Comparing Anal Cancer Screening Algorithms Using Cytology and HPV DNA Testing in Three High-risk Populations

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

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

Evaluation of dual p16/Ki-67 immunostaining on anal cytology specimens

INTRODUCTION

Dual immunostaining for p16/Ki67 is FDA-approved for use on liquid-based cervical cytology specimens; however, the utility of dual staining in anal cytology especially for ASCUS risk stratification is not well established.

METHODS

We investigated dual staining performance on anal cytology specimens and correlated with subsequent cytologic interpretation, high-risk HPV status, and anal biopsy results. Dual staining for p16/Ki-67 was performed on all liquid-based anal cytology specimens from December 2021 to June 2022 (n = 43).

RESULTS

Three patients had high grade squamous intraepithelial lesion (HSIL/AIN2-3) on biopsy; dual staining was positive in all three cases. All HR-HPV negative cases were negative for dual staining. Among the 12 ASCUS samples with subsequent anal biopsy results all also had HR-HPV testing. Due to small sample size of cases with squamous intraepithelial lesion (SIL) diagnosed on biopsy, the sensitivity and positive predictive value was not calculated. However, the specificity and negative predictive value of p16/Ki-67 dual staining for SIL of any grade on biopsy were 1 (95% CI: 0.66-1) and 0.9 (95% CI: 0.65-0.97) respectively, whereas the specificity and negative predictive value of HR-HPV testing for SIL of any grade on biopsy were 0.44 (95% CI: 0.14-0.79) and 0.8 (95% CI: 0.41-0.96) respectively.

CONCLUSION

Dual p16/Ki-67 staining indicates transforming HPV infection and could help serve as an ancillary test for risk stratification for atypical anal cytology specimens. Among ASCUS samples, dual staining was specific for SIL of any grade with a high negative predictive value and therefore could be useful in clinical practices with limited availability for follow-up care.

Prevalence of Anal Human Papillomavirus Infection and Anal High-Grade Squamous Intraepithelial Lesions Among Men Who Have Sex With Men 50 Years and Older Living With or Without HIV

BACKGROUND

Anal cancer is caused by human papillomavirus (HPV), particularly HPV-16, and is preceded by anal high-grade squamous intraepithelial lesions (HSILs). The incidence of anal cancer is highest among men who have sex with men (MSM) living with HIV (MSMLWH) and increases with age. However, most previous studies of anal HPV infection and anal HSIL were performed on men under 50 years old, and relatively little is known about HSIL among older MSMLWH or MSM not living with HIV (MSM-Not-LWH).

SETTING

We enrolled MSM who were aged 50+ during 2018-2022 in San Francisco, CA.

METHODS

One hundred twenty-nine MSMLWH and 109 MSM-not-LWH participated. All participants had anal HPV DNA testing (Atila Biosystems) and high-resolution anoscopy with a biopsy of visible lesions.

RESULTS

Among MSMLWH, 47% had anal HSIL, 19% had HPV-16, and 51% had other oncogenic anal HPV types (excluding HPV-16). Among MSM-not-LWH, 37% had anal HSIL, 22% had HPV-16, and 34% had other oncogenic anal HPV types. Increasing age was not statistically associated with prevalent HSIL, HPV-16, or other oncogenic HPV infections in MSMLWH or MSM-not-LWH. HPV-16 (odds ratio: 45.1, 95% confidence interval: 15.8-129); other oncogenic HPV types (odds ratio: 5.95, 95% confidence interval: 2.74-12.9) were associated with increased odds of anal HSIL, adjusted for age, income, education, and HIV status.

CONCLUSION

The prevalence of oncogenic anal HPV, anal HPV-16, and anal HSIL remains very high in older MSMLWH and MSM-not-LWH. With recent evidence showing that treating anal HSIL prevents anal cancer, MSM aged 50+ should be considered for anal cancer screening.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

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

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

[Anogenital warts-An update]

With a prevalence of around 1% in the sexually active population anogenital warts are the most frequent human papillomavirus (HPV)-related disease. In the vast majority of cases the underlying cause of the infection is due to HPV types 6 and 11. The diagnosis can usually be clinically established but in certain cases a histopathological work-up can be useful. Buschke-Lowenstein tumors represent such a scenario. The current therapeutic armamentarium for anogenital warts ranges from surgical ablative procedures up to local immunomodulatory treatment. All procedures have different advantages and disadvantages and are relatively time-consuming and sometimes also unpleasant for the patient. Anogenital warts are also a possible expression of an incomplete immunological control of HPV. Therefore, it should be emphasized that for certain affected individuals, especially immunosuppressed patients, special attention should be given to ensuring that screening investigations for HPV-associated dysplasia is carried out according to the respective valid guidelines. The primary prophylaxis by vaccination of girls and boys prior to first HPV exposure represents a very effective option to drastically reduce the prevalence of anogenital warts and other HPV-related diseases.

Anal cancer screening results from 18-to-34-year-old men who have sex with men living with HIV

Men who have sex with men living with HIV (MSM LWH) are at highest risk for human papillomavirus (HPV)-associated anal cancer. There is no consensus on the optimal screening initiation age. This study aimed to assess the prevalence and severity of anal HPV disease among MSM LWH under the age of 35, which is a currently proposed screening age threshold. Between 2014 and 2020, 1255 18-to-34-year-old MSM LWH underwent anal cytology screening. 916 were co-tested for high-risk HPV (HR-HPV). 467 underwent high-resolution anoscopy (HRA) and biopsy. Cancer registry data were queried. Predictors of abnormal cytology (ie, ≥ASCUS) and histological high-grade squamous intraepithelial lesions (HSIL) were evaluated using unadjusted logistic regression models. Median age was 28 years (range, 18-34). 19% received at least one dose of HPV vaccine. Abnormal cytology rate was 65%. HR-HPV and HPV16 prevalence were 87% and 30%. Biopsy results were benign (10%), LSIL (43%) and HSIL (47%). No cases of prevalent or incident anal cancers were detected. Findings were similar between age subgroups (18-24, 25-29 and 30-34) except for a higher prevalence of AIN 3 in the 30-34 group (19%). Abnormal cytology was significantly associated with HR-HPV infection. Histological HSIL was associated with HR-HPV infection and cytological LSIL or worse. The absence of anal cancer in a large cohort of MSM LWH under the age of 35, despite high prevalence of anal HR-HPV infection and precancer, supports an age-based anal cancer screening strategy for MSM LWH.

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.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

There was no funding source for this study.

Demonstrating a Statistically Significant Association Between Anal High-Grade Squamous Intraepithelial Lesion and Positive OncoE6 Anal Test in Men Who Have Sex With Men and Are Living With HIV

OBJECTIVES

The aim of the study is to determine whether a positive OncoE6 Anal Test result has statistically significant higher odds of being associated with high-grade squamous intraepithelial lesion (HSIL) and to calculate sensitivity and specificity of this test for predicting HSIL in adult men who have sex with men and are living with HIV (MSMLWH).

MATERIALS AND METHODS

Men living with HIV 18 years or older having ≥atypical squamous cells of undetermined significance-grade anal cytology results were eligible to enroll in this cross-sectional study. Anal samples were collected just before the high-resolution anoscopy procedure. OncoE6 Anal Test results were compared with histology, the reference standard. Sensitivity, specificity, and odds ratio were calculated using HSIL as the threshold.

RESULTS

Two hundred seventy-seven consented MSMLWH were enrolled between June 2017 and January 2022. Of these, 219 (79.1%) had biopsies obtained and histology performed; 81 of 219 participants (37%) had 1 or more biopsies with HSIL results while the remaining 138 of 219 (63%) had only low-grade squamous intraepithelial lesion or were negative for dysplasia. Anal samples from 7 participants (8.6%, 7/81) with HSIL and 3 (2.2%, 3/138) with low-grade squamous intraepithelial lesion had positive OncoE6 Anal Test results. Odds of having HSIL were 4.26 times higher among participants testing positive for HPV16/HPV18 E6 oncoprotein(s) (OR = 4.26, 95% CI = 1.07-16.95, p = .04). The OncoE6 Anal Test demonstrated excellent specificity, 97.83% (93.78-99.55), but poor sensitivity, 8.64% (3.55-17.0).

CONCLUSIONS

In this highest-risk population for anal cancer, one could combine the OncoE6 Anal Test, having excellent specificity, with the anal Pap test, having higher sensitivity. Patients found having both an abnormal anal Pap and positive OncoE6 Anal Test result could be triaged for rapid scheduling of their high-resolution anoscopy.

Primary Anal Cancer Screening Results From 381 Women With Human Immunodeficiency Virus

BACKGROUND

Women with human immunodeficiency virus (WWH) have an elevated risk for human papillomavirus (HPV)-associated anal cancer. Primary anal cancer screening results from this population could inform practice guidelines.

METHODS

In total, 381 WWH with anal cytology screening, high-risk HPV (hrHPV) testing and genital (cervical or vaginal) cotesting within 6 months were identified during 2012-2019. Those with anal cytology of atypical squamous cells of undetermined significance (ASCUS) or worse underwent high-resolution anoscopy and biopsy. Independent predictors of anal hrHPV, HPV16, and histological anal high-grade squamous intraepithelial lesions (aHSIL) were identified using adjusted logistic regression models.

RESULTS

Prevalence of anal hrHPV, HPV16, and ASCUS or worse cytology was 61%, 13%, and 68%. Histological aHSIL was detected in 42% of WWH with ASCUS or worse anal cytology. Prevalence of genital hrHPV, HPV16, and ASCUS or worse cytology was 30%, 4%, and 28%. Genital hrHPV predicted anal hrHPV (odds ratio [OR], 5.05), while genital HPV16 predicted anal HPV16 (OR, 9.52). Genital hrHPV and anal HPV16 predicted histological aHSIL (ORs, 2.78 and 10.9).

CONCLUSIONS

Anal HPV disease was highly prevalent in this primary screening cohort of WWH. While genital screening results predicted anal disease, rates of isolated anal HPV disease were substantial, supporting universal anal cancer screening for this population.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Electrocautery ablation therapy for anal intraepithelial carcinoma: A study protocol

BACKGROUND

Anal cancer is a human papillomavirus-related cancer. Screening with high-resolution anoscopy (HRA) and subsequent therapeutic intervention are increasingly recognized as the standard procedure for anal cancer. Generally, lesions suspected as being high-grade squamous intraepithelial lesions are biopsied and treated if they are grade 2 or 3 anal intraepithelial neoplasia (AIN). According to several studies, electrocautery ablation for grade 2 or 3 AIN is highly effective. However, relapse within and outside the targeted areas after the intervention is a clinical problem. In Japan, electrocautery ablation is not available at most facilities. Therefore, this study aims to investigate the efficacy and safety of electrocautery ablation.

METHODS

This single-arm, open-label, pilot intervention study will investigate the efficacy and safety of electrocautery ablative therapy using high-frequency medical devices. Patients diagnosed with grade 2 or 3 AIN will be included and will receive ablation treatment. Then, they will be followed up at 3 and 6 months after the procedure for HRA-guided sextant biopsy. To reduce the possibility of missed lesions before and after the intervention, we will perform HRA-guided sextant biopsy routinely. In this study, a sextant biopsy is defined as at least 6 biopsies in all directions, regardless of abnormal findings under HRA. The primary outcome is the recurrence rate at 6 months, and the secondary outcomes are the adverse event and recurrence rates at 3 months.

CONCLUSION

This pilot study will provide data on the effectiveness and safety of electrocautery ablation as a treatment for grade 2 or 3 AIN.

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

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

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.

Metformin use and the risk of anal intraepithelial neoplasia in type II diabetic patients

AIM

Emerging evidence has suggested that metformin may be protective against the development of human-papillomavirus-related cancers. Anal intraepithelial neoplasia (AIN) is highly associated with human papillomavirus infection and a precancerous status of anal cancer. The aim of this study was to investigate the relationship between metformin usage and the development of AIN in a large national sample.

METHODOLOGY

The IBM MarketScan dataset was used to design a nested case-control study from 2010 to 2017. Patients aged 18-65 years with type 2 diabetes mellitus (DM) were evaluated, and cases of AIN were identified. Four controls were randomly selected in the risk set of each case by using incidence density sampling. The association between metformin usage and AIN was assessed using multivariate logistic regression modelling.

RESULTS

A total of 258 patients with type 2 DM were diagnosed with AIN during the study interval, and these were matched to 1032 control patients without a diagnosis of AIN. Patients who developed AIN had 38% lower odds of prior metformin use compared to those without a history of AIN (P < 0.01) and this finding remained robust after adjusting for age, sex, human immunodeficiency virus infection and DM complications (P = 0.02). Patients with AIN had 56% lower odds of long-term metformin use compared to control patients (P = 0.01).

CONCLUSIONS

An AIN diagnosis in patients with DM is associated with 56% lower likelihood of prior metformin use. This relationship suggests that metformin could potentially play a protective role against AIN. Prospective studies in non-diabetic patients are warranted to examine these findings further.

Epidemiology of anal human papillomavirus infection and high-grade squamous intraepithelial lesions in 29 900 men according to HIV status, sexuality, and age: a collaborative pooled analysis of 64 studies

BACKGROUND

Robust age-specific estimates of anal human papillomavirus (HPV) and high-grade squamous intraepithelial lesions (HSIL) in men can inform anal cancer prevention efforts. We aimed to evaluate the age-specific prevalence of anal HPV, HSIL, and their combination, in men, stratified by HIV status and sexuality.

METHODS

We did a systematic review for studies on anal HPV infection in men and a pooled analysis of individual-level data from eligible studies across four groups: HIV-positive men who have sex with men (MSM), HIV-negative MSM, HIV-positive men who have sex with women (MSW), and HIV-negative MSW. Studies were required to inform on type-specific HPV infection (at least HPV16), detected by use of a PCR-based test from anal swabs, HIV status, sexuality (MSM, including those who have sex with men only or also with women, or MSW), and age. Authors of eligible studies with a sample size of 200 participants or more were invited to share deidentified individual-level data on the above four variables. Authors of studies including 40 or more HIV-positive MSW or 40 or more men from Africa (irrespective of HIV status and sexuality) were also invited to share these data. Pooled estimates of anal high-risk HPV (HR-HPV, including HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68), and HSIL or worse (HSIL+), were compared by use of adjusted prevalence ratios (aPRs) from generalised linear models.

FINDINGS

The systematic review identified 93 eligible studies, of which 64 contributed data on 29 900 men to the pooled analysis. Among HIV-negative MSW anal HPV16 prevalence was 1·8% (91 of 5190) and HR-HPV prevalence was 6·9% (345 of 5003); among HIV-positive MSW the prevalences were 8·7% (59 of 682) and 26·9% (179 of 666); among HIV-negative MSM they were 13·7% (1455 of 10 617) and 41·2% (3798 of 9215), and among HIV-positive MSM 28·5% (3819 of 13 411) and 74·3% (8765 of 11 803). In HIV-positive MSM, HPV16 prevalence was 5·6% (two of 36) among those age 15-18 years and 28·8% (141 of 490) among those age 23-24 years (ptrend=0·0091); prevalence was 31·7% (1057 of 3337) among those age 25-34 years and 22·8% (451 of 1979) among those age 55 and older (ptrend<0·0001). HPV16 prevalence in HIV-negative MSM was 6·7% (15 of 223) among those age 15-18 and 13·9% (166 of 1192) among those age 23-24 years (ptrend=0·0076); the prevalence plateaued thereafter (ptrend=0·72). Similar age-specific patterns were observed for HR-HPV. No significant differences for HPV16 or HR-HPV were found by age for either HIV-positive or HIV-negative MSW. HSIL+ detection ranged from 7·5% (12 of 160) to 54·5% (61 of 112) in HIV-positive MSM; after adjustment for heterogeneity, HIV was a significant predictor of HSIL+ (aPR 1·54, 95% CI 1·36-1·73), HPV16-positive HSIL+ (1·66, 1·36-2·03), and HSIL+ in HPV16-positive MSM (1·19, 1·04-1·37). Among HPV16-positive MSM, HSIL+ prevalence increased with age.

INTERPRETATION

High anal HPV prevalence among young HIV-positive and HIV-negative MSM highlights the benefits of gender-neutral HPV vaccination before sexual activity over catch-up vaccination. HIV-positive MSM are a priority for anal cancer screening research and initiatives targeting HPV16-positive HSIL+.

FUNDING

International Agency for Research on Cancer.

Evaluation of HPV-Related Biomarkers in Anal Cytological Samples from HIV-Uninfected and HIV-Infected MSM

Men who have sex with men (MSM) harbor the highest risk for anal carcinoma, mainly caused by Human Papillomavirus (HPV). The use of HPV-related biomarkers in the screening for this neoplasia is still debated. We assessed the association between high-risk (hr)HPV DNA, HPV16/18 DNA, hrHPV E6/E7 mRNA, and p16/Ki-67 with cytological abnormalities (any grade) and high-grade intraepithelial lesions (HSIL) in HIV-uninfected and HIV-infected MSM. Overall, 150 cytological samples in PreservCyt (Hologic), with a negative to HSIL report, were analyzed for hrHPV DNA, hrHPV E6/E7 mRNA, and p16/Ki-67 using the Linear Array (Roche), Aptima (Hologic), and CINtec^® PLUS (Roche) assays. In HIV-infected MSM, positivity for all the biomarkers significantly increased with the cytological grade. In both populations, the association of hrHPV E6/E7 mRNA and p16/Ki-67 positivity with HPV16 did not differ significantly compared to hrHPVs other than HPV16. In HIV-uninfected MSM, the odds of having an HSIL increased approximately six times for the p16/Ki-67 positive cases. In HIV-infected individuals, all the biomarkers showed a significant association with HSIL, except for hrHPV DNA, with the strongest association observed for p16/Ki-67. The odds of HSIL increased almost 21 times in those positive for this biomarker. Our results encourage further investigation on the use of p16/Ki-67 dual staining in anal cancer screening for HIV-uninfected and HIV-infected MSM.