Management of anal squamous intraepithelial lesions

Human Papilloma Virus Infection and Anal Squamous Intraepithelial Lesions

This article addresses the natural history of the human papilloma virus (HPV) infection to anal squamous intraepithelial lesions, and onto squamous cell carcinoma of the anus. This article provides overviews of the virology, pathophysiology, nomenclature, classification, historical terms, risk factors, clinical evaluation, differential diagnosis, and treatment of HPV infection and its sequelae.

Accuracy of Anal Cytology for Diagnostic of Precursor Lesions of Anal Cancer: Systematic Review and Meta-analysis

BACKGROUND

Anal canal carcinoma is relevant because it commonly occurs in high-risk groups, and its incidence has been increasing.

OBJECTIVE

This study evaluated the accuracy of anal cytology in the screening of precursor lesions of anal cancer, compared with histopathologic examination as the reference, in all subjects and in men who have sex with men, HIV-infected men and women, and men who have sex with men and HIV-infected subgroups.

DATA SOURCES

The data included studies identified in the MEDLINE, Latin American and Caribbean Health Sciences, Cochrane Library, and Embase electronic databases, as well as in the grey literature. The search terms included anal cancer, anal dysplasia, anal intraepithelial neoplasia, screening, and anal cytology.

STUDY SELECTION

After excluding studies with no histopathological data and those with duplicate and missing data, 34 primary studies were included.

INTERVENTION

Cytology of anal smears was studied.

MAIN OUTCOME MEASURES

Sensitivity, specificity, diagnostic OR, and area under the curve were measured.

RESULTS

A total of 5093 patients were included. The pooled sensitivity of anal cytology was 85.0% (95% CI, 82.0%-87.0%) and pooled specificity was 43.2% (95% CI, 41.4%-45.1%) for the detection of anal intraepithelial neoplasia grade 2 or worse versus anal intraepithelial neoplasia grade 1 and normal when measuring all subjects. The accuracy of anal cytology was higher in the men who have sex with men and HIV-infected and men who have sex with men only subgroups.

LIMITATIONS

This study was limited by its specificity.

CONCLUSIONS

The study results support the hypothesis that cytology is a good test for the screening of anal cancer.

History of High-Resolution Anoscopy

High-resolution anoscopy (HRA) is a form of low-resolution anal microscopy currently utilized in the screening and management of anal squamous dysplasia. No randomized controlled trials, national or international guidelines exist on the use of HRA for this purpose. Much of our understanding of this entity has been adapted from the literature on cervical squamous dysplasia, including the technique of HRA itself. Epidemiologic evidence has shown that the prevalence and incidence of anal dysplasia is highest in HIV-positive populations. The history of this technique parallels the evolution of our understanding of anal dysplasia. To understand the history of the use of HRA and its place in the screening and management of anal squamous dysplasia, we discuss key advances in the understanding of human papillomavirus-related squamous dysplasia. We begin with early reports in the field establishing the link between this virus and squamous dysplasia, through the marked increase in anal cancer seen with the onset of the HIV epidemic, the identification of relevant populations at risk, the performance of the test itself, to its use today.

Prevention of human papillomavirus (HPV)-related tumors in people living with human immunodeficiency virus (HIV)

INTRODUCTION

In comparison to their HIV-negative counterparts, people living with HIV (PLWH) have a higher prevalence of human papillomavirus (HPV) infection in various anatomical sites coupled with increased HPV persistence, higher risk of HPV-related tumors, and faster disease progression. Areas covered: Gender-neutral prevention strategies for HPV-related cancers in PLWH discussed: ABC approach, HPV vaccination, antiretroviral treatment (ART), anal cancer screening, and smoking cessation. Gender specific strategies: cervical cancer screening reduces the incidence and mortality of cervical cancer and circumcision might reduce the risk of HPV infections in men. Expert commentary: HPV-related cancer incidence has not declined (e.g. cervical cancer) and has even increased (e.g. anal cancer) in the ART era, demanding an effective HPV prevention strategy. HPV vaccination should be introduced into national prevention programs worldwide immediately because current prophylactic vaccines are safe, tolerable, and immunogenic in PLWH. HPV vaccine efficacy trials in PLWH are essential to determine the most appropriate immunization schedule. The population most at risk of anal cancer is HIV-positive men who have sex with men, who are not protected by herd immunity if only the female population is vaccinated. Unvaccinated PLWH need enhanced surveillance for early detection of HPV-related cancers and their precursors.

Management of precancerous anal intraepithelial lesions in human immunodeficiency virus-positive men who have sex with men: Clinical effectiveness and cost-effectiveness

BACKGROUND

Human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) are at disproportionately high risk for anal cancer. There is no definitive approach to the management of high-grade squamous intraepithelial lesions (HSIL), which are precursors of anal cancer, and evidence suggests that posttreatment adjuvant quadrivalent human papillomavirus (qHPV) vaccination improves HSIL treatment effectiveness. The objectives of this study were to evaluate the optimal HSIL management strategy with respect to clinical effectiveness and cost-effectiveness and to identify the optimal age for initiating HSIL management.

METHODS

A decision analytic model of the natural history of anal carcinoma and HSIL management strategies was constructed for HIV-positive MSM who were 27 years old or older. The model was informed by the Surveillance, Epidemiology, and End Results-Medicare database and published studies. Outcomes included the lifetime cost, life expectancy, quality-adjusted life expectancy, cumulative risk of cancer and cancer-related deaths, and cost-effectiveness from a societal perspective.

RESULTS

Active monitoring was the most effective approach in patients 29 years or younger; thereafter, HSIL treatment plus adjuvant qHPV vaccination became most effective. When cost-effectiveness was considered (ie, an incremental cost-effectiveness ratio [ICER] < $100,000/quality-adjusted life-year), do nothing was cost-effective until the age of 38 years, and HSIL treatment plus adjuvant qHPV vaccination was cost-effective beyond the age of 38 years (95% confidence interval, 34-43 years). The ICER decreased as the age at HSIL management increased. Outcomes were sensitive to the rate of HSIL regression or progression and the cost of high-resolution anoscopy and biopsy.

CONCLUSIONS

The management of HSIL in HIV-positive MSM who are 38 years old or older with treatment plus adjuvant qHPV vaccination is likely to be cost-effective. The conservative approach of no treatment is likely to be cost-effective in younger patients. Cancer 2017;123:4709-4719. © 2017 American Cancer Society.

Adjuvant HPV vaccination for anal cancer prevention in HIV-positive men who have sex with men: The time is now

IMPORTANCE

Outcomes of treating high-grade squamous intraepithelial lesions (HSIL), a precursor to anal cancer, remain uncertain. Emerging evidence shows that post HSIL treatment adjuvant quadrivalent human papillomavirus (qHPV) vaccination improves the effectiveness of treatment. However, no recommendations exist regarding the use of qHPV vaccine as an adjuvant form of therapy. Our objective was to determine whether post-treatment adjuvant vaccination should be adopted in HIV-infected MSM (individuals at highest risk for anal cancer) on the basis of cost-effectiveness determined using existing evidence or whether future research is needed.

METHODS

We developed a Markov (state-transition) cohort model to assess the cost-effectiveness of post-treatment adjuvant HPV vaccination of 27years or older HIV-infected MSM. We first estimated cost-effectiveness and then performed value-of-information (VOI) analysis to determine whether future research is required by estimating the expected value of perfect information (EVPI). We also estimated expected value of partial perfect information (EVPPI) to determine what new evidences should have highest priority.

RESULTS

With the incremental cost-effectiveness ratio (ICER) of $71,937/QALY, "treatment plus vaccination" was the most cost-effective HSIL management strategy using the willingness-to-pay threshold of 100,000/QALY. We found that population-level EVPI for conducting future clinical research evaluating HSIL management approaches was US$12 million (range $6-$20 million). The EVPPI associated with adjuvant qHPV vaccination efficacy estimated in terms of hazards of decreasing HSIL recurrence was $0 implying that additional data from a future study evaluating efficacy of adjuvant qHPV vaccination will not change our policy conclusion that "treatment plus vaccination" was cost-effective. Both the ICER and EVPI were sensitive to HSIL treatment compliance.

CONCLUSION

Post-treatment adjuvant qHPV vaccination in HIV-infected MSM aged 27 or above is likely to be cost-effective. Use of adjuvant qHPV vaccination could be considered as a potential strategy to reduce rising anal cancer burden among these high-risk individuals.

Prevalence of Anal Dysplasia in Patients With Inflammatory Bowel Disease

BACKGROUND & AIMS

Although the prevalence of anal dysplasia is higher in some immunosuppressed populations, the prevalence in patients with inflammatory bowel disease (IBD) is unknown. We examined the prevalence of abnormal anal cytology among IBD patients, and its relation to the human papilloma virus (HPV).

METHODS

Adults with IBD and age-matched healthy controls (HC) were recruited. IBD patients were categorized as nonimmunosuppressed (IBD-N) or immunosuppressed (IBD-I). Anal Papanicolaou tests were performed for HPV testing and classification by a cytopathologist as follows: negative, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, cancer, or unsatisfactory.

RESULTS

A total of 270 subjects (100 IBD-I, 94 IBD-N, and 76 HC) were recruited. ASC-US were detected in 19 subjects, with a trend toward a higher prevalence among IBD subjects compared with HC (8.8% vs 2.6%; P = .10). The prevalence did not differ with respect to immunosuppression. Crohn's disease (CD) subjects had a higher prevalence of ASC-US compared with others with IBD (P = .02). Among those with CD, female sex and disease duration longer than 10 years were risk factors. There were no cases of low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, or anal cancer in the cohort. HPV was present in 5.3% and 1.5% of subjects with and without ASC-US, respectively (P = .26).

CONCLUSIONS

Although there was a trend toward abnormal anal Papanicolaou tests in IBD subjects compared with HC, there was no difference based on immunosuppression. The presence of HPV did not correlate with abnormal anal cytology. Risk factors associated with this increased trend include female CD subjects and those with a longer duration of CD. ClinicalTrials.gov number: NCT01860963; https://clinicaltrials.gov/ct2/show/NCT01860963.

Targeted ablation of perianal high-grade dysplasia in men who have sex with men: an alternative to mapping and wide local excision

BACKGROUND

Perianal high-grade dysplasia (Bowen disease) is traditionally treated with mapping and wide excision with possible grafting rather than local ablation.

OBJECTIVE

The aim of this study is to examine the results of high-grade perianal dysplasia ablation.

DATA SOURCES

Data for this study were derived from a retrospective chart review at a surgical practice screening and treating patients for high-grade dysplasia between July 1998 and June 2013.

STUDY SELECTION

The patients included were men who have sex with men and are undergoing perianal dysplasia ablation.

INTERVENTION

Ablation of perianal dysplasia with electrocautery, laser, or infrared coagulation was performed.

MAIN OUTCOME MEASURES

The primary outcomes measured were the recurrence of perianal dysplasia postablation and factors affecting recurrence.

RESULTS

Seventy HIV-positive and 11 HIV-negative patients enrolled; the median ages were 44.7 and 42.8 years. Median follow-up times for HIV-positive and HIV-negative patients were 4.62 and 3.53 years, and the median numbers of treatments were 4 and 1, p = 0.004. The median number of lesions treated was 1 for both groups. Only 1 HIV-negative patient had a recurrence 8 months after treatment. For HIV-positive patients, the Kaplan-Meier probability of recurrence at 1, 3, and 5 years was 38% (95% CI 26-50), 59% (95% CI 47-72), and 68% (95% CI 55-81) after the first ablation with no difference for subsequent treatments. HIV-positive patients had a relative risk of perianal high-grade squamous intraepithelial lesions of 3.72 (95% CI 2.10-6.60) compared with HIV-negative patients (p ≤ 0.0001). In multivariate analysis, only each increase in intra-anal high-grade squamous intraepithelial lesions significantly increased recurrence (HR 1.13, 95% CI 1.00-1.28, p = 0.002). Only 3 patients with perianal high-grade squamous intraepithelial lesions did not have canal dysplasia. Perianal cancer developed in 3 after being lost to follow-up.

LIMITATIONS

This is a retrospective analysis of 1 experienced surgeon's results. No precise way exists to accurately determine the size of the disease.

CONCLUSIONS

Perianal dysplasia can be successfully ablated, but recurrence remains high. Almost all patients have anal canal dysplasia. HIV-positive patients are at the greatest risk for disease and recurrence. An increased number of high-grade canal lesions increases recurrence.

Diagnosis, treatment, and prevention of anal cancer

Rare in the general population, anal cancer has reached epidemic proportions among HIV-infected men who have sex with men (MSM). These cancers are human papillomavirus (HPV)-associated, usually HPV type16, and are analogous to cervical cancer. At present, the rates of anal cancer in this group are 10-fold higher than that of cervical cancer occurring in women in the general population. Although there are no national guidelines for screening for anal intraepithelial dysplasia (AIN), many large HIV clinics are now performing anal cytologic screening in their at-risk patients. This paper outlines the current approach to screening for AIN and its management.

Anal anatomy and normal histology

The focus of this article is the anatomy and histology of the anal canal, and its clinical relevance to anal cancers. The article also highlights the recent histological and anatomical changes to the traditional terminology of the anal canal. The terminology has been adopted by the American Joint Committee on Cancer, separating the anal region into the anal canal, the perianal region and the skin. This paper describes the gross anatomy of the anal canal, along with its associated blood supply, venous and lymphatic drainage, and nerve supply. The new terminology referred to in this article may assist clinicians and health care providers to identify lesions more precisely through naked eye observation and without the need for instrumentation. Knowledge of the regional anatomy of the anus will also assist in management decisions.

The changing picture of high-grade anal intraepithelial neoplasia in men who have sex with men: the effects of 10 years of experience performing high-resolution anoscopy

BACKGROUND

Ten years ago, we published findings from anal dysplasia screening in a metropolitan surgical practice where the majority of men who have sex with men had biopsy-proven high-grade anal intraepithelial neoplasia.

OBJECTIVE

This study aimed to determine the effect of 10 years of experience in anal dysplasia screening on the prevalence of high-grade anal intraepithelial neoplasia.

DESIGN

A retrospective chart review was performed of all anal cytology results of 1189 men who have sex with men screened in a 1-year period, with subsequent high-resolution anoscopy and biopsy as necessary.

PATIENTS

The patients studied were men who have sex with men.

MAIN OUTCOME MEASURE

The main outcome measure was biopsy-proven high-grade anal intraepithelial neoplasia.

RESULTS

: There were 315 (37.2%) biopsy-verified instances of high-grade anal intraepithelial neoplasia. Regression analysis determined that age, HIV status, infection by high-risk human papillomavirus, and abnormal cytology results were significant predictors of high-grade anal intraepithelial neoplasia. In a 1-year period, the number of men who have sex with men screened was nearly 7 times greater than in the 2-year period studied 10 years earlier.

LIMITATIONS

We did not separately analyze patients who had previously been treated for high-grade anal intraepithelial neoplasia.

CONCLUSIONS

Severity of cytology and infection with high-risk human papillomavirus are the most significant predictors of high-grade anal intraepithelial neoplasia, underscoring the importance of anal dysplasia screening. Our ability to identify high-grade anal intraepithelial neoplasia has improved with 10 years of experience performing high-resolution anoscopy.