those treated, only 174 (25%) and only 9% of untreated HSIL patients (47 of 495) underwent surveillance HRA within 18 months of index HSIL diagnosis. In multivariable analyses, black patients and PWH regardless of virologic control were less likely to undergo HSIL ablation within 6 months of HSIL diagnosis whereas patients with commercial insurance were more likely to be treated within 6 months of diagnosis. Among treated HSIL patients, PWH with viremia had a lower likelihood of engaging in post-treatment surveillance within 18 months of HSIL diagnosis.

DISCUSSION

Even in large specialized anal cancer screening programs adherence to HSIL treatment and surveillance is low. Psychosocial and economic determinants of health may impact retention in care. Addressing both personal and structural barriers to patient engagement may improve the effectiveness of anal cancer screening.

Retrospective 15-Year Review of Anal Cytology Screening in Women at Mayo Clinic Rochester, Minnesota

OBJECTIVES

Anal cytology is a modality for anal cancer screening in high-risk women. In this retrospective study, we review risk factors associated with abnormal anal cytology and unsatisfactory anal cytology rates, and correlate findings of cytology with histological results.

METHODS

A retrospective cohort study of anal cytology screening in women at Mayo Clinic in Rochester, Minnesota from 2002 to 2018 was conducted.

RESULTS

Three hundred fifty-seven women had a total of 592 anal cytologies performed. Three hundred seventeen women had screening anal cytology, whereas 40 women had anal cytology for surveillance given a history of anal intraepithelial neoplasia (AIN) or anal cancer. An unsatisfactory anal cytology result was found in 14.7%. Risk factors, type of follow-up, and correlation with histologic specimens were also reviewed. Histologic finding of AIN 2/3 correlated with abnormal anal cytology 84% of the time in this cohort.

CONCLUSIONS

High-risk women should be screened on a periodic basis for anal cancer. Anal cytology is one possible modality that can be used. Further insight into AIN progression, regression, recurrence, and outcome after treatment will help direct future screening recommendations.

Quality of life in women with HPV and accurary of direct visual anal inspection with acetic acid and lugol compared to high-resolution anoscopy to diagnose intraepithelial anal lesion

Abstract Objectives: to describe life quality of women with HPV and analyze the accuracy of anal visual inspection with acetic acid and lugol compared to high-resolution anoscopy in the detection of anal intraepithelial lesions. Methods: diagnostic evaluation study conducted with adult solid-organ transplant recipients and/or diagnosed with HIV and/or with a history of anogenital neoplasia, attended at the High Resolution Anoscopy outpatient clinic between April and December 2018. To calculate the accuracy parameters, 87 women participated: 44 with lesions and 43 without them. The 44 women with lesions were also subjected to a descriptive study to assess their life quality using the SF-36 questionnaire. Results: it was observed that almost half of the women in the study practiced vaginal, anal and oral intercourse without condom. History of HPV infection and anogenital neoplasia were the most prevailing with percentages of 81% and 72.7%, respectively. In five out of the eight domains of SF-36 they did not perform well in regard to life quality. Visual inspection with acetic acid and lugol presented sensitivity of 22.7% and specificity of 100%. Conclusion: unsatisfactory life quality was evidenced. Direct visual inspection with acetic acid and lugol should not be used in trials to spot intraepithelial HPV lesions, for it presents low sensitivity.

A 12-year retrospective evaluation of anal pre-cancerous lesions and cancer in people living with HIV-1 infection in the Southeastern U.S

Background

Anal cancer is rare in the general population in both genders in the US, but an increased incidence of anal cáncer (AC) has been reported among people living with HIV-1 infection (PLWH) and little is known among the population in South US.

Methods

In a retrospective study design, electronic health records from 2006 to 2018 were reviewed in a HIV clinical cohort at the University of Alabama at Birmingham. Associations of demographic, sociodemographic, and HIV-clinical indicators were examined in univariate analyses between high-grade squamous intraepithelial lesions (HSIL) and AC cases and condition-free individuals. Factors for anal/rectal cytology screening tests among PLWH were also assessed over time. Ages at onset of anal cancer were compared with the general US population reported by the National Surveillance, Epidemiology, and End Results Program.

Results

A total of 79 anal HSIL (96% men) and 43 cancer (100% men) patients were observed along with 4367 HSIL/cancer-free patients (75.9% men). HSIL (P < 0.0001) and AC (0.0001 < P < 0.01) were associated with being men who have sex with men (MSM). An incidence of 258 per 100,000 person-year was observed among this clinical cohort of PLWH. PLWH who were 45–54 years appeared to be at highest risk of AC (58.1%), as compared to those 55–64 years in the general population. Overall, 79% of PLWH anal cancers were diagnosed among those under 55 years (vs 39.5% in general population) indicating early onset of AC. In total 29.1% of HSIL and 44.2% of AC patients had not received an anal/rectal cytology examination 1 year prior to diagnosis.

Conclusion

AC incidence among HIV-infected men was 161 times higher than general population with an earlier age of onset/diagnosis. Many patients with AC had missed screening opportunities that could potentially have captured neoplasia in pre-cancerous stages. AC-related screening guidelines need to be integrated into routine clinical care, especially among PLWH at highest risk such as MSM and those with lower CD4 counts.

Screening for intra-anal squamous intra-epithelial lesions in women with a history of human papillomavirus-related vulvar or perianal disease: results of a screening protocol

AIM

Women with a history of human papillomavirus (HPV)-related cervical, vaginal or vulvar high-grade squamous intra-epithelial lesions (HSILs) or cancer are at increased risk of developing anal squamous intra-epithelial lesions (SILs) or a squamous cell carcinoma of the anus (SCCA). Screening for intra-anal SILs with high-resolution anoscopy (HRA) in high-risk populations is a subject of debate. In this study we aimed to answer the following question: what is the prevalence of intra-anal (H)SIL in women with HPV-related vulvar and/or perianal disease using HRA for screening?

METHOD

A retrospective study was performed to evaluate the prevalence of intra-anal (H)SIL in women with a history of vulvar and/or perianal HSIL or (superficially invasive) squamous cell carcinoma (SCC). This study was performed between 2015 and 2018 following implementation of a protocol for intra-anal screening using HRA.

RESULTS

Twenty-seven patients, 10 with a history of (superficially invasive) SCC (four vulvar, five perianal, one multizonal) and 17 with HSIL as the worst diagnosis (two perianal, 15 multizonal) were screened for intra-anal lesions using HRA. No anal cancer was found at screening, 6 (22%) patients were diagnosed with intra-anal HSIL and 12 (44%) patients with intra-anal low-grade SIL.

CONCLUSIONS

We found a high prevalence of intra-anal HSIL in women previously diagnosed with vulvar and perianal HSIL. Given the clear link between HSIL and SCCA, screening for intra-anal lesions in women with HPV-related genital pathology seems warranted. Future studies should focus on the effect of HSIL treatment on the prevention of anal cancer.

Correlation of anal cytology with follow-up histology and Human Papillomavirus genotyping: A 10-year experience from an academic medical center

BACKGROUND

Anal cytology (AC) is accepted as a practical screening modality for anal cancer. However, studies suggest that AC and anal biopsy dysplasia correlation is less robust than in cervicovaginal specimens. The current study goals were to look at our institutional experience in a subset of ACs and correlate with surgical pathology (SP), as well as evaluate their Human Papillomavirus (HPV) status.

METHODS

377 ACs from 169 patients (151 males and 18 females) from 2008 to 2017 were included. HPV genotyping (n = 47) and SP within one year of AC (n = 58) were reviewed.

RESULTS

AC/SP was discrepant in 22 cases (37.9%), with a tendency towards AC underestimating the degree of dysplasia. Specifically, any abnormality on AC was 93.8% sensitive for detecting high-grade dysplasia (HGD). However, when requiring a high-grade AC diagnosis, the sensitivity decreases to 12.5%. "Other high-risk HPV" was the most common genotype (57.4%). When considered with all AC with a high-grade diagnosis, co-testing with HPV improved the sensitivity for HGD to 56.3%. Sensitivity improved further to 87.5% when only considering cases with both AC and HPV testing, and were high-risk HPV positive. Furthermore, following review and consensus diagnosis, 8 cases changed from "Discrepant" to "Agreed", reducing the discrepancy rate to 24.1%. Remaining discrepancies were explained by sampling error.

CONCLUSION

Given the enhanced sensitivity of AC and HPV testing together, and sampling error seen with AC leading to underestimating dysplasia, we recommend AC and HPV co-testing, as well as describing confounding factors in AC reports and obtaining consensus opinion in equivocal cases.

Exophytic condyloma: are they as benign as we think?

AIM

As the understanding of anal dysplasia continues to develop, controversy remains regarding treatment of these lesions. The purpose of this study was to evaluate lesion type (flat vs exophytic) and the association between morphology and dysplasia.

METHODS

This was a single-centre retrospective analysis of a prospectively collected pathological database of patients > 17 years old who underwent operative excision/biopsies for presumed anal condyloma or dysplasia from 2009 to 2018. The analysis includes comparisons between patient factors, phenotype and grade of dysplasia.

RESULTS

Sixty-nine patients had 423 lesions. The mean age of the study population was 48.2 years. 62.3% were men and 46.4% of patients were black. 47.8% of patients were human immunodeficiency virus (HIV) positive and 39.1% were men who have sex with men (MSM). There were 176 (41.6%) flat lesions and 234 (55.3%) exophytic lesions. Exophytic lesions were 2.5-fold more likely to be associated with a higher grade of dysplasia than flat lesions (OR 2.63, 95% CI 1.09-6.32). Neither lesion type nor dysplasia severity was associated with human papillomavirus, lesion location or patient characteristics, including race, MSM or HIV status.

DISCUSSION

Exophytic lesions were more than twice as likely to have advanced dysplasia compared with flat lesions. A clearer understanding of the association between gross lesion appearance and dysplasia will allow more appropriate counselling of patients and the development of better screening and treatment guidelines for anal condylomata and dysplasia.

Association of antiretroviral therapy with anal high-risk human papillomavirus, anal intraepithelial neoplasia, and anal cancer in people living with HIV: a systematic review and meta-analysis

BACKGROUND

The effect of antiretroviral therapy (ART) on the natural history of anal high-risk HPV and anal lesion progression is not well established. We reviewed the association of ART and other HIV-related factors on anal HPV infection, anal intraepithelial neoplasia (AIN), and anal cancer among people living with HIV.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE and EMBASE for studies published between Jan 1, 1996, and Oct 30, 2019, that reported the association of HIV-related exposures (ART or highly active ART [HAART], HIV-RNA plasma viral load [PVL], and nadir or current CD4 cell count) with outcomes of anal high-risk HPV prevalence, incidence, and persistence; prevalence, incidence, progression, or regression of anal histological and cytological abnormalities; and anal cancer incidence. Effect estimates were extracted whenever available; otherwise, they were calculated from raw data. We assessed the risk of bias of included studies using the Newcastle-Ottawa scale, and random-effects meta-analyses were done to examine heterogeneity using the I² statistic. This study is registered on the PROSPERO database, CRD42018007271.

FINDINGS

We identified 6777 studies, of which 5377 were excluded before full-text review. 122 studies providing estimates for 130 distinct populations matched the inclusion criteria. The populations comprised 417 006 people living with HIV (women, men who have sex with men, and men who have sex with women). 41 (32%) population estimates were not stratified by sex or sexual orientation. People living with HIV receiving ART had 35% lower high-risk HPV prevalence than ART-naive people (crude odds ratio [OR] 0·65, 95% CI 0·54-0·79; I² 12·1%, p=0·31) in 18 studies, and prolonged ART use was associated with a 10% reduction per year in high-risk HPV prevalence in two studies (adjusted OR 0·90, 0·85-0·95; I² 0%, p=0·88). People living with HIV with undetectable PVL had lower HSIL-AIN2+ prevalence than those with detectable PVL (crude OR 0·84, 0·72-0·98; I² 0%, p=0·80) in 16 studies, particularly if sustained for more than 1 year (crude OR 0·62, 0·47-0·81; I² 0%, p=0·51). ART was not associated with anal cancer incidence when adjusted for years living with HIV in three studies (adjusted hazard ratio [HR] 1·11, 95% CI 0·68-1·80; I² 0%, p=0·57), but ART users with sustained undetectable HIV PVL had 44% lower risk of anal cancer than those without (adjusted HR 0·56, 0·44-0·70; I² 0%, p=0·94) and for each increase in nadir CD4 cell counts of 100 cells per μL, there was a 40% decrease in anal cancer incidence (crude HR 0·60, 0·46-0·78; I² 21·7%, p=0·26).

INTERPRETATION

Effective ART use and early initiation at high nadir CD4 counts might reduce anal high-risk HPV infection and anal cancer risk. Although most studies were cross-sectional in design and few adjusted for potential confounders, this analysis provides comprehensive estimates of the effect of ART and HIV-related factors on the natural history of anal HPV-related disease in people living with HIV.

FUNDING

EU Marie Skłodowska-Curie Actions programme.

A Cell-Based Renilla Luminescence Reporter Plasmid Assay for High-Throughput Screening to Identify Novel FDA-Approved Drug Inhibitors of HPV-16 Infection

Like cervical cancer, anal cancer is caused by human papillomavirus (HPV). HPV is the most common sexually transmitted agent and is found in the anal canal of almost all HIV-positive men who have sex with men (MSM). Rates of HPV anal cancer are disproportionately higher in this population. Although the nanovalent HPV vaccine is efficacious in protecting against oncogenic HPV types, a substantial proportion of MSM remains unvaccinated and anal HPV infection continues to be an important public health burden. Therefore, it is important to identify strategies to prevent HPV infection. We report on two promising and interlinked strategies: (1) the development of a cell-based Renilla luminescence reporter assay using HPV-16 pseudovirions that encapsidate SV40-driven Renilla luminescence reporter expression plasmid and (2) use of this assay for high-throughput screening (HTS) of FDA- and internationally approved drugs to identify those that could be repurposed to prevent HPV infection. We conducted a screen of 1906 drugs. The assay was valid with a Z' of 0.67 ± 0.04, percent coefficient of variance of 10.0, and signal-to-background noise window of 424.0 ± 8.0. Five drugs were chosen for further analyses based on selection parameters of ≥77.0% infection of HPV-16 pseudovirion-driven Renilla expression with <20.0% cytotoxicity. Of these, the antifungal pentamidine and a gamma-amino butyric acid receptor agonist securinine exhibited ≥90.0% infection with <10.0% cytotoxicity. This luminescent cell-based reporter expression plasmid assay for HTS is a valid method to identify FDA- and internationally approved drugs with the potential to be repurposed into prevention modalities for HPV infection.

Safety and immunogenicity of VGX-3100 formulations in a healthy young adult population

HPV remains the most common sexually transmitted disease worldwide, despite improvements in awareness, screening, prophylactic vaccination uptake, and surgical treatment. VGX-3100 is an immunotherapy that uses electroporation to introduce DNA encoding for modified HPV-16 and HPV-18, E6-and E7 proteins into myocytes to stimulate an effector T cell response. We now report immunogenicity and safety of VGX-3100 for a refrigeration-stable formulation, which improves patient-care setting usability.

This multi-arm, double-blinded, randomized trial enrolled 235 healthy men and women to receive either a refrigerated (RF) or frozen formulation (FF) of VGX-3100. Three doses were administered intramuscularly with electroporation at 0, 4, and 12 weeks. Non-inferiority of RF to FF was assessed by comparing the proportion of subjects who achieved a ≥2-fold increase from baseline to Week 14 in Spot Forming Units/10⁶ PMBCs using an interferon-γ enzyme-linked immunospot assay.

There were no related SAEs. Injection site reactions were the most common adverse event (54%, RF; 66%, FF) the majority of which resolved within a few minutes following administration. The primary endpoint was met with 89.9% of RF recipients and 97.2% of FF recipients reaching a ≥2-fold rise in SFU/10⁶ PBMC, 2 weeks following the last dose; RF was statistically non-inferior to FF (p = .022).

A systemic, immunologic approach has the potential to fill a critical gap in the ability to treat men and women with high grade HPV diseases. These safety and immunogenicity data are supportive of the continued development of a refrigerated formulation of VGX-3100.

Screening for anal cancer precursors among patients living with HIV in the absence of national guidelines: practitioners' perspectives

PURPOSE

Immunocompromised populations including people living with HIV (PLWH) suffer disproportionate burden from anal cancer, a rare cancer caused by persistent infection of the anal canal with oncogenic strains of human papillomavirus. In the US, there are no nationally adopted screening guidelines for anal cancer. In the absence of such guidelines, this study explores healthcare practitioners' screening practices for early signs of anal cancer among PLWH.

METHODS

Between November 2017 and June 2018, the research team completed 25 interviews among a diverse sample of healthcare practitioners who provide care for PLWH.

RESULTS

Providers expressed frustration that screening and treatment guidelines for anal cancer were scant, and they varied in their screening practices. The majority of providers screened PLWH for anal dysplasia via the anal Pap smear; few providers were trained and had the medical equipment to conduct high-resolution anoscopy-guided biopsies, a more sensitive and specific screening method. Others screened through digital ano-rectal examinations (DARE) and both visually and with a DARE. Participants discussed how providers may be over-treating their patients who have high-grade anal intraepithelial neoplasia (AIN) and the role of biomarkers to determine whether the lesion is carcinogenic.

CONCLUSIONS

Practitioners who provide care for PLWH are proactive in screening to help prevent and control anal cancer, a rare and slow-growing disease. Continuing to regularly surveil high-risk populations, particularly PLWH previously diagnosed with high-grade lesions, is critical to prevent and control anal cancer.

Anal intraepithelial neoplasia: diagnosis, screening, and treatment

Anal intraepithelial neoplasia (AIN) is a premalignant lesion for anal cancer. It is more commonly found in high-risk patients (e.g., human papilloma virus (HPV)/human immunodeficiency virus infections, post-organ transplantation patients, and men who have sex with men) and development is driven by HPV infection. The incidence of AIN is difficult to estimate, but is heavily skewed by preexisting conditions, particularly in high-risk populations. The diagnosis is made from cytology or biopsy during routine examinations, and can be performed at a primary care provider’s office. A pathologist can then review and classify cells, based on nucleus-to-cytoplasm ratios. The classification of low or high grade can better predict progression from AIN to anal cancer. There is little debate that AIN can develop into anal cancer, and the main rationale for treatment is to delay the progression. Significant controversy remains regarding screening, surveillance, and treatment for AIN. Management options are separated into surveillance (watchful waiting) and interventional strategies. Emerging data suggest that close patient follow up with a combination of ablative and topical treatments may offer the greatest benefit. HPV vaccination offers a unique treatment prior to HPV infection and the subsequent development of AIN, but its use after the development of AIN is limited. Ablative treatment includes excision, fulguration, and laser therapy.

HPV Vaccine in Adolescents

Human papillomavirus (HPV), the most common sexually transmitted viral infection worldwide, is the causative agent for cervical cancer and attributed to anogenital cancers as well as oropharyngeal cancer. Three effective, safe, prophylactic HPV vaccines have been licensed, and studies have demonstrated decreases in HPV prevalence and HPV-related disease endpoints without evidence of waning protection to date. In the United States, only the 9-valent vaccine, which covers 90% of the cancers attributed to HPV in US registries, is available. Because higher titers are found at younger ages, two rather than three doses are needed if the first dose is given prior to age 15 years. HPV vaccination rates in the US lag compared to tetanus-diptheria-acellular pertussis and meningococcal conjugate vaccines. Current efforts are aimed at improving vaccination rates through delivering strong and consistent clinician recommendations at the same time as discussing other adolescent vaccines and preventing missed opportunities for vaccination. [Pediatr Ann. 2019;48(2):e71-e77.].

An overview of anal intraepithelial neoplasia

Anal intraepithelial neoplasia (AIN) and anal squamous cell carcinoma (ASCC) are on the rise in the United States, especially among men who have sex with men, HIV-positive or other immunocompromised patients, and women with a history of cervical, vaginal, or vulvar cancer. Strong evidence supports the human papillomavirus as the causative factor in anal dysplasia; reducing the risk of HPV infection can reduce rates of ASCC. High-risk patients should be screened for AIN, but no universal screening guidelines exist, and more studies are needed to develop a national protocol for screening and management of patients with AIN.

Basic Science, Epidemiology, and Screening for Anal Intraepithelial Neoplasia and Its Relationship to Anal Squamous Cell Cancer

Despite the progress made in the reduction of squamous cell carcinoma of the cervix, the incidence of anal squamous cell carcinoma (ASCC) has been increasing since 1992. While it remains an uncommon disease, the prevalence is climbing steadily. Among human immunodeficiency virus (HIV)-infected adults, especially men who have sex with men, ASCC is one of the more common non-AIDS-defining malignancies. The precursor lesion, anal intraepithelial neoplasia (AIN), is prevalent in the HIV-infected population. More than 90% of ASCCs are related to human papilloma virus (HPV), oncogenic types (HPV 16, 18). While the biology of HPV-related intraepithelial neoplasia is consistent in the anogenital area, the natural history of AIN is poorly understood and is not identical to cervical intraepithelial neoplasia (CIN). CIN is also considered an AIDS-defining malignancy, and the methods for screening and prevention of AIN are derived from the CIN literature. This article will discuss the epidemiology of ASCC and its association with HPV and the life cycle of the HPV, and the molecular changes that lead to clearance, productive infection, latency, and persistence. The immunology of HPV infection will discuss natural immunity, humoral and cellular immunity, and how the HPV virus evades and interferes with these mechanisms. We will also discuss high-risk factors for developing AIN in high-risk patient populations with relation to infections (HIV, HPV, and chlamydia infections), prolonged immunocompromised people, and sexual behavior and tobacco abuse. We will also discuss the pre- and post-HAART era and its effect on AINs and ASCC. Finally, we will discuss the importance of anal cytology and high-resolution anoscopy with and without biopsy in this high-risk population.

Anal Intraepithelial Neoplasia from a Pathologists Point of View

Anal squamous cell carcinoma is a relatively rare diagnosis, but its incidence has continued to rise. Anal squamous cell carcinoma and its precursor lesion, anal intraepithelial neoplasia (AIN), are human papillomavirus (HPV)-associated squamous neoplasias. High-risk HPV subtypes cause cellular proliferation in the anal transformation zone mucosa leading to similar dysplastic changes as seen in the cervix. Unified cytologic and histologic classification systems have emerged for all HPV-associated squamous lesions of the lower anogenital tract due to recent advancements in the understanding of these lesions. P16 immunohistochemical stain, a biomarker for HPV, is recommended in the diagnosis of HPV-associated lesions. The unity of terminology will aid in communication between pathologists and clinicians, ultimately leading to improved patient care.

Biomarker P16 predicts progression risk of anal low-grade squamous intraepithelial lesions

OBJECTIVES

The aim of this study was to determine whether biomarker P16 predicts progression risk for anal low-grade squamous intraepithelial lesions (LSILs).

DESIGN

A retrospective study.

METHODS

One hundred and nine HIV-infected and 18 HIV-uninfected patients with biopsy-proven anal LSIL at initial screening underwent surveillance high-resolution anoscopy and biopsy within 2 years of diagnosis. P16 immunohistochemistry was performed on index lesions and evaluated using a semi-quantitative scoring system. The association of predictors and lesional outcomes (progression, persistence or regression) was analysed using ordinal logistic regression models. A subset of p16-positive LSILs was tested for high-risk human papillomavirus (HR-HPV) DNA using real-time PCR.

RESULTS

Upon follow-up, 46 (36%) LSILs progressed to high-grade squamous intraepithelial lesion (HSIL), 50 (40%) persisted as LSIL and 31 (24%) regressed to benign mucosa (median 16 months, range 5-24 months). Age, sex, race, history of condylomata, CD4 T-cell count and HIV plasma viral load were similar regardless of clinical outcome. P16 immunoreactivity of index lesion was classified as block-positive (n = 36), focal-positive (n = 49) or negative (n = 42). Sixty-four percent of block-positive lesions progressed, as opposed to 35% of focal-positive and 14% of negative lesions (P < 0.001). HR-HPV DNA was detected in 90% of p16 block-positive lesions vs. 55% of focal-positive lesions. In unadjusted analyses, positive p16, HIV and former smoker status were significantly associated with lesional persistence and progression. P16 remained the only significant predictor in an adjusted model.

CONCLUSION

Biomarker p16 is the strongest predictor for anal LSIL-to-HSIL progression, outperforming other risk factors. To enhance the overall effectiveness of surveillance, we propose using p16 immunohistochemistry to help stratify patients at high vs. low risk of progression.

Clinical evaluation of anal intraepithelial neoplasia: are we missing the boat?

BACKGROUND

Anal intraepithelial neoplasia (AIN) is dysplasia in the epithelium of the anus and is a pre-malignant condition associated with a low rate of progression to invasive squamous cell carcinoma (SCC). The natural history of progression for AIN to anal SCC is poorly defined. This study aims to review our experience with AIN and investigate the natural history of progression.

METHODS

Data on all patients with AIN from January 2005 to December 2015 were retrospectively reviewed. Three separate databases were searched - Colorectal, Radiation Oncology and Infectious Diseases. All databases were cross-referred to obtain a complete but non-duplicated data set. Electronic charts were reviewed to obtain clinical information.

RESULTS

Twenty-eight patients were identified with AIN of various grades. There were 25 males, three females. Twenty of the male patients were human immunodeficiency virus (HIV) positive. Mean length of follow up was 56 months. Complete regression of AIN to normal was noted in 13 patients (46%). Four patients had persisting AIN III with no evidence of regression or malignant transformation. Nine patients with pre-existing AIN developed SCC (32%). Seven were positive for HIV infection (all males). Median time to progression was 36 months. None of the patients demonstrated clear linear pattern of progression of AIN to SCC.

CONCLUSION

High grade AIN may progress to anal SCC and surveillance is indicated. The exact natural history of progression for AIN is difficult to predict. There is no linear progression over time evident. HIV patients with AIN are at higher risk of developing SCC.

Endoscopic submucosal dissection (ESD) for anal high-grade intraepithelial neoplasia: a case report

Anal intraepithelial neoplasia (AIN) is a precursor of anal carcinoma. Conventional therapy is based on topical and local ablative approaches. However, the recurrence rates are very high, leading to repetitive treatment sessions and need for long-term surveillance. Endoscopic submucosal dissection (ESD) is an established treatment for malignant early neoplasias of the gastrointestinal tract, especially in the esophagus, stomach, and colorectum. Japanese centers have reported few cases of ESD for early anal carcinoma. We report a case of high-grade AIN diagnosed with magnifying narrow-band imaging and chromoendoscopy that was resected R0 with ESD en bloc.

Anal Cytology: Institutional Statistics, Correlation With Histology, and Development of Multidisciplinary Screening Program With Review of the Current Literature

Context.—

The incidence of anal cancer in the United States is on the rise in high-risk populations. The anal Papanicolaou test (APT) is advocated as a screening tool, in addition to digital rectal examination and high-resolution anoscopy.

Objective.—

To review our experience and the current literature to create, in cooperation with clinicians, a standardized screening and treatment algorithm given our large volume of APTs.

Data Sources.—

All APTs collected between January 2013 and June 2015 were reviewed and correlated with follow-up/concurrent biopsy diagnoses, and clinical and social history. In total, 1417 APTs were performed on 1185 patients and APT results were as follows: 17.4% (247 of 1417) unsatisfactory; 27.9% (395 of 1417) negative; 19.5% (276 of 1417) atypical squamous cells of undetermined significance (ASC-US); 24.1% (342 of 1417) low-grade squamous intraepithelial lesion (LSIL); 3.6% (51 of 1417) atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H); and 7.5% (106 of 1417) HSIL. In total 376 cases (26.5%) had concurrent/follow-up biopsy. Review of all unsatisfactory cases with squamous intraepithelial lesion (SIL) on biopsy showed LSIL in 19.2% (5 of 26). Anal Papanicolaou test with cytologic abnormality (ASC-US+) had an 83.8% (315 of 376) rate of biopsy-proven disease, and sensitivity was higher (92%) for high-grade anal intraepithelial neoplasia or worse (AIN2+). Overall detection of AIN2+ using ASC-US+ showed specificity of 26%, negative predictive value of 92%, and positive predictive value of 26%.

Conclusions.—

Anal cytology has a high abnormal rate (54.7%) and sensitivity but poor correlation with histologic grade. High unsatisfactory rate indicates need for improvement in sampling with 68.4% of cases having SIL on biopsy. Multidisciplinary effort led to improvements in sampling, cytologic interpretation, and development of a standardized management algorithm.

Human Papillomavirus in Kidney Transplant Recipients

Human papillomavirus (HPV) is a common infection in kidney transplant recipients. HPV causes cervical, anal, vulvar, vaginal, penile and head and neck cancers. Kidney transplant recipients have a disproportionate burden of disease given prolonged immunosuppression. Given the long pre-invasive state of precancer lesions such as cervical intraepithelial neoplasia (CIN) and anal intraepithelial neoplasia (AIN) most HPV-cancers are preventable with screening and targeted treatment of disease. Pre-transplant vaccination of age-eligible kidney transplant recipients is otherwise ideal.

Are Prophylactic Antibiotic Agents Indicated in Anorectal Surgery for Patients with Human Immunodeficiency Virus?

BACKGROUND

With increased survival among patients with human immunodeficiency virus (HIV), surgeons have been seeing more cases of anal dysplasia and cancer. There is, however, no data on the incidence of surgical site infections (SSIs) in HIV-positive patients undergoing elective anorectal procedures, nor on the administration of prophylactic antibiotic agents. We reviewed a HIV-positive population that has undergone elective anorectal biopsy of areas of dysplasia observed on office anoscopy to assess the need for antibiotic prophylaxis.

PATIENTS AND METHODS

A retrospective chart review was performed of all HIV-positive patients seen as outpatients in the Colorectal Surgery Division from 2007-2016. Demographics, dates of surgery and follow-up, antibiotic prophylaxis, and pre-operative CD4 count and HIV viral load were recorded for 229 patients. Post-operative examination notes were reviewed to determine the presence of SSIs. The proportion of patients who received prophylaxis was assessed and the SSI rate was calculated.

RESULTS

Surgical site infections occurred in 2 of 237 (0.8%) cases without antibiotic prophylaxis and in none of the 38 cases with prophylaxis. This infection rate was found to be lower than that of the general surgery population, with no statistical difference from hemorrhoidectomy patients without HIV. One SSI occurred in a 51-year-old male with a pre-operative CD4 count of 612 per microliter and viral load of zero. Another occurred in a 57-year-old female with an unknown CD4 count and viral load. A χ² analysis showed the incidence of SSIs in the groups with and without prophylaxis was not significantly different (p = 0.563).

CONCLUSION

Surgical site infection rates in HIV-positive patients undergoing biopsies for anal dysplasia were similar to patients without HIV undergoing similar minor anorectal procedures, and no difference was noted in the rate of SSI with the administration of prophylactic antibiotic agents. We do not recommend routine use of prophylactic antibiotic agents in this population.

Condyloma Acuminatum, Anal Intraepithelial Neoplasia, and Anal Cancer in the Setting of HIV: Do We Really Understand the Risk?

BACKGROUND

The gold standard for surveillance of patients with anal lesions is unclear.

OBJECTIVE

The aim of this study was to stratify patients for risk of progression of disease and to determine appropriate intervals for surveillance of patients with anal disease.

DESIGN

This was a retrospective chart review for patients treated for anal lesions between 2007 and 2014. Only patients with ≥1 year of follow-up from index evaluation, pathology, documented physical examination, and anoscopy findings were included for analysis.

SETTINGS

The study was conducted at an urban university hospital.

PATIENTS

HIV-positive patients with anal lesions treated with excision and fulguration were included.

MAIN OUTCOME MEASURES

Recurrence of anal lesions, progression of disease, and progression to cancer were measured.

RESULTS

Ninety-one patients met inclusion criteria. The mean age was 41.6 years, and mean follow-up was 38.6 months (range, 11.0-106.0 mo). On initial pathology, 8 patients (8.8%) had a diagnosis of condyloma acuminatum without dysplasia, 20 patients (22%) had anal intraepithelial neoplasia I, 32 (35.2%) had anal intraepithelial neoplasia II, and 31 (34.1%) had anal intraepithelial neoplasia III. Sixty-nine patients (75.8%) had repeat procedures. Seven (87.5%) of 8 patients with condyloma and 6 (30%) of 20 patients with anal intraepithelial neoplasia I progressed to high-grade lesions. Five (15.6%) of 32 patients progressed from anal intraepithelial neoplasia II to III, and 2 patients with anal intraepithelial neoplasia III (6.5%) developed squamous cell carcinoma (2.3% for the entire cohort).

LIMITATIONS

This was a single institution study. High-resolution anoscopy was not used.

CONCLUSIONS

All of the HIV-positive patients with condyloma or anal intraepithelial neoplasia, regardless of the presence of dysplasia, should be surveyed at equivalent 3-month time intervals, because their risk of progression of disease is high. Video Abstract at http://links.lww.com/DCR/A389.

Anal intraepithelial neoplasia: A review of diagnosis and management

Anal intraepithelial neoplasia (AIN) is a premalignant lesion of the anal mucosa that is a precursor to anal cancer. Although anal cancer is relatively uncommon, rates of this malignancy are steadily rising in the United States, and among certain high risk populations the incidence of anal cancer may exceed that of colon cancer. Risk factors for AIN and anal cancer consist of clinical factors and behaviors that are associated with the acquisition and persistence of human papilloma virus (HPV) infection. The strongest HPV-associated risk factors are HIV infection, receptive anal intercourse, and high risk sexual behavior. A history of HPV-mediated genital cancer, which suggests infection with an oncogenic HPV strain, is another risk factor for AIN/anal cancer. Because progression of AIN to anal cancer is known to occur in some individuals over several years, screening for AIN and early anal cancer, as well as treatment of advanced AIN lesions, is reasonable in certain high-risk populations. Although randomized controlled trials evaluating screening and treatment outcomes are lacking, experts support routine screening for AIN in high risk populations. Screening is performed using anal cytological exams, similar to those performed in cervical cancer screening programs, along with direct tissue evaluation and biopsy via high resolution anoscopy. AIN can be treated using topical therapies such as imiquimod, 5-flurouracil, and trichloroacetic acid, as well as ablative therapies such as electrocautery and laser therapy. Reductions in AIN and anal cancer rates have been shown in studies where high-risk populations were vaccinated against the oncogenic strains of HPV. Currently, the CDC recommends both high-risk and average-risk populations be vaccinated against HPV infection using the quadrivalent or nonavalent vaccines. It is important for clinicians to be familiar with AIN and the role of HPV vaccination, particularly in high risk populations.