Performance of Anal Cytology Compared With High-Resolution Anoscopy and Histology in Women With Lower Anogenital Tract Neoplasia

Anal intraepithelial neoplasia screening in women from the largest center for lower genital tract disease in China

This study aimed to provide comprehensive clinical screening data for anal intraepithelial neoplasia (AIN). This study included 312 patients who underwent high-resolution anoscopy (HRA) examinations between January 1, 2020 and April 15, 2024. Clinical data, including demographic information, clinical history, cytology/high-risk human papilloma virus (hrHPV) results, and HRA records, were analyzed. The median age of all patients was 42 years (interquartile range: 33-52 years). Approximately 26.3% reported a history of VIN2/3+, 13.5% had a history of VaIN2/3+, 29.8% had a history of CIN2/3+, 44.6% had persistent cervical HPV16 infection, and 12.5% had immune suppression. Among the 312 patients, 14.4% were diagnosed with AIN2/3, 25.0% with AIN1 and 60.6% were normal. Anal cytological abnormalities were found in 41.3% of all patients, with a significantly higher rate in AIN2/3 patients than in ≤AIN1, 71.1% versus 36.3%, p < 0.001. The hrHPV positivity rate was 89.7%, with HPV16 being the most prevalent. The complete agreement rate for HRA impressions was 79.5%. Multi-variable analysis revealed immune suppression (odds ratio [OR]: 3.47, 95% confidence interval [CI]: 1.42-8.5) and VIN2/3+ (OR: 2.82, 95% CI: 1.27-6.28) were independent risk factors for AIN2/3. Abnormal cytology results (OR: 3.3, 95% CI: 1.52-7.17) and anal HPV16 infection (OR: 3.2, 95% CI: 1.26-8.12) demonstrated similar ORs for AIN2/3. Early screening for AIN2/3+ is crucial in Chinese women with lower genital tract precancerous and cancerous lesions, particularly in those with VIN2/3+ and immune suppression.

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.

Evaluating the performance of anal cytology and high-risk HPV genotyping for detecting anal HSIL in a clinic-based sample of people living with and without HIV in Puerto Rico

BACKGROUND

Given the disproportionately elevated anal cancer risk in high-risk populations, it is important to assess the performance of commonly used anal cancer screening tools to improve the effectiveness of detection and treatment methods. This study evaluates 1) the concordance between anal cytology and histology results and 2) the performance of cytology and high-risk human papillomavirus (HR-HPV) genotyping as screening tools for detecting histologically confirmed anal high-grade squamous intraepithelial lesions (HSIL).

METHODS

Data from the Anal Neoplasia Clinic in Puerto Rico (2014-2021; n = 466) was used. The clinical performance of anal cytology and HR-HPV genotyping to detect HSIL was compared to the gold standard: high-resolution anoscopy-guided biopsy. Sensitivity, specificity, positive predictive value, negative predictive value, and κ coefficients were calculated.

RESULTS

A total of 66.95% of the patients were men, 74.0% were people living with HIV, 76.2% had anal HR-HPV infection, and 40.34% had histologically confirmed anal HSIL. The weighted κ statistic between the tests (cytology and histology) was 0.25 (p < .001). The sensitivity and specificity of cytology alone to detect anal HSIL were 84.3% (95% confidence interval [CI], 78.3%-89.1%) and 36.0% (95% CI, 30.3%-42.0%), respectively. Anal HR-HPV genotyping had higher sensitivity (92.2%; 95% CI, 87.4%-95.6%) and similar specificity (34.8%; 95% CI, 29.2%-40.7%) compared to cytology. The two tests combined (positive results following cytology or HR-HPV test) improved sensitivity to detect anal HSIL (97.9%; 95% CI, 94.8%-99.4%), but specificity was compromised (19.2%; 95% CI, 14.7%-24.4%).

CONCLUSION

Although HR-HPV genotyping improved the detection of anal HSIL, HR-HPV testing had lower specificity than anal cytology alone.

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.

Anal High-risk Human Papillomavirus Infection, Squamous Intraepithelial Lesions, and Anal Cancer in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Ulcerative colitis [UC] and Crohn's disease [CD] can be associated with severe comorbidities, namely opportunistic infections and malignancies. We present the first systematic review and meta-analysis evaluating the burden of anal human papillomavirus disease in patients with UC and CD.

METHODS

PubMed, Web of Science, and Scopus were searched until November 2022. Meta-analyses were performed using random effects models. The protocol was recorded at PROSPERO register with the number CRD42022356728.

RESULTS

Six studies, including 78 711 patients with UC with a total follow-up of 518 969 person-years, described the anal cancer incidence rate. For anal cancer incidence rate in CD, six studies were selected, including 56 845 patients with a total follow-up of 671 899 person-years. The incidence of anal cancer was 10.2 [95% CI 4.3 - 23.7] per 100 000 person-years in UC and 7.7 [3.5 - 17.1] per 100 000 person-years in CD. A subgroup analysis of anal cancer in perianal CD, including 7105 patients, was calculated with incidence of 19.6 [12.2 - 31.6] per 100 000 person-years [three studies included]. Few studies described prevalence of anal cytological abnormalities [four studies including 349 patients] or high-risk human papillomavirus [three studies including 210 patients], with high heterogeneity. Prevalence of cytological abnormalities or high-risk human papillomavirus was not associated with pharmacological immunosuppression in the studies included.

CONCLUSION

The incidence of anal cancer is higher in UC than in CD, with the exception of perianal CD. There are limited and heterogeneous data on anal high-risk human papillomavirus infection and squamous intraepithelial lesions prevalence in this population.

Anal Cancer in High-Risk Women: The Lost Tribe

In developed countries the incidence of anal squamous cell carcinoma (SCC) has been rising; especially in women over the age of 60 years who present with more advanced disease stage than men. Historically, anal SCC screening has focused on people living with Human Immunodeficiency Virus (HIV) (PLWH) who are considered to be at the highest risk of anal SCC, and its precancerous lesion, anal squamous intraepithelial lesion (SIL). Despite this, women with vulval high-grade squamous epithelial lesions (HSIL) and SCCs have been shown to be as affected by anal HSIL and SCC as some PLWH. Nevertheless, there are no guidelines for the management of anal HSIL in this patient group. The ANCHOR trial demonstrated that treating anal HSIL significantly reduces the risk of anal SCC in PLWH, there is therefore an unmet requirement to clarify whether the screening and treatment of HSIL in women with a prior genital HSIL is also beneficial. This review presents the current evidence supporting the screening, treatment, and surveillance of anal HSIL in high-risk women with a previous history of genital HSIL and/or SCC.

New screening strategy combining anal PAP and HPV tests for HPV-related anal cancer: a prospective, single center study

PURPOSE

The objective of this study was to evaluate the performance of a combined approach of liquid-based anal cytology and HPV testing in predicting patients who should undergo high-resolution anoscopy (HRA) for the early detection of anal cancer and anal intraepithelial neoplasia (AIN)-2 +.

METHODS

Prospective single-center quality improvement study. We consecutively enrolled men who had sex with men (MSM) attending our sexually transmitted disease clinic to undergo anal Pap and HPV tests. All patients with an abnormal anal Pap test result and/or positive HPV test result underwent HRA.

RESULTS

We enrolled 217 MSM, 80 HIV-positive patients, and 137 HIV-negative patients. Cytology showed a sensitivity of 100%, specificity of 64,1%, accuracy of 66.7%, positive predictive value (PPV) of 15,7% and negative predictive value (NPV) of 100% for the detection of AIN-2+. The high-risk (HR)-HPV test showed a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 36.4%, 40%, 9.4%, and 100%, respectively. The combination of abnormal cytology with identification of infection by at least one HR-HPV strain on the HPV test had a sensitivity of 100%, specificity of 73%, accuracy of 74.6%, PPV of 19.1%, and NPV of 100%.

CONCLUSION

Anal HR-HPV testing, complementary to cytology, improves the diagnostic accuracy of screening for anal cancer.

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.

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.

Prevention and Screening of HPV Malignancies

It is estimated that 5% of the global cancer burden, or approximately 690,000 cancer cases annually, is attributable to human papillomavirus (HPV). Primary prevention through prophylactic vaccination is the best option for reducing the burden of HPV-related cancers. Most high-income countries (HICs) have introduced the HPV vaccine and are routinely vaccinating adolescent boys and girls. Unfortunately, although they suffer the greatest morbidity and mortality due to HPV-related cancers, many lower- and middle-income countries (LMICs) have been unable to initiate and sustain vaccination programs. Secondary prevention in the form of screening has led to substantial declines in cervical cancer incidence in areas with established screening programs, but LMICs with absent or inadequate screening programs have high incidence rates. Meanwhile, HICs have seen incidence rates of anal and oropharyngeal cancers rise owing to the limited availability of organized screening for anal cancer and no validated screening options for oropharyngeal cancer. The implementation of screening programs for individuals at high risk of these cancers has the potential to reduce the burden of cervical cancer in LMICs, of anal and oropharyngeal cancers in HICs, and of anal cancer for highly selected HIV+ populations in LMICs. This review will discuss primary prevention of HPV-related cancers through vaccination and secondary prevention through screening of cervical, anal, and oropharyngeal cancers. Areas of concern and highlights of successes already achieved are included.

High-risk human papillomavirus test in anal smears: can it optimize the screening for anal cancer?

OBJECTIVE

The current method for screening anal cancer is anal cytology, which has low sensitivity. Since high-risk human papillomavirus (HR-HPV) is associated with almost 90% of cases of anal cancer, the objective of this study is to evaluate whether testing for HR-HPV can optimize the screening.

DESIGN

Prospective study with patients enrolled in a screening program for anal dysplasia. Considering high-resolution anoscopy (HRA)-guided biopsy as the gold standard for diagnosis of high-grade squamous intraepithelial lesions, the diagnostic performance of anal cytology, HR-HPV testing, and the combination of both was calculated.

SETTINGS

A single center for anal dysplasia.

PARTICIPANTS

A total of 364 patients (72% males, 82% HIV-positive).

INTERVENTION

Patients underwent anal cytology, HR-HPV test, and HRA-guided biopsy of the anal canal.

MAIN OUTCOME MEASURES

Ability of cytology and HR-HPV test (individually and combined) to detect high-grade squamous intraepithelial lesions, and analysis of the cost of each diagnostic algorithm.

RESULTS

Cytology alone was the cheapest approach, but had the lowest sensitivity [59%, 95% confidence interval (CI) 46-71%], despite of highest specificity (73%, 95% CI 68-78%). Cotesting had the highest sensitivity (85%, 95% CI 74-93%) and lowest specificity (43%, 95% CI 38-49%), and did not seem to be cost-effective. However, HR-HPV testing can be used to triage patients with normal and atypical squamous cells of undetermined significance cytology for HRA, resulting in an algorithm with high sensitivity (80%, 95% CI 68-89%), and specificity (71%, 95% CI 65-76%), allied to a good cost-effectiveness.

CONCLUSION

HR-HPV testing is helpful to optimize the screening in cases of normal and atypical squamous cells of undetermined significance cytology.

A 2020 update of anal cancer: the increasing problem in women and expanding treatment landscape

INTRODUCTION

Anal cancer is a rare malignancy with increasing incidence, notably in women. This disease is highly associated with HPV infection and its incidence and mortality are currently rising. Most patients present with localized disease which has a high survival after definitive treatment with chemoradiation. For patients who develop metastatic disease or present with this de novo, survival is poor.

AREAS COVERED

This review provides a summary of current literature on anal cancer. With a focus on women, this includes current epidemiological trends, role of HPV, and the current and future treatment landscape, including HPV vaccination and immunotherapy. Screening currently focusses on HIV-positive men, missing most female cases. In curative disease, trials are investigating treatment de-intensification in good prognostic groups. Immunotherapy is showing early promise in the advanced disease setting.

EXPERT OPINION

Similar to cervical cancer, anal cancer is strongly associated with HPV, and therefore, broader implementation of screening programs may reduce its incidence. HPV vaccination is expected to reduce the development of (pre)malignant anal lesions. The emergence of biomarkers will assist patient treatment selection, allowing optimal balance of treatment efficacy and morbidity. It is hoped that new treatment approaches, including immunotherapy, will improve outcomes. International collaboration is needed.

Treatment efficacy for human papillomavirus-related anal squamous cell dysplasia in an under-represented population: human immunodeficiency-negative, non-men having sex with men, and non-transplant population

AIM

Human papillomavirus (HPV)-related anal squamous cell dysplasia has been well-reported in high-risk (HR) patients [human immunodeficiency virus (HIV)-positive, men having sex with men (MSM) or immune-suppressed transplant recipients]. However, data are extremely limited for all other patients. This study reports treatment outcomes for HPV-related dysplasia in a population of non-HR patients.

METHOD

A retrospective study was performed to review treatment efficacy in non-HR patients diagnosed with anal dysplasia or superficially invasive squamous cell carcinoma of the anus (SISCCA) with at least 12-months' follow-up; HR patients were excluded. Medical records were reviewed for demographics, pathology, cytopathology, treatment and recurrences.

RESULTS

Forty-one patients were identified (34 women). The median age at diagnosis was 58 years (range 26-85) and median follow-up was 26 months (range 12-51). At diagnosis, 36 patients had anal dysplasia and five patients had SISCCA. Treatment outcomes (resolved versus recurrent) differed between treatment modalities (P = 0.014). Topical and fulguration-only treatment modalities were superior to wide local excision (WLE) (P < 0.006 and P < 0.008, respectively). Fourteen (39%) patients had recurrent dysplasia at a median of 14 months (range 4-62); eight patients developed a second recurrence at a median of 14 months (range 11-26). No SISCCA patient had a recurrence, but two patients progressed to anal cancer after treatment.

CONCLUSION

The behaviour of anal dysplasia reported in this under-represented, small group of non-HR patients reveals that treatment for anal dysplasia is not necessarily a single event and nonexcisional treatments may be favourable to WLE. Though the true denominator of this population is unknown, treatment may not prevent the recurrence of dysplasia or progression to cancer, warranting close follow-up.

Prevalent, persistent anal HPV infection and squamous intraepithelial lesions: Findings from a cohort of men living with HIV in South Africa

Objective

To estimate the prevalence, incidence and persistence of anal HPV infection and squamous intra-epithelial lesions (SILs) among men living with HIV (MLHIV), and determine their risk factors.

Methods

We enrolled MLHIV ≥18 years, who attended 6-monthly visits for 18 months. Socio-behavioural data were collected by questionnaire. Clinicians collected blood sample (CD4+ count and HIV plasma viral load), anal swabs (HPV DNA testing) and anal smears (Bethesda classification) at each visit. HPV DNA testing and classification of smears were done at enrolment and last follow-up visit (two time points). Factors associated with persistent anal HPV infection and SILs were evaluated with generalized estimating equations logistic regression and standard logistic regression respectively.

Results

Mean age of 304 participants was 38 (Standard Deviation, 8) years; 25% reported >1 sexual partner in the past 3 months. Only 5% reported ever having sex with other men. Most (65%) participants were taking antiretroviral treatment (ART), with a median CD4+ count of 445 cells/μL (IQR, 328–567). Prevalence of any-HPV infection at enrolment was 39% (88/227). In total, 226 men had anal HPV DNA results at both enrolment and final visits. Persistence of any-anal HPV infection among 80 men who had infection at enrolment was 26% (21/80). Any persistent anal HPV infection was more frequent among MLHIV with low CD4+ count (<200 vs. >500 cells/μL; aOR = 6.58; 95%CI: 2.41–17.94). Prevalence of anal SILs at enrolment was 49% (118/242) while incidence of SILs among MLHIV who had no anal dysplasia at enrolment was 27% (34/124). Of the 118 men who had anal dysplasia at enrolment, 15% had regressed and 38% persisted by month 18. Persistent anal HPV infection was associated with persistent SILs (aOR = 2.95; 95%CI: 1.08–10.89). ART status or duration at enrolment were not associated with persistent anal HPV infection or persistent SILs during follow-up.

Conclusion

In spite of a high prevalence of anal HPV, HIV-positive heterosexual men have a low burden of anal HPV related disease. HPV vaccine and effective ART with immunological reconstitution could reduce this burden of infection.

Recommendations Favoring Anal Cytology as a Method for Anal Cancer Screening: A Systematic Review

Clinicians are increasingly facing the decision of performing anal cancer screening in high-risk groups. Anal cytology is commonly the first approach. We systematically reviewed recommendations favoring anal cytology for anal cancer screening. Three databases were searched: PubMed, Scopus, and Embase, from January 2007 to 12 September 2019. The references cited by the retrieved articles and the websites of relevant organizations were also searched without language restrictions. Studies reporting guidelines from regional or national societies, institutes, or groups were included. Eight papers met the inclusion criteria and were selected, five were from the United States of America (USA) and three from Europe. There were no national recommendations published. There was one guideline specifically for solid-organ transplant recipients. The other seven targeted HIV-positive patients, with HIV-positive men who have sex with men (MSM) included as a screening group in all of these. Two recommendations favored screening in all HIV-positive patients. Five recommendations targeting HIV-positive patients made considerations about the cytology follow-up, recommending at least annual cytology in case of a normal result, and in case of squamous cytological abnormalities, a referral for anoscopy/high-resolution anoscopy. There were no recommendations for upper and lower age limits for screening. In conclusion, several societies recommend anal cancer screening using anal cytology in HIV-positive MSM patients. There is a lack of screening recommendations for other high-risk groups, with only one society recommending screening in transplant recipients.

Cytology in Anal Cancer Screening: Practical Review for Clinicians

The incidence and mortality of anal squamous cell carcinoma (SCC) are expected to continue to increase in the next 20 years. High-risk groups for anal SCC, i.e., human immunodeficiency virus (HIV)-positive patients, men who have sex with men (MSM), women with previous genital neoplasia, and solid-organ transplant recipients, have been identified. HIV-positive MSM have the highest risk, and some societies have advocated for anal cancer screening to be done in this population. Screening for anal SCC follows the same principles as that for cervical cancer since there are similarities between the two types of cancers. Anal cytology has been recommended as an initial screening method for high-risk groups, e.g., HIV-positive MSM. Normally, the cytology is liquid based and collected blindly by a clinician using a Dacron swab and it is especially used for internal lesions detection. The sensitivity to predict anal high-grade squamous intraepithelial lesions is higher in immunosuppressed patients with a high burden of the disease. The report should include the classification, normally according to the Bethesda terminology and the sample adequacy, in a manner similar to that for cervical cytology. In cases involving unsatisfactory samples, it is important to repeat the procedure given the prevalence of anal squamous cytological abnormalities in follow-up cytology procedures. The absence of transformation zone cells in anal cytology seems to increase the risk of false-negative results.