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

Association of body mass index with anal human papillomavirus infection and histologically confirmed high-grade squamous intraepithelial lesions in people who receive services at the Anal Neoplasia Clinic in Puerto Rico

Objective

This study aimed to assess the association of body mass index (BMI) with anal high-risk human papillomavirus (HR-HPV) and biopsy-confirmed histologic anal high-grade squamous intraepithelial lesions (HSIL) among a clinic-based sample of Hispanics in Puerto Rico.

Methods

This cross-sectional study evaluated medical records of adults who received services at the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center between October 2014 and December 2022. The study included 543 records with complete clinical information regarding anal HR-HPV and anal HSIL status. Chi-square and logistic regression analyses were performed.

Results

Mean age of participants was 44.10 ± 13.24 years, 65.2% were men, 71.7% were HIV-infected, 74.4% had anal HR-HPV infection, and 37.9% had biopsy-confirmed HSIL. Regarding BMI, 2.4% were underweight, 31.9% normal weight, and 39.0 % overweight; while 17.3 % had class I, 5.2% class II, and 4.2% class III obesity. No significant association was observed between BMI and anal HR-HPV infection in adjusted analyses. Lower odds of anal HSIL were observed among overweight individuals (OR: 0.63, 95% CI: 0.41 - 0.99) and those with class II/III obesity (OR: 0.48, 95% CI: 0.22 - 1.01) compared to adults with underweight/normal BMI, after adjusting for potential confounders. No significant association was observed for class I obesity.

Conclusion

BMI was not associated with anal HR-HPV infection. Overweight and obese individuals had lower odds of having anal HSIL than adults with underweight/normal BMI. This finding could suggest underdiagnosis of HSIL among overweight/obese individuals, or reduced risk in this group.

Implementation of and Early Outcomes From Anal Cancer Screening at a Community-Engaged Health Care Facility Providing Care to Nigerian Men Who Have Sex With Men

PURPOSE

Anal cancer risk is substantially higher among HIV-infected men who have sex with men (MSM) as compared with other reproductive-age adults, but screening is rare across sub-Saharan Africa. We report the use of high-resolution anoscopy (HRA) as a first-line screening tool and the resulting early outcomes among MSM in Abuja, Nigeria.

METHODS

From August 2016 to August 2017, 424 MSM enrolled in an anal cancer screening substudy of TRUST/RV368, a combined HIV prevention and treatment cohort. HRA-directed biopsies were diagnosed by histology, and ablative treatment was offered for high-grade squamous intraepithelial lesions (HSIL). HRA proficiency was assessed by evaluating the detection of squamous intraepithelial lesions (SIL) over time and the proportion biopsied. Prevalence estimates of low-grade squamous intraepithelial lesions and HSIL with 95% CIs were calculated. Multinomial logistic regression was used to identify those at the highest risk of SIL.

RESULTS

Median age was 25 years (interquartile range [IQR], 22-29), median time since sexual debut was 8 years (IQR, 4-12), and 59% (95% CI, 54.2% to 63.6%) were HIV infected. Rate of detection of any SIL stabilized after 200 screenings, and less than 20% had two or more biopsies. Preliminary prevalence estimates of low-grade squamous intraepithelial lesions and HSIL were 50.0% (95% CI, 44.7% to 55.3%) and 6.3% (95% CI, 4.0% to 9.3%). HIV infection, at least 8 years since anal coital debut, concurrency, and external warts were independently statistically associated with SIL.

CONCLUSION

Proficiency with HRA increased with experience over time. However, HSIL detection rates were low, potentially affected by obstructed views from internal warts and low biopsy rates, highlighting the need for ongoing evaluation and mentoring to validate this finding. HRA is a feasible first-line screening tool at an MSM-friendly health care facility. Years since anal coital debut and external warts could prioritize screening.

A Randomized Clinical Trial of Infrared Coagulation Ablation Versus Active Monitoring of Intra-anal High-grade Dysplasia in Adults With Human Immunodeficiency Virus Infection: An AIDS Malignancy Consortium Trial

BACKGROUND

Anal high-grade squamous intraepithelial lesions (HSILs) ablation may reduce the incidence of invasive cancer, but few data exist on treatment efficacy and natural regression without treatment.

METHODS

An open-label, randomized, multisite clinical trial of human immunodeficiency virus (HIV)-infected adults aged ≥27 years with 1-3 biopsy-proven anal HSILs (index HSILs) without prior history of HSIL treatment with infrared coagulation (IRC). Participants were randomized 1:1 to HSIL ablation with IRC (treatment) or no treatment (active monitoring [AM]). Participants were followed every 3 months with high-resolution anoscopy. Treatment participants underwent anal biopsies of suspected new or recurrent HSILs. The AM participants underwent biopsies only at month 12. The primary end point was complete clearance of index HSIL at month 12.

RESULTS

We randomized 120 participants. Complete index HSIL clearance occurred more frequently in the treatment group than in the AM (62% vs 30%; risk difference, 32%; 95% confidence interval [CI], 13%-48%; P < .001). Complete or partial clearance (clearance of ≥1 index HSIL) occurred more commonly in the treatment group (82% vs 47%; risk difference, 35%; 95% CI, 16%-50%; P < .001). Having a single index lesion, compared with having 2-3 lesions, was significantly associated with complete clearance (relative risk, 1.96; 95% CI, 1.22-3.10). The most common adverse events related to treatment were mild or moderate anal pain and bleeding. No serious adverse events were deemed related to treatment or study participation.

CONCLUSION

IRC ablation of anal HSILs results in more clearance of HSILs than observation alone.

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.

What Is the Risk of Anal Carcinoma in Patients With Anal Intraepithelial Neoplasia III?

BACKGROUND

The risk of anal carcinoma after previous diagnosis of anal intraepithelial neoplasia III is unclear.

OBJECTIVE

The purpose of this study was to estimate the risk of anal carcinoma in patients with anal intraepithelial neoplasia III and to identify predictors for subsequent malignancy.

DESIGN

This was a retrospective review using the Surveillance, Epidemiology, and End Results registry (1973-2014).

SETTING

The study was composed of population-based cancer registries from the United States.

PATIENTS

Patients who were diagnosed with anal intraepithelial neoplasia III were included.

MAIN OUTCOME MEASURES

The primary outcome was rate of subsequent anal squamous cell carcinoma. Predictors for anal cancer were identified using logistic regression and Cox proportional hazard models.

RESULTS

A total of 2074 patients with anal intraepithelial neoplasia III were identified and followed for a median time of 4.0 years (interquartile range, 1.8-6.7 y). Of the cohort, 171 patients (8.2%) subsequently developed anal cancer. Median time from anal intraepithelial neoplasia III diagnosis to anal cancer diagnosis was 2.7 years (interquartile range, 1.1-4.5 y). Fifty-two patients (30.4%) who developed anal carcinoma were staged T2 or higher. Ablative therapies for initial anal intraepithelial neoplasia III were associated with a reduction in the risk of anal cancer (OR = 0.3 (95% CI, 0.1-0.7); p = 0.004). Time-to-event analysis revealed that the 5-year incidence of anal carcinoma after anal intraepithelial neoplasia III was 9.5% or ≈1.9% per year.

LIMITATIONS

The registry did not record HIV status, surveillance schedule, use of high-resolution anoscopy, or provider specialty.

CONCLUSIONS

In the largest published cohort of patients with anal intraepithelial neoplasia III, ≈10% of patients were projected to develop anal cancer within 5 years. Nearly one third of anal cancers were diagnosed at stage T2 or higher despite a previous diagnosis of anal intraepithelial neoplasia III. Ablative procedures were associated with a decreased risk of cancer. This study highlights the considerable rate of malignancy in patients with anal intraepithelial neoplasia III and the need for effective therapies and surveillance. See Video Abstract at http://links.lww.com/DCR/A764.

Testing for Human Papillomavirus Strains 16 and 18 Helps Predict the Presence of Anal High-Grade Squamous Intraepithelial Lesions

BACKGROUND

More than 90% of anal cancers are caused by human papillomavirus, and human papillomavirus strains 16 and 18 are the most oncogenic. Anal high-grade squamous intraepithelial lesions are cancer precursors. Treating these high-grade intraepithelial lesions likely reduces the risk of cancer, but cytology is an imperfect screening test.

OBJECTIVE

The purpose of this study was to determine whether human papillomavirus 16 and/or 18 testing better predicts the presence of high-grade squamous intraepithelial lesions.

DESIGN

In this retrospective study, 894 consecutive patients underwent anal dysplasia screening with digital anorectal examination, anal cytology, high-risk human papillomavirus testing, and high-resolution anoscopy with biopsy. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of each test and for a novel screening protocol. The absolute and relative risk of high-grade squamous intraepithelial lesions for all of the cytology/human papillomavirus combinations were also calculated.

SETTINGS

The study was conducted at a single practice specializing in anal dysplasia.

PATIENTS

Ninety-two percent of participants were men who have sex with men. Forty-four percent were HIV-positive individuals who were well controlled on antiretroviral therapy. The median age was 50 years.

MAIN OUTCOME MEASURES

The presence of high-grade squamous intraepithelial lesions as a function of human papillomavirus and the cytology results were measured.

RESULTS

High-risk human papillomavirus testing alone demonstrated better sensitivity (96% vs 89%; p = 0.03) and negative predictive value (99% vs 96%; p = 0.008) over cytology. Human papillomavirus 16/18 testing increased specificity (48% to 71%; p < 0.0001) and positive predictive value (24% to 37%; p = 0.003) over testing for all of the high-risk strains. For each cytology category, high-grade squamous intraepithelial lesions were more prevalent when human papillomavirus 16/18 was detected. Benign cytology with 16/18 had a 31-fold increased risk of high-grade squamous intraepithelial lesions.

LIMITATIONS

This study was conducted in a single private practice specializing in anal dysplasia screening with a mostly male population, and results might not be generalizable.

CONCLUSIONS

Testing of high-risk human papillomavirus strains 16/18 improves specificity and positive predictive value over cytology for anal dysplasia screening. Patients testing positive for strains 16/18 are at a high risk for high-grade squamous intraepithelial lesions and should undergo high-resolution anoscopy regardless of the cytology result. See Video Abstract at http://links.lww.com/DCR/A654.

Determinants of high-grade anal intraepithelial lesions in HIV-positive MSM

OBJECTIVE

To assess determinants for histologically proven high-grade anal intraepithelial lesions (hHSIL) in HIV-positive men who have sex with men (MSM), a population at high-risk of HPV-related anal cancer.

DESIGN

APACHES is a prospective study of anal HPV and related-lesions in 513 HIV-positive MSM aged at least 35 years in six centres across France.

METHODS

At baseline, participants underwent high-resolution anoscopy (HRA) with biopsy of suspicious lesions, preceded by anal swabs for liquid-based cytology, p16/Ki67 immunostaining, and HPV DNA. hHSIL diagnosis was established by histopathological review panel consensus, and determinants assessed by logistic regression.

RESULTS

Baseline hHSIL prevalence was 10.4% and did not differ significantly by age, sexual behaviour or HIV/immunodeficiency markers. hHSIL prevalence was significantly elevated in participants who smoked (ORadj = 2.6, 95% CI 1.3-5.5) or who, in concurrent anal swabs, had ASCUS/LSIL (3.6, 95% CI 1.4-9.3) or ASC-H/HSIL (22.2, 95% CI 6.8-72.6) cytologic abnormalities, p16/Ki67 dual positivity (3.4, 95% CI 1.5-7.5), or non-HPV16 HR (13.0, 95% CI 1.7-102), but most notably, HPV16 (46.3, 95% CI 6.1-355) infection. Previous diagnosis of low-grade (2.3, 95% CI 1.0-5.4) or high-grade (3.8, 95% CI 1.5-9.9) anal lesion also conveyed higher hHSIL risk. After controlling for patient-specific determinants, there remained significant centre-specific effects, most clearly in higher risk groups (HPV16-positive participants: 31.3% hHSIL in centres A-D versus 5.1% in centres E and F, P < 0.01).

CONCLUSION

Anal cytology and HPV16 infection are potentially useful determinants of hHSIL risk in HIV-positive MSM, but HIV/immunodeficiency-related variables appear not to be. Controlling for patient-specific hHSIL determinants highlights variability in HRA practice across diverse clinical settings and the need for better standardization of this difficult procedure.

Anal cytology, histopathology and anoscopy in an anal dysplasia screening program: is anal cytology enough?

BACKGROUND AND AIM

The human papilloma virus is the leading cause of anal squamous cell carcinoma. Cytological screening may reduce the associated morbidity and mortality. The aim of the study was to estimate the agreement between anal cytological examination, histopathology and anoscopic visual impression.

METHODS

A prospective study of patients who underwent anal dysplasia screening between 2011 and 2015, in a proctology clinic of a tertiary referral center.

RESULTS

During the study period, 141 patients (91% men, 87% with HIV infection) underwent 175 anal cytology tests. Of these, 33% were negative for intraepithelial lesions or malignancy (NILM), 22% were atypical squamous cells of uncertain significance (ASCUS), 33% were low-grade squamous intraepithelial lesion (LSIL) and 12% were high-grade squamous intraepithelial lesion (HSIL). With regard to anoscopic visual impression, 46% of patients had no lesions and excision/biopsy of the identified lesions was performed in the remaining patients. The weighted kappa-agreement between abnormal cytological results and anoscopic visual impression was moderate (k = 0.48). The weighted kappa-agreement between simultaneous anal cytological examinations and anal histopathologic findings was low (kappa = 0.20). With regard to the histological examination of cases with HSIL or superficially invasive squamous cell carcinoma, 64% of patients had dysplasia of a lower grade according to the cytological analysis (6 ASCUS, 18 LSIL and 4 NILM).

CONCLUSION

There was a poor correlation between anal cytology, histopathology and anoscopic visual impression and a high number of histological studies of HGD that were of a lower dysplastic degree according to the cytological examination. Therefore, anal cytology screening should not be used as the sole method of anal dysplasia screening.

Preliminary results of a screening program for anal cancer and its precursors for HIV-infected men who have sex with men in Vigo-Spain

BACKGROUND

Men who have sex with men (MSM) infected with human immunodeficiency virus (HIV) have the highest risk of developing anal cancer (AC). The objective of this study was to describe our screening implementation program in this population, and report the prevalence of human papillomavirus (HPV) anal infection, and cytological and histological findings in a Spanish medium-size community (Vigo, Spain).

METHOD

Prospective cohort analysis of 240 HIV-infected MSM. Cellular anal sample and high risk HPV (HR-HPV)-tests were performed to study cytological changes and HPV genotyping. High resolution anoscopy (HRA) was performed in 209 patients. Results were analyzed with respect to epidemiological, clinical and analytical factors.

RESULTS

Of 209 patients selected for HRA, the prevalence of HR-HPV anal infection, cytological and histological alterations was 85.6%, 47.5%, and 39.8%, respectively. Sensitivity and specificity for ≥ ASCUS (atypia of squamous cells of undetermined significance) cytology in relation to histological alterations were 61% and 85%, (OR: 8.7; IC 95%: 4.4-17.2), respectively. Observed concordance between high-grade squamous intraepithelial lesion (HSIL) cytology and HSIL anal intraepithelial neoplasia types 2 and 3 (AIN-2/3) histology was 64% (OR: 11.4; IC 95%: 3.6-36.7). One patient with HSIL cytology presented a prevalent anal squamous carcinoma.

CONCLUSIONS

HRA was feasible with similar results to relevant groups. There was a high prevalence of anal HR-HPV infection, and cytological and histological alterations.

Histological outcomes of anal high-grade cytopredictions

BACKGROUND

Longitudinal studies of histological outcomes after anal cytological screening in men who have sex with men (MSM) are rare. This study measured the positive predictive values (PPVs) of each level of baseline cytological abnormality in MSM in Sydney, Australia, over a 12-month period.

METHODS

The Study of the Prevention of Anal Cancer is a 3-year prospective study of the natural history of anal human papillomavirus infection in MSM at least 35 years old. For each participant with a baseline cytological abnormality, the worst histology was recorded at the baseline high-resolution anoscopy and at 6 and 12 months. PPVs for a histological high-grade squamous intraepithelial lesion (HSIL) diagnosis were calculated for each level of baseline cytological abnormality at each time point.

RESULTS

Among 424 men who completed 3 visits, the PPV of a cytological HSIL increased from 71.6% at the baseline to 86.4% at 6 months and to 92.6% at 12 months (P < .001). For cytological atypical squamous cells, cannot rule out high-grade squamous intraepithelial lesion (ASC-H), the PPV increased from 51.5% at the baseline to 69.7% at 6 months and to 75.8% at 12 months (P = .004). At each time point, the PPV of a cytological HSIL was significantly higher than the PPV of ASC-H. The PPV of low-grade cytology reports was significantly lower than the PPV of ASC-H at each time point.

CONCLUSIONS

In a cohort of MSM, a baseline histological HSIL diagnosis after an HSIL cytoprediction is high, and it increases with further examinations over the course of 12 months. Lower levels of cytological abnormalities have significantly lower PPVs. These data can inform patient management and the quality assessment of each aspect of the screening pathway. Cancer Cytopathol 2018;126:136-44. © 2017 American Cancer Society.

2016 IANS International Guidelines for Practice Standards in the Detection of Anal Cancer Precursors

OBJECTIVES

To define minimum standards for provision of services and clinical practice in the investigation of anal cancer precursors.

METHODS

After initial face to face meetings of experts at the International Papillomavirus meeting in Lisbon, September 17 to 21, 2015, a first version was drafted and sent to key stakeholders. A complete draft was reviewed by the Board of the International Anal Neoplasia Society (IANS) and uploaded to the IANS Web site for all members to provide comments. The final draft was ratified by the IANS Board on June 22, 2016.

RESULTS

The essential components of a satisfactory high-resolution anoscopy (HRA) were defined. Minimum standards of service provision, basic competencies for clinicians, and standardized descriptors were established. Quality assurance metrics proposed for practitioners included a minimum of 50 HRAs per year and identifying 20 cases or more of anal high-grade squamous intraepithelial lesions (HSILs). Technically unsatisfactory anal cytological samples at first attempt in high-risk populations should occur in less than 5% of cases. Where cytological HSIL has been found, histological HSIL should be identified in ≥ 90% of cases. Duration of HRA should be less than 15 minutes in greater than 90% of cases. Problematic pain or bleeding should be systematically collected and reported by 10% or lesser of patients.

CONCLUSIONS

These guidelines propose initial minimum competencies for the clinical practice of HRA, against which professionals can judge themselves and providers can evaluate the effectiveness of training. Once standards have been agreed upon and validated, it may be possible to develop certification methods for individual practitioners and accreditation of sites.

A trial of radiofrequency ablation for anal intraepithelial neoplasia

PURPOSE

Radiofrequency ablation (RFA) effectively treats esophageal high-grade dysplasia, but its efficacy in treating anal canal high-grade squamous intraepithelial lesions (HSILs) is unsubstantiated. This prospective study assessed the safety and efficacy of applying hemi-circumferential RFA to anal canal HSIL.

METHODS

Twenty-one HIV-negative participants with HSIL occupying ≤ half the anal canal circumference were treated with hemi-circumferential anal canal RFA. Participants were assessed every 3 months for 12 months with high-resolution anoscopy; recurrence in the treatment zone was re-treated with focal RFA.

RESULTS

Twenty-one participants with a mean of 1.7 lesions (range 1-4) enrolled and completed the trial. Six (29 %) participants had recurrent HSIL within the treated hemi-circumference within 1 year. Four participants (19 %) had persistence of an index lesion at 3 months. One (2.9 %) index HSIL persisted again at 12 months. No participants had more than two RFA treatments. KM curve-predicted HSIL-free survival within the treatment zone at 1 year was 76 % (95 % CI 52-89 %). Comparing the first 7 and last 14 participants, the predicted 1-year HSIL-free survivals are 43 % (95 % CI 10-73 %) and 93 % (95 % CI 59-99 %), respectively (p = 0.008), suggesting a learning curve with the treating physician. Multivariable analysis showed decreased recurrence in the last 14 participants (HR 0.02; 95 % CI 0.001-0.63) while increasing BMI increased recurrence (HR 1.43, 95 % CI 1.01-2.01). No participants had device or procedure-related serious adverse events, anal stricture, or heavy bleeding.

CONCLUSIONS

Hemi-circumferential RFA yielded a high rate of anal HSIL eradication in HIV-negative patients at 1 year with minimal adverse events. Lesion persistence was probably related to incomplete initial ablation.

The value of a transformation zone component in anal cytology to detect HSIL

BACKGROUND

In a cytology-based screening program intended to prevent anal cancer, the anal transformation zone (TZ) should be adequately sampled because it is the site most susceptible to the development of the cancer precursor, high-grade squamous intraepithelial lesion (HSIL). An adequate TZ component is defined as comprising at least 10 rectal columnar or squamous metaplastic cells. In the current study, the authors examined whether the presence of a TZ component in anal cytology correlated with the detection of histological HSIL.

METHODS

In a natural history study of anal human papillomavirus infection in homosexual men, all participants underwent liquid-based cytology and high-resolution anoscopy (HRA) with or without biopsy at each visit. True-negative cytology (negative cytology with non-HSIL biopsy or negative HRA), false-negative cytology (negative cytology with HSIL biopsy), and true-positive cytology (abnormal cytology with HSIL biopsy) were compared with regard to the presence or absence of a TZ component.

RESULTS

Of 617 participants, baseline results included 155 true-positive results, 191 true-negative results, and 31 false-negative results. The absence of an adequate TZ component was found to be significantly higher for false-negative (32.3%) than for either true-positive (11.0%; P = .0034) or true-negative (13.1%; P = .0089) results.

CONCLUSIONS

Significantly more false-negative cases lacked a TZ component compared with either true-positive or true-negative cases. TZ cells may be an important indicator of sample quality for anal cytology because, unlike cervical sampling, the anal canal is not visualized during cytology sampling. Cancer Cytopathol 2016;124:596-601. © 2016 American Cancer Society.

The performance of anal cytology as a screening test for anal HSILs in homosexual men

BACKGROUND

Studies regarding the performance of anal cytology in which both the screening test (cytology) and the diagnostic test (high-resolution anoscopy [HRA]) are performed in all members of a screening population are rare. The authors evaluated the performance of liquid-based anal cytology in a cohort of homosexual men in Sydney, New South Wales, Australia.

METHODS

The Study of the Prevention of Anal Cancer (SPANC) is a 3-year prospective study of the natural history of anal human papillomavirus infection in homosexual men aged ≥35 years. At baseline, all participants underwent a liquid-based anal cytology test and HRA at the same clinical visit. Biopsies were obtained for histological assessment if lesions suspicious for human papillomavirus infection were visible during HRA. Using any cytological abnormality as the threshold, the sensitivity, specificity, and positive and negative predictive values were calculated against histologically diagnosed high-grade squamous intraepithelial lesions (HSILs).

RESULTS

Among 617 men recruited, the median age was 49 years (range, 35-79 years) and 35.7% were positive for the human immunodeficiency virus. Overall, the sensitivity of cytology was 83.2%, the specificity was 52.6%, the positive predictive value was 45.8%, and the negative predictive value was 86.7%. Specificity improved with increasing age (P for trend =.041). Sensitivity was significantly higher in men with >1 anal octant of biopsy-confirmed HSIL (92.9% vs 77.7%; P = .010), and in those who had ≥10 metaplastic cells present on their cytology slides (87.5% vs 70.2%; P = .007).

CONCLUSIONS

Anal cytology was found to have a higher specificity in older men while maintaining sensitivity. Sensitivity was higher among those with more extensive HSILs and men with metaplastic cells present on cytology. Cancer Cytopathol 2016;124:415-24. © 2016 American Cancer Society.

Anal cancer and intraepithelial neoplasia screening: A review

This review focuses on the early diagnosis of anal cancer and its precursor lesions through routine screening. A number of risk-stratification strategies as well as screening techniques have been suggested, and currently little consensus exists among national societies. Much of the current clinical rationale for the prevention of anal cancer derives from the similar tumor biology of cervical cancer and the successful use of routine screening to identify cervical cancer and its precursors early in the disease process. It is thought that such a strategy of identifying early anal intraepithelial neoplasia will reduce the incidence of invasive anal cancer. The low prevalence of anal cancer in the general population prevents the use of routine screening. However, routine screening of selected populations has been shown to be a more promising strategy. Potential screening modalities include digital anorectal exam, anal Papanicolaou testing, human papilloma virus co-testing, and high-resolution anoscopy. Additional research associating high-grade dysplasia treatment with anal cancer prevention as well as direct comparisons of screening regimens is necessary to develop further anal cancer screening recommendations.

Prevalence of non-HIV cancer risk factors in persons living with HIV/AIDS: a meta-analysis

OBJECTIVE

The burden of cancer among persons living with HIV/AIDS (PLWHA) is substantial and increasing. We assessed the prevalence of modifiable cancer risk factors among adult PLWHA in Western high-income countries since 2000.

DESIGN

Meta-analysis.

METHODS

We searched PubMed to identify articles published in 2011-2013 reporting prevalence of smoking, alcohol consumption, overweight/obesity, and infection with human papillomavirus (HPV), hepatitis C virus (HCV) and hepatitis B virus (HBV) among PLWHA. We conducted random effects meta-analyses of prevalence for each risk factor, including estimation of overall, sex-specific, and HIV-transmission-group-specific prevalence. We compared prevalence in PLWHA with published prevalence estimates in US adults.

RESULTS

The meta-analysis included 113 publications. Overall summary prevalence estimates were current smoking, 54% [95% confidence interval (CI) 49-59%] versus 20-23% in US adults; cervical high-risk HPV infection, 46% (95% CI 34-58%) versus 29% in US females; oral high-risk HPV infection, 16% (95% CI 10-23%) versus 4% in US adults; anal high-risk HPV infection (men who have sex with men), 68% (95% CI 57-79%), with no comparison estimate available; chronic HCV infection, 26% (95% CI 21-30%) versus 0.9% in US adults; and HBV infection, 5% (95% CI 4-5%) versus 0.3% in US adults. Overweight/obesity prevalence (53%; 95% CI 46-59%) was below that of US adults (68%). Meta-analysis of alcohol consumption prevalence was impeded by varying assessment methods. Overall, we observed considerable study heterogeneity in prevalence estimates.

CONCLUSION

Prevalence of smoking and oncogenic virus infections continues to be extraordinarily high among PLWHA, indicating a vital need for risk factor reduction efforts.

High-resolution anoscopy: Unchartered territory for gastroenterologists?

High-resolution anoscopy (HRA) is a procedure where patients with an increased risk of anal cancer, like men who have sex with men, human immunodeficiency virus infected individuals, transplant patients and women with a history of lower genital tract neoplasia, with abnormal anal cytology results, are submitted to anal and perianal visualization under magnification. This will allow for a better detection of anal high-grade lesions that can be treated, in an effort to prevent anal cancer. Anal cancer screening follows the same principles that cervical cancer screening. During this procedure, an anoscope is inserted and a colposcope is used to examine systematically the squamocolumnar junction, the transformation zone and the perianal skin. Initially the observation is done with no staining and then with the application of acetic acid and Lugol's iodine solution, allowing for better lesion identification and characterization. Any suspicious lesion seen should be carefully evaluated and biopsied. Without HRA only a small percentage of suspicious lesions are identified. High-grade lesions that are detected can be ablated under HRA. This is a challenging exam to perform, with a long learning curve and the number of clinicians performing it is limited, although the growing number of patients that need to been screened. Specific equipment is required, with these patients ideally been followed by a multidisciplinary team, in a reference centre. HRA remains unfamiliar for many gastroenterologists.

Screening for Anal Cancer in Women

OBJECTIVE

The incidence of anal cancer is higher in women than men in the general population and has been increasing for several decades. Similar to cervical cancer, most anal cancers are associated with human papillomavirus (HPV), and it is believed that anal cancers are preceded by anal high-grade squamous intraepithelial lesions (HSIL). Our goals were to summarize the literature on anal cancer, HSIL, and HPV infection in women and to provide screening recommendations in women.

METHODS

A group of experts convened by the American Society for Colposcopy and Cervical Pathology and the International Anal Neoplasia Society reviewed the literature on anal HPV infection, anal SIL, and anal cancer in women.

RESULTS

Anal HPV infection is common in women but is relatively transient in most. The risk of anal HSIL and cancer varies considerably by risk group, with human immunodeficiency virus-infected women and those with a history of lower genital tract neoplasia at highest risk compared with the general population.

CONCLUSIONS

While there are no data yet to demonstrate that identification and treatment of anal HSIL leads to reduced risk of anal cancer, women in groups at the highest risk should be queried for anal cancer symptoms and required to have digital anorectal examinations to detect anal cancers. Human immunodeficiency virus-infected women and women with lower genital tract neoplasia may be considered for screening with anal cytology with triage to treatment if HSIL is diagnosed. Healthy women with no known risk factors or anal cancer symptoms do not need to be routinely screened for anal cancer or anal HSIL.

Are colon and rectal surgeons ready to screen for anal dysplasia? Results of a survey on attitudes and practice

BACKGROUND

Colorectal surgeons are ideal referral sources to screen for and treat high-grade anal dysplasia (high-grade squamous intraepithelial lesion [HSIL]) and anal cancer. Anal cytology and high-resolution anoscopy (HRA) using acetic acid and magnification are optimal methods for screening. We endeavored to determine US colorectal surgeons' attitudes and practices regarding HSIL screening.

METHODS

An Internet-based survey with questions related to clinician demographics and attitudes and practices regarding anal dysplasia was sent to US members of the American Society of Colon and Rectal Surgeons.

RESULTS

Of 1655 requests, 290 (18%) eligible participants responded. Most were white (83%), male (76%), board-certified colorectal surgeons (89%), and graduating medical school after 1990 (54%), almost all treated patients at risk for anal cancer and had read research on HSIL. Approximately one-third of respondents had performed anal cytology, and one-third had performed HRA. When evaluating patients for HSIL in surgery, only 31% use acetic acid with magnification. Of 99 participants who perform HRA, 46% were formally trained, 83% primarily do HRA primarily in the operating room, and 82% use acetic acid with magnification. Knowledge of HSIL risk factors was not associated with screening. Women, more recent graduates, and surgeons with higher percentages of HIV-infected patients were more likely to screen. Screening barriers included no training (52%), not a priority (23%), lack of evidence (21%), and cost (8%).

CONCLUSIONS

American Society of Colon and Rectal Surgeons members responding to the survey by and large do not screen for anal dysplasia. Those that do are often not formally trained and use inadequate technique.

Prevention of anal condyloma with quadrivalent human papillomavirus vaccination of older men who have sex with men

Background

The quadrivalent human papillomavirus vaccine (qHPV) is FDA-approved for use in males 9 to 26 years old to prevent anogenital condyloma. The objective of this study is to determine if qHPV is effective at preventing anal condyloma among men who have sex with men (MSM) aged 26 years and older.

Methods

This post-hoc analysis of a nonconcurrent cohort study evaluated 210 patients without history of anal condyloma and 103 patients with previously-treated anal condyloma recurrence-free for at least 12 months prior to vaccination/time zero. We determined the rate of anal condyloma development in vaccinated versus unvaccinated patients.

Results

313 patients with mean age 42 years were followed for median 981 days. During 773.6 person-years follow-up, condyloma developed in 10 (8.6%) vaccinated patients (incidence of 3.7 per 100 person-years) and 37 (18.8%) unvaccinated patients (incidence 7.3 per 100 person-years; p = 0.05). Multivariable hazards ratio showed that qHPV was associated with decreased risk of anal condyloma development (HR 0.45; 95% CI 0.22–0.92; p = 0.03). History of anal condyloma was associated with increased risk of anal condyloma development (HR 2.28; 95% CI 1.28–4.05; p = 0.005), as was infection with oncogenic HPV (HR 3.87; 95% CI 1.66–9.03; p = 0.002).

Conclusions

Among MSM 26 years of age and older with and without history of anal condyloma, qHPV reduces the risk of anal condyloma development. A randomized controlled trial is needed to confirm these findings in this age group.

Prevalence of abnormal anal cytology and high-grade squamous intraepithelial lesions among a cohort of HIV-infected men who have sex with men

BACKGROUND

The incidence of anal cancer among HIV-infected patients is higher than that in other populations. Anal high-grade squamous intraepithelial lesions are considered precursors to invasive squamous-cell carcinomas and are strongly associated to high-risk human papillomavirus infection.

OBJECTIVE

The aim of this study is to determine the prevalence of anal high-grade squamous intraepithelial lesions through screening based on cytology and high-resolution anoscopy with biopsy in a cohort of HIV-infected men who have sex with men.

DESIGN

This investigation is an observational cross-sectional cohort study.

SETTING

The study was conducted in the HIV unit of a tertiary hospital in Spain.

PATIENTS

Three hundred HIV-infected men who have sex with men participated. Physical examination led to a diagnosis of perianal squamous-cell carcinoma and high-grade squamous intraepithelial lesions in 2 patients who were then excluded.

INTERVENTIONS

Anal liquid cytology was performed. Patients with cytological abnormalities underwent high-resolution anoscopy and biopsy.

MAIN OUTCOME MEASURE

The primary outcome measured was biopsy-proven high-grade squamous intraepithelial lesions.

RESULTS

The median age was 41 ± 10.5 years. The mean and nadir CD4 cell counts were 651 ± 205 cells/mm(3) (interquartile range, 438-800) and 273 ± 205 cells/mm(3) (interquartile range, 131-362). High-risk human papillomavirus was detected in 80.9% of patients, and human papillomavirus 16 was detected in 35.9% of patients. The mean number of human papillomavirus genotypes was 4.6 ± 2.9 (CI, 2-6). Anal cytology was abnormal in 40.9% of patients (n = 122/298; interquartile range, 35.4%-46.6%). High-resolution anoscopy and biopsies were performed in 119 patients. The results of histological analyses were as follows: normal, 7.7% (n = 23); condyloma, 4.3% (n = 13); anal intraepithelial neoplasia 1, 5.7% (n = 17); anal intraepithelial neoplasia 2, 14% (n = 42); and anal intraepithelial neoplasia 3, 8% (n = 24). The overall prevalence of high-grade squamous intraepithelial lesions among patients with abnormal cytology was 54% (95% CI, 45.1%-62.8%). A diagnosis of high-grade squamous intraepithelial lesions was associated with human papillomavirus 16 and human papillomavirus 51 infection, and with detection of a higher number of human papillomavirus genotypes.

LIMITATIONS

High-resolution anoscopy was only performed in patients with abnormal cytology.

CONCLUSIONS

The prevalence of high-risk human papillomavirus infection and high-grade squamous intraepithelial lesions is high in our cohort. Physical examination enabled straightforward diagnosis of perianal high-grade squamous intraepithelial lesions and squamous-cell carcinoma in 2 patients.

Long-term outcome of ablation of anal high-grade squamous intraepithelial lesions: recurrence and incidence of cancer

BACKGROUND

High-grade dysplasia is the anal carcinoma precursor. Clinicians ablate high-grade dysplasia with laser, electrocautery, and infrared coagulation to prevent cancer.

OBJECTIVE

The aim of this study was to determine the long-term effectiveness of high-grade dysplasia ablation and the incidence of cancer.

DESIGN

This study is a retrospective chart review of patients who were treated for high-grade dysplasia from February 1998 until May 2012.

SETTING

This study was conducted in a surgical practice screening patients for anal cancer and high-grade dysplasia.

PATIENTS

The patients identified were HIV-positive and -negative men who have sex with men.

INTERVENTION

The ablation of high-grade dysplasia was performed.

MAIN OUTCOME MEASURES

The primary outcomes measured were the probability of high-grade dysplasia recurrence postablation and the incidence of cancer.

RESULTS

Four hundred fifty-six HIV-positive men who have sex with men (mean age, 45 ± 9 years) and 271 HIV-negative men who have sex with men (mean age, 41 ± 11 years) followed for a median of 2.2 (range, 0.2-13) years underwent high-grade dysplasia ablation by laser, infrared coagulation, and/or electrocautery. Median time to recurrence was 6.8 and 6.9 months for HIV-positive and -negative patients. Kaplan-Meier curves predict a rate of recurrence 1 year after the first ablation for HIV-positive and -negative patients of 53% (95% CI, 49%-58%) and 49% (95% CI, 43%-55%). At 2 and 3 years, the rate of recurrence was 68% (95% CI, 63%-73%) and 77% (95% CI, 7%2-82%) for HIV-positive patients and 57% (95% CI, 51%-64%) and 66% (95% CI, 59%-73%) for HIV-negative patients. The median number of recurrent lesions was ≤2 for HIV-positive patients and ≤1 for HIV-negative patients. Recurrence increased with HIV infection (HR, 1.3; 95% CI, 1.1-1.6) and each additional lesion treated (HR 1.6, 95% CI, 1.1-1.2). Five HIV-positive men who have sex with men developed cancer. The Kaplan-Meier probability of cancer 3 years postablation was 1.97% (95% CI, 0.73%-5.2%).

LIMITATIONS

This is a retrospective study by 1 surgeon who has extensive experience treating anal dysplasia. There was no pathology review, and the type of recurrence cannot be definitively determined because the location could be inaccurate.

CONCLUSIONS

Patients undergoing ablation of intra-anal high-grade dysplasia have high recurrence, but the probability of developing anal cancer is low. HIV infection and increased number of high-grade dysplasias increases the risk of recurrence.

Colposcopy: a global perspective: introduction of the new IFCPC colposcopy terminology

This article describes the current nomenclature of colposcopic findings in the lower genital tract as defined by the International Federation for Cervical Pathology and Colposcopy (IFCPC) and agreed at their Triennial General Meeting in July 2012 in Rio de Janeiro. It builds on previous nomenclature published by the IFCPC over the last two decades and introduces for the first time the concept of transformation zone excision types. Vulval and vaginal colposcopic terminology is described.

High rates of anal dysplasia in HIV-infected men who have sex with men, women, and heterosexual men

OBJECTIVE

To determine rates of anal dysplasia in a cohort of HIV-infected men who have sex with men (MSM), women, and heterosexual men with abnormal anal cytology.

DESIGN/METHODS

We evaluated histologic findings in 728 HIV-infected MSM, women, and heterosexual men referred for high-resolution anoscopy (HRA) after abnormal anal cytology in a single-center cohort study. Using multivariable logistic regression, we evaluated predictors of high-grade squamous intraepithelial lesion (HSIL) histology or invasive carcinoma including age, sexual behavior, receptive anal intercourse (RAI), anogenital warts, smoking status, antiretroviral therapy, CD4 T-cell count, and HIV-1 plasma viral load.

RESULTS

A total of 2075 HIV-positive patients were screened with anal cytology and 62% of MSM, 42% of women, and 29% of heterosexual men had abnormal findings (P <0.001). Of the 728 HIV-infected patients with abnormal anal cytology who underwent HRA, 71% were MSM, 23% women, and 6% heterosexual men. HSIL/cancer was found in 32% of MSM, 26% of women, and 23% of heterosexual men (P = 0.3). There were five cases of anal squamous cell carcinoma (0.7%), four in MSM and one in a heterosexual man. In a multivariable adjusted analysis, biopsy-proven HSIL/cancer was associated with RAI [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.3-3.7]. CD4 T-cell counts more than 500/μl conferred a lower risk of HSIL/cancer (OR 0.5; 95% CI 0.3-0.9).

CONCLUSION

Rates of anal HSIL histology are high in HIV-infected patients of all sexual risk groups with abnormal anal cytology. Consequently, all HIV-infected patients may warrant anal cancer screening.

Distribution of human papillomavirus genotypes in anal cytological and histological specimens from HIV-infected men who have sex with men and men who have sex with women

BACKGROUND

Anal cancer is caused by human papillomavirus (HPV). Moreover, human immunodeficiency virus (HIV) is an additional risk factor for anal cancer. Therefore, when designing preventive protocols for HIV-infected men, it is important to detect high-risk (HR) oncogenic HPV genotypes present in their anal canals. However, most studies have focused only on men who have sex with men (MSM).

OBJECTIVE

To estimate the prevalence of HPV and describe its genotype distribution using anal cytology and histology specimens from HIV-infected populations of MSM and men who have sex with women (MSW).

DESIGN

Crosssectional study of the CARH·MEN cohort.

SETTING

Single-center prospective cohort of HIV-infected men attending the Outpatient HIV Clinic of Hospital Germans Trias i Pujol (Spain), where they undergo annual screening for HPV infection of the anus, penis and mouth.

PATIENTS

Four hundred eighty-three HIV-infected men (341 MSM, 142 MSW) with no current or previous history of anal condylomata.

MAIN OUTCOME MEASURES

HPV genotypes detected (multiplex-PCR), cytology results (Papanicolaou test) and histology results (biopsy-based).

RESULTS

Cytological abnormalities were detected in 40% of MSM (129/321; 95%CI, 35-46) and 20% of MSW (26/131; 95%CI, 13-28) (OR=2.7; 95%CI, 1.7-4.4). All high-grade squamous intraepithelial lesions (HSIL) were positive for HR-HPV in both groups. High-resolution anoscopy was performed in 146 patients (120 MSM, 26 MSW) with abnormal cytological diagnoses. Lesions were visualized in 80 MSM (67%) and 14 MSW (54%) (OR=1.7 [95%CI, 0.7-4.0]). Histological diagnosis was anal intraepithelial neoplasia (AIN)-1 in 51 MSM (64%) and 6 MSW (43%), AIN-2 in 9 MSM (11%) and 3 MSW (21%), AIN-3 in 7 MSM (9%) and 1 MSW (7%), and normal in 13 MSM (16%) and 4 MSW (29%). HPV16 was the most prevalent HR genotype.

LIMITATIONS

Study limitations include its crosssectional design.

CONCLUSIONS

Anal cancer screening should be offered to all HIV-infected men, regardless of their sexual orientation.

Human papillomavirus genotype attribution and estimation of preventable fraction of anal intraepithelial neoplasia cases among HIV-infected men who have sex with men

BACKGROUND

The prevention of human papillomavirus (HPV)-induced anal cancer in high-risk populations such as human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) remains an urgent priority, given rising incidence rates despite widespread antiretroviral therapy use.

METHODS

HPV genotypes and anal disease prevalence, by cytology and histopathologic findings, were evaluated among 363 HIV-infected MSM. We modeled fractions of high-grade anal intraepithelial neoplasia (HGAIN) attributable to individual carcinogenic HPV genotypes and estimated the range of the proportion of HGAIN cases potentially preventable by prophylactic HPV vaccines.

RESULTS

HPV16 was the most common genotype overall (26.4% of cases) and among HGAIN cases (55%). Prevalence of multiple (≥ 2) carcinogenic HPV genotypes increased from 30.9% in cases of AIN grade <1 to 76.3% in cases of AIN grade 3 (P(trend) < .001). The fractions of HGAIN cases attributable to carcinogenic HPV16/18 targeted by currently licensed bivalent and quadrivalent HPV vaccines ranged from 12% to 61.5%, and the fractions attributable to carcinogenic HPV16/18/31/33/45/52/58 targeted by an investigational nonavalent HPV vaccine ranged from 39% to 89.4%.

CONCLUSIONS

Our analytical framework allows estimation of HGAIN cases attributable to individual HPV genotypes in the context of multiple concurrent HPV infections, which are very common among HIV-infected MSM. Our results suggest that licensed and investigational HPV prophylactic vaccines have the potential to prevent a substantial proportion of HGAIN cases in this population.

Human papillomavirus genotyping, human papillomavirus mRNA expression, and p16/Ki-67 cytology to detect anal cancer precursors in HIV-infected MSM

OBJECTIVE

Anal cancer incidence is high in HIV-infected MSM. Screening for anal intraepithelial lesions and cancers is performed at specialized clinics and relies on high-resolution anoscopy (HRA) and anal cytology. Both approaches have limited reproducibility and sensitivity for detecting anal cancer precursors. We evaluated biomarkers for human papillomavirus (HPV)-related disease in a population of HIV-infected MSM.

METHODS

A cross-sectional screening study with passive follow-up included 363 MSM followed at a HIV/AIDS clinic. All men had anal cytology samples taken and were evaluated using HRA and anal biopsies. Using a composite endpoint of biopsy results and cytology, we compared the performance of HPV16/18 genotyping, HPVE6/E7 mRNA expression, and p16/Ki-67 cytology to detect high-grade anal intraepithelial neoplasias (AINs).

RESULTS

For all biomarkers analyzed, there was a significant trend of increasing percentage of men testing positive with increasing severity of disease (P < 0.001). HPV DNA testing had the highest sensitivity for anal intraepithelial neoplasia grade 2 and anal intraepithelial neoplasia grade 3 (AIN3), followed by p16/Ki-67, HPVE6/E7 mRNA testing, and HPV16/18 genotyping. The highest Youden's index was observed for HPVE6/E7 mRNA testing, followed by HPV16/18 genotyping, p16/Ki-67 cytology, and HPV DNA testing. Increasing the threshold for positivity of p16/Ki-67 to five or more positive cells led to significantly higher specificity, but unchanged sensitivity for detecting AIN3.

CONCLUSION

Molecular features of anal disease categories are similar to those of corresponding cervical lesions. Biomarkers evaluated for cervical cancer screening may be used for primary anal cancer screening or to decide who should require immediate treatment vs. expectant management.

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.

Electrocautery ablation of high-grade anal squamous intraepithelial lesions in HIV-negative and HIV-positive men who have sex with men

BACKGROUND

Anal squamous cell carcinoma (ASCC) incidence has been rising over the past decade, most dramatically in HIV-positive men who have sex with men (MSM). We aimed to identify a novel in-office approach for ablating high-grade anal intraepithelial neoplasia (HGAIN), the believed precursor lesion to ASCC.

MATERIALS AND METHODS

We performed a retrospective analysis of medical records from a New York City surgical practice, identifying patients with HGAIN treated with electrocautery ablation (ECA) and followed for at least 5 months with high-resolution anoscopy, biopsies, and/or cytology. We sought to determine HGAIN recurrence and progression to ASCC after ECA.

RESULTS

Two hundred thirty-two MSM, 132 HIV positive and 100 HIV negative, with median follow-up of 19.0 and 17.5 months, respectively, met inclusion criterion. In HIV-negative and HIV-positive MSM, the probability of curing a lesion after first ECA was 85% and 75%, respectively. Over follow-up, 53% of HIV-negative and 61% of HIV-positive patients recurred. After first and second ECA, HIV-positive MSM were 1.28 times (P = 0.16) and 2.34 times (P = 0.009) more likely to recur than HIV-negative MSM. The majority of recurrence was due to development of additional lesions at untreated sites (metachronous recurrence). One patient (0.4%) developed ASCC. At last visit, 83% of HIV-negative and 69% of HIV-positive patients were HGAIN free.

CONCLUSIONS

ECA is an effective treatment for HGAIN, with fewer patients progressing to ASCC than predicted with expectant management. HIV-positive patients are significantly more likely to recur than HIV-negative patients.

Evaluation of the hybrid capture 2 assay for detecting anal high-grade dysplasia

Hybrid Capture 2 (HC2) Human Papillomavirus (HPV) DNA Test® is FDA approved and is a proven aid in detecting HPV infections of the cervix and as an aid in diagnosing, with cytology, cervical disease. A prospective feasibility study was conducted to determine if HC2 testing has utility when screening for high-grade anal dysplasia (AIN2+). We enrolled 298 patients (45% HIV+) who had AIN2+ screening with cytology, histology and HC2 testing for two specimens: a swab into liquid-based cytology medium and either a swab or a brush collection in specimen transport medium (STM). High-resolution anoscopy was performed on all patients with biopsy of AIN2+ suspicious lesions. Cytology was benign (42%), atypical squamous cells of undetermined significance (30%), low-grade squamous intraepithelial lesion (18%), high-grade squamous intraepithelial lesion (1%), ASCUS possibly high-grade dysplasia (1.7%) and nondiagnostic (7%) and 36% had AIN2+ histology. Sensitivity and specificity for predicting AIN2+ histology for any abnormal cytology were 77 and 52%, whereas HC2 sensitivity and specificity were 91 and 40% (p = 0.005 for sensitivity), respectively. There was no significant difference in HC2 sensitivity or specificity between brush and swab or STM and residual cells from cytology. AIN2+ was found in 20% of patients with benign cytology. Only nine AIN2+ specimens were HC2-. This prospective study indicates that HC2 may be useful when screening for anal dysplasia; however, a larger study is recommended.

Comparison of the performance of anal cytology and cervical cytology as screening tests

Cervical cytology screening has a long history and has successfully reduced the impact of cervical cancer in many countries. Anal cytology is a relative newcomer and anal screening is currently offered in only a few centres around the world. Many questions need to be answered before anal screening is more widely adopted. While there are many similarities between cervical and anal squamous cell carcinoma, there are also important differences: differences in the prevalence of disease, in the ‘at-risk’ target populations and possibly in the robustness of the reference standard of biopsy. The performance of cytology as a screening test in the literature varies widely but it is essential to understand that some of this variability is due to differences in the definitions of key parameters in the various studies. For cervical screening, estimates of sensitivity have ranged from 19% to 94% and specificity from 94% to 98%. For anal screening, data are fewer and more limited. Estimates of the sensitivity of anal cytology in men who have sex with men and HIV-positive populations have ranged from 55% to 87% and specificity from 37% to 76%. Ultimately, rather than comparing anal with cervical cytology, it may be more helpful to assess the value of anal cytology independently through well designed trials.