The importance of anal cancer screening and high-resolution anoscopy to gastroenterology practice

Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

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.

Screening of Anal HPV Precancerous Lesions: A Review after Last Recommendations

Over the last decades, the incidence of anal cancer has increased worldwide. The discovery of the HPV virus as its primary cause and the natural progression of the disease, involving precancerous lesions, have resulted in significant interest in screening for anal cancer. The use of cytology testing, high-risk HPV DNA research, high-resolution anoscopy, and their combination has been adopted with variable success in detecting anal HPV precancerous lesions. Various studies have been carried out to evaluate the sensitivity and specificity of these techniques in different populations. High-risk populations for developing anal cancer have been identified through study of incidence and prevalence. Therefore, different scientific societies and experts worldwide have provided different recommendations for screening, but a universal approach has not yet been established. The inhomogeneity of different risk groups, the variable accessibility to specifical techniques, and the lack of data regarding the cost-benefit ratio of screening are the main problems to address in order to define a consensus guideline acceptable worldwide. The purpose of this paper is to provide a comprehensive review of the literature on HPV precancerous lesions and its screening, particularly after the release of recent recommendations.

Anal dysplasia and anal cancer screening practices among liver transplant centers in the United States: Results of an online survey

BACKGROUND

Solid organ transplant recipients are at an increased risk for anogenital Human Papillomavirus (HPV)-related disease, including anal high-grade squamous intraepithelial lesions (HSIL) and anal squamous cell cancer (ASCC). Guidelines for ASCC screening in transplant recipients are limited. Our aim was to understand current practice of ASCC screening in adult liver transplant (LT) candidates and recipients at transplant centers across the United States.

METHODS

We surveyed medical directors of 113 LT centers across the United States which had publicly available contact information. The survey evaluated center perceptions on cancer and HPV disease risk in transplant populations, ASCC screening, barriers and facilitators for ASCC screening and HPV vaccination practices.

RESULTS

We received 26/113 (23%) responses, of which 24 were complete and included in the analysis. Eleven of 24 (46%) centers reported screening for ASCC and 3/24 (12.5%) centers reported having formal guidelines. Centers who perform ASCC screening were more likely to perform transplants in people living with HIV and were more aware of the burden of HPV disease in transplant populations. All respondents believed that additional data on the impact of screening on ASCC incidence would support screening decisions. Increased access to specialists for screening/high-resolution anoscopy was also perceived as a facilitator. Only 7/24 (29%) centers regularly evaluated HPV vaccination status of their patients.

CONCLUSION

This national survey of LT centers reveals non-standardized ASCC screening practices, and identified data, educational and resource needs to improve prevention of ASCC in this population.

Screening for precancerous anal lesions linked to human papillomaviruses: French recommendations for clinical practice

In France, about 2000 new cases of anal cancer are diagnosed annually. Squamous cell carcinoma is the most common histological type, mostly occurring secondary to persistent HPV16 infection. Invasive cancer is preceded by precancerous lesions. In addition to patients with a personal history of precancerous lesions and anal cancer, three groups are at very high risk of anal cancer: (i) men who have sex with men and are living with HIV, (ii) women with a history of high-grade squamous intraepithelial lesions (HSILs) or vulvar HPV cancer, and (iii) women who received a solid organ transplant more than 10 years ago. The purpose of screening is to detect HSILs so that they can be treated, thereby reducing the risk of progression to cancer. All patients with symptoms should undergo a proctological examination including standard anoscopy. For asymptomatic patients at risk, an initial HPV16 test makes it possible to target patients at risk of HSILs likely to progress to cancer. Anal cytology is a sensitive test for HSIL detection. Its sensitivity is greater than 80% and exceeds that of proctological examination with standard anoscopy. It is indicated in the event of a positive HPV16 test. In the presence of cytological abnormalities and/or lesions and a suspicion of dysplasia on clinical examination, high-resolution anoscopy is indicated. Performance is superior to that of proctological examination with standard anoscopy. However, this technique is not widely available, which limits its use. If high-resolution anoscopy is not possible, screening by a standard proctological examination is an alternative. There is a need to develop high-resolution anoscopy and triage tests and to evaluate screening strategies.

An Alternative to Cytology in Triaging Cisgender Men and Transgender Women With HIV for High-Resolution Anoscopy

OBJECTIVES

To evaluate high-risk human papillomavirus testing (hrHPV) as an alternative for anal cytology in screening for high-grade anal neoplasia (AIN2-3) among males with HIV. To identify predictive risk factors for AIN2-3 and develop a clinical tool to triage males with HIV for high-resolution anoscopy (HRA) without cytology.

DESIGN

Retrospective cohort study of 199 adult cisgender men and transgender women with HIV referred to an anal neoplasia clinic in the Southeastern United States between January 2018 and March 2021.

METHODS

Each subject underwent cytology, hrHPV, and HRA. Clinical and sociodemographic risk factors were collected for each subject. Significant risk factors for AIN2-3 were identified using logistic regression, and a triage tool incorporating these factors was developed. Screening test characteristics were calculated for cytology with and without adjunct hrHPV, hrHPV alone, and the triage tool.

RESULTS

In multivariate analysis, significant predictors of AIN2-3 were hrHPV positivity (odds ratio [OR] = 11.98, CI = 5.58-25.69) and low CD4 count (OR = 2.70, CI = 1.20-6.11). There was no significant difference in positive or negative predictive values among the tool, stand-alone hrHPV, and anal cytology with adjunct hrHPV. Sensitivity and specificity were not significantly different for stand-alone or adjunctive hrHPV testing. Compared with cytology, stand-alone hrHPV and the novel triage tool reduced unnecessary HRA referrals by 65% and 30%, respectively.

CONCLUSIONS

Stand-alone hrHPV would have missed 11 of 74 AIN2-3 and generated 74 fewer unnecessary HRAs than current cytology-based screening patterns, which led to 115 unnecessary HRAs in our cohort. We propose triaging those with low CD4 count, hrHPV positivity, and/or smoking history for HRA.

Monitoring Patients With Inflammatory Bowel Disease at High Risk of Anal Cancer

Anal cancer is a rare but deadly disease that disproportionately affects patients with inflammatory bowel disease (IBD). Rates of adenocarcinoma and human papillomavirus-related squamous cell carcinoma have been consistently demonstrated to be higher in patients with ulcerative colitis and Crohn's disease. Despite this increased risk, uniform screening, diagnosis, and treatment algorithms are lacking. This review describes the most recent literature surrounding anal cancer in the IBD population as well as the unique challenges inherent in diagnosing and treating this population. We conclude by proposing a new screening motif based off literature review and multidisciplinary clinical experience that aims to increase early detection of anal cancers in the IBD population.

Risk factors of oncogenic HPV infection in HIV-positive men with anal condyloma acuminata in Shenzhen, Southeast China: a retrospective cohort study

Background

Human immunodeficiency virus (HIV)-positive patients with anal condyloma acuminata (CA) present an increased risk of anal cancer progression associated with oncogenic human papillomavirus (HPV) infection. It is essential to explore determinants of anal infection by oncogenic HPV among HIV-positive patients with CA.

Methods

A retrospective cohort study was performed in HIV-positive patients with CA between January 2019 to October 2021 in Shenzhen, Southeast China. Exfoliated cells were collected from CA lesions and the anal canal of HPV genotypes detected by fluorescence PCR. Unconditional logistic regression analysis was used to probe associations of independent variables with oncogenic HPV infection.

Results

Among HIV-positive patients with CA, the most prevalent oncogenic genotypes were HPV52 (29.43%), HPV16 (28.93%), HPV59 (19.20%), and HPV18 (15.96%). Risk of oncogenic HPV infection increased with age at enrollment (COR: 1.04, 95% CI: 1.01-1.07, p = 0.022). In the multivariable analysis, age ≥ 35 years (AOR: 2.56, 95% CI: 1.20-5.70, p = 0.02) and history of syphilis (AOR: 3.46, 95% CI: 1.90-6.79, p < 0.01) were independent risk factors statistically associated with oncogenic HPV infection. History of syphilis (AOR: 1.72, 95% CI: 1.08-2.73, p < 0.02) was also an independent risk factor statistically associated with HPV16 or HPV18 infection.

Conclusion

In clinical practice, HIV-positive CA patients aged ≥35 years or with a history of syphilis should carry out HR-HPV testing and even anal cancer-related examinations to prevent the occurrence of anal cancer.

Prevalence and risk factors of anal human papillomavirus infection among men with anal condyloma acuminata by HIV status in ShenZhen, Southeast China: A retrospective cohort study

Patients with anal condyloma acuminatum (CA) are at risk of developing anal cancer which is associated with oncogenic human papillomavirus (HPV) infection. Investigation of anal HPV prevalence and risk factors can provide effective strategies for the prevention of anal cancer. A retrospective study was conducted among 549 patients with anal CA in the Third People's Hospital of Shenzhen between January 2019 and October 2021. HPV prevalence and HIV antibodies were detected by fluorescent PCR and ELISA, respectively. Logistic regression model and structural equation modeling (SEM) were conducted to analyzed the risk factors of oncogenic HPV infection. The overall prevalence of HPV was 96.72%. Both HPV6 (N = 285, 51.91%) and HPV11 (N = 300, 54.64%) were more than half infected and the most frequent Hr-HPV genotype was HPV16 (N = 138, 25.14%). HIV-positive (AOR: 5.02, 95% CI: 2.98-8.60, p < 0.0001) and history of syphilis (AOR: 4.24, 95% CI: 2.31-8.46, p < 0.0001) were independent risk factors statistically associated with oncogenic HPV infection. Ever had anal sex (AOR: 3.40, 95% CI: 1.28-11.81, p = 0.0267) and age 35 years and older (AOR: 2.79, 95% CI: 1.53-5.15, p = 0.0009) were associated with HPV16 and HPV52, respectively. SEM analyses showed that HIV-positive (b = 1.549, p < 0.001) and history of syphilis (b = 1.450, p < 0.001) had significant positive effects on oncogenic HPV infection. Ever had anal sex (b = 1.243, p = 0.025) and Age (b = 0.043, p = 0.002) positively drived HPV16 and HPV52 infection, respectively. Anal CA patients who are HIV-positive, have a history of syphilis, or at least 35 years old should be considered for Hr-HPV, cytology and other anal cancer related tests to reduce the risk of cancer development.

Impact of a High-Resolution Anoscopy Clinic on Management of Anal Dysplasia in Women Living With HIV

BACKGROUND

The rate of anal squamous cell cancer (aSCC) is increasing among women living with HIV. Treatment of precursor high grade squamous intraepithelial lesions (HSIL) may reduce the risk of progression to aSCC. The objective of this study was to examine effects of a dedicated high-resolution anoscopy (HRA) clinic on management of HSIL in women with HIV.

METHODS

Women living with HIV who underwent anal dysplasia screening at a single institution between 2006 and 2020 were reviewed. Those who underwent screening before (Group A) and after (Group B) the implementation of an HRA program in 2017 were compared. The primary outcome of interest was the successful detection and treatment of HSIL.

RESULTS

A total of 201 women living with HIV underwent anal dysplasia screening between 2006 and 2020. Seventy-seven patients were found to have abnormal anal cytology requiring further treatment: 43 (55.8%) in Group A and 34 (44.2%) patients in Group B. Of the patients with abnormal anal cytology, 76.7% of patients in Group A received further biopsy and treatment, whereas 79.4% of Group B patients underwent subsequent biopsy and treatment. In propensity score weighting logistic regression analysis, the Group B was 4.6 times as likely to diagnosis HSIL on biopsy compared to Group A (OR = 4.60, 95% CI: 1.15 to 18.38, P = .03).

CONCLUSIONS

Anal dysplasia is common among women living with HIV. The establishment of a HRA program was associated with increased identification and treatment of HSIL among women living with HIV, which may prevent the progression to aSCC.

Case report: a precancerous lesion associated with HPV in the anal canal diagnosed by magnifying endoscopy with narrow-band imaging and resected by endoscopic submucosal dissection

Although anal cancer remains rarely diagnosed in the world, its frequency is rising, especially in high-risk groups. The prognosis of advanced anal cancer is poor. However, there are still few reports on the endoscopic diagnosis and treatment of early anal cancer and its precancerous lesions. A 60-year-old woman was referred to our hospital for endoscopic treatment of a flat precancerous lesion in the anal canal, which was identified by narrow-band imaging (NBI) and confirmed by pathological examination in another hospital. The pathological results showed a high-grade squamous intraepithelial lesion (HSIL) in the biopsy specimen, and immunochemistry staining showed P16 positive, suggesting HPV infection. We performed pre-resection endoscopic examination for the patient. A lesion with a clear margin and tortuous dilated vessels was revealed under magnifying endoscopy with NBI (ME-NBI), which stayed unstained after iodine spraying. The lesion was successfully removed en bloc using ESD without complications, and the resected specimen was a low-grade squamous intraepithelial lesion (LSIL) with positive immunochemistry staining of P16. The patient underwent follow-up coloscopy a year after ESD, and the anal canal healed well with no suspicious lesions found. From this case, we can learn that ESD is safe and effective for curative resection of precancerous lesions of the anal canal.

Second primary malignancy risk after Hodgkin lymphoma treatment among HIV-uninfected and HIV-infected survivors

We compared secondary primary malignancy risk (SPM) in HIV-uninfected and HIV-infected Hodgkin lymphoma (HL) survivors. We used data from the California Cancer Registry on patients diagnosed with HL from 1990 to 2015 (all ages included), and standardized incidence ratios (SIRs) and multivariable competing risk models for analyses. Of 19,667 survivors, 735 were HIV-infected. Compared with the general population, the risk of SPM was increased by 2.66-fold in HIV-infected and 1.92-fold in HIV-uninfected survivors. Among HIV-infected survivors, median time to development of SPM was shorter (5.4 years) than in HIV-uninfected patients (8.1 years). Additionally, the highest risk of SPM was observed <2 years after diagnosis in HIV-infected survivors (SIR = 4.47), whereas risk was highest ≥20 years after diagnosis (SIR = 2.39) in HIV-uninfected survivors. The risk of SPMs persisted for decades and was higher among HIV-infected survivors, suggesting that these patients should benefit from long-term surveillance and cancer prevention practices.