Burden of anal squamous cell carcinoma, squamous intraepithelial lesions and HPV16 infection in solid organ transplant recipients: A systematic review and meta-analysis

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.

Clinical application of endoscopic submucosal dissection for superficially invasive squamous cell carcinoma/high-grade squamous intraepithelial lesion involving the canal anal

BACKGROUND

Superficially invasive squamous cell carcinoma (SISCC) and high-grade squamous intraepithelial lesions (HSIL) involving the anal canal are rare, and their surgical management involves local excision. Endoscopic submucosal dissection (ESD) has recently emerged as a promising treatment. This study aimed to evaluate the feasibility and safety of ESD for SISCC and HSIL in the anal canal.

METHODS

All patients diagnosed with SISCC or HSIL in the anal canal who underwent ESD between November 2018 and May 2023 were included. Patient age, sex, pathology, human immunodeficiency virus (HIV) status, human papillomavirus (HPV) status, T stage, en bloc rate, and R0 resection rate were analyzed.

RESULTS

Ten patients, including two men and eight women, with a median age of 61 (51-68) years were enrolled. All patients were HIV-negative, but five (50%) were HPV-positive. Pathological examination showed tumor stage of two patients as T2, one as T0 of SISCC, and seven as Tis of HSIL. The median specimen and tumor sizes were 24 (6-65) mm and 18 (6-55) mm, respectively. The en bloc and R0 resection rates were 100% and 80%, respectively. No severe complications occurred and no recurrence was observed at the follow-up (median follow-up period, 9 (1-35) months).

CONCLUSIONS

ESD is a reliable and minimally invasive procedure that enables more individualized treatment options for specific groups. As we were limited by the length of the observation period, the long-term performance of ESD for SISCC and HSIL involving the anal canal requires further investigation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anal Intraepithelial Neoplasia and Anal Squamous Cell Carcinoma: Updates From the Last 3 Years

ABSTRACT

In the last 3 years, new and relevant information has been published on anal cancer and anal precancerous lesions epidemiology, screening, treatment, and vaccination. This information will likely change prevention and treatment strategies for these patients in the upcoming years.

Anal Cancer and Anal Intraepithelial Neoplasia Risk among Patients Treated for HPV-Related Gynecological Diseases-A Systematic Review

BACKGROUND

The most important causative agent of neoplasms in the anogenital area is the human papillomavirus (HPV). Due to the anatomical proximity of the genital and anus area and the ease with which HPV infection is transmitted, it seems that patients after the treatment of HPV-related gynecological diseases may have an increased risk of developing a second HPV-related neoplasm anal cancer. The aim of this study was to determine the risk of anal intraepithelial neoplasia (AIN) and anal cancer (AC) among patients after the treatment of HPV-related gynecological diseases.

METHODS

We conducted a comprehensive review of the available literature from multiple databases. The study was performed following Cochrane Reviewers' Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 guidelines. Moreover, we assessed the quality of each study using QUADAS-2.

RESULTS

Twenty-five studies were included in the final analysis. Patients after the treatment of HPV-related gynecological diseases have a significantly higher risk of AC (mean standardized incidence ratio (SIR) = 5.387, mean incidence risk (IR) = 0.096%, mean IR per 100,000 person-years = 10.37) and AIN (mean IR = 23.683%) compared to the population risk.

CONCLUSIONS

patients with HPV-related gynecological diseases should constitute a group for which an appropriate primary and secondary screening for AC should be introduced.

Anal Cancer: The Past, Present and Future

Anal cancer is a rare cancer that accounts for about 2% of all gastrointestinal tract malignancies. Among anal cancer, squamous cell cancer is the most common malignancy. The incidence of all stages of anal squamous cell cancer has been increasing. Human papillomavirus infection and immunosuppression are major risk factors for anal cancer. The management of anal cancer has evolved over the past several decades and continues to do so. Chemoradiation therapy remains the mainstay for treatment for most patients with early-stage disease, whereas systemic therapy is the primary treatment for patients with metastatic disease. Patients with persistent disease or recurrence following chemoradiation therapy are treated with salvage surgery. Access to novel cytotoxic combinations and immunotherapy has improved the outcomes of patients with advanced disease. This review provides an overview of advances in the management of anal cancer over the past two decades. This paper reviews the epidemiology, risk factors, pathology, diagnosis, and management of localized and advanced anal squamous cell cancer, highlights current knowledge gaps in the management of anal cancer, and discusses future directions.

Carcinogenesis and Cancer Progression in De Novo Anal Squamous Cell Carcinoma After Organ Transplantation: A Systematic Review

Our aim was to perform a comprehensive literature review on the pathogenesis of squamous anal cancerin patients after solid-organ transplant. Medical databases were consulted until June 1, 2020, for potentially relevant publications.All studies on pathogenesis of de novo anal squamous cell carcinoma in solid-organ transplant recipients were included. Two researchers independently performed study selection, quality assessment, and data extraction and analysis. Twenty-one studies were included.None ofthe selected papers had been solely focused on carcinogenesis. Most ofthe studies identified human papillomavirus infection and immunosuppression to be significantly correlated with the development of de novo anal cancer in adult solid organ transplant recipients. CD4+ T-cell depletion and inactivation oftumor suppressor pathways were mainly implicated. All solid-organ transplant recipients, especially those who were human papillomavirus positive, were shown to be at increased risk for the development of posttransplant anal cancer. Further studies are needed to determine the specific mechanisms of pathogenesis according to different solid-organ transplant populations.

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.

High-risk human papilloma virus, precancerous lesions and cancer in anal condylomas

INTRODUCTION

Anal condylomas are associated with human papillomavirus (HPV) infection and are a risk factor for anal squamous cell carcinoma (SCC).

OBJECTIVE

To conduct a meta-analysis evaluating the prevalence of anal high-risk HPV, high-grade squamous intraepithelial lesions (HSIL) and SCC in patients with condylomas. The standardized incidence ratio (SIR) and the incidence rate of anal SCC were also calculated.

METHODS

Three electronic databases were searched until April 2020. Meta-analyses were performed using random effects models.

RESULTS

Pooled prevalence estimate of high-risk HPV (HR-HPV) in anal condylomas was 40.2% (21.0-63.1) in immunocompromised and 16.4% (10.7-24.3) in nonimmunocompromised patients, with an odds ratio (OR) of 3.79 (1.51-9.52, P = 0.005) for immunocompromised patients. HR-HPV in condylomas with HSIL was 73.8% (39.1-92.5) and in non-HSIL cases was 17.7% (9.6-30.2), corresponding to an OR of 12.33 (2.97-51.21, P = 0.001) for those with HSIL. The prevalence of HSIL in condylomas was 24.0% (16.4-33.7) in immunocompromised and 11.8% (7.2-18.8) in nonimmunocompromised patients, with an OR of 2.51 (1.72-3.65, P < 0.001) for immunocompromised patients. The overall prevalence of anal SCC in anal condylomas was 0.3% (0.0-1.7). The SIR of anal SCC was 10.7 (8.5-13.5), 20.1 (14.4-28.2) in men and 7.7 (5.6-10.5) in women. The overall incidence rate of anal SCC was 6.5 per 100 000 person-years (3.6-11.7), 12.7 (9.1-17.8) in men and 4.7 (1.7-13) in women.

CONCLUSION

Patients with a history of anal condylomas have a high risk of anal SCC, especially men. The prevalence of HR-HPV and HSIL in condylomas from immunocompromised patients is high. This information can change patient follow-up and treatment.

Prevalence of anal cytological abnormalities and high-risk human papillomavirus prevalence in kidney transplant recipients: A cross-sectional study

BACKGROUND

Transplant recipients are at high-risk of anal squamous cell cancer. We aimed to estimate the prevalence of high-risk human papillomavirus (HPV) and high-grade squamous intraepithelial lesion (HSIL) and assess characteristics associated with results METHODS: We recruited kidney transplant recipients in a single-center, 2015-2018. Participants completed a clinical questionnaire and received an anal-swab sent for HPV-DNA and cytological testing RESULTS: A total of 97 (74%) of 125 recipients approached consented to participate. Participants were median 47 (IQR 40-55) years, 60% male and median 4.5 (IQR .9-13) months-since-transplant. Of 86 assessable samples, at least one HPV genotype was detected in 15 (17%) participants; 1 (1%) HPV16, 8 (9%) other high-risk HPV. Of 76 assessable cytology samples, 9 (12%) showed evidence of abnormality; 1 (1%) HSIL, 1 (1%) atypical-squamous-cells, cannot exclude HSIL. Both HSIL recipients had high-risk HPV and biopsy confirmed HSIL. High-risk HPV was detected in six (9%) recipients with normal cytology. History of sexually transmitted infection, and abnormal cervical pap smear in women, was associated with high-risk HPV and HSIL CONCLUSIONS: High-risk HPV and HSIL testing may identify kidney transplant recipients at higher risk of anal cancer. Longitudinal studies are needed to describe the natural history of anal cancer in transplant recipients.

A Novel Model for Papillomavirus-Mediated Anal Disease and Cancer Using the Mouse Papillomavirus

Up to 95% of all anal cancers are associated with infection by human papillomavirus (HPV); however, no established preclinical model exists for high-grade anal disease and cancer mediated by a natural papillomavirus infection. To establish an infection-mediated model, we infected both immunocompromised NSG and immunocompetent FVB/NJ mice with the recently discovered murine papillomavirus MmuPV1, with and without the additional cofactors of UV B radiation (UVB) and/or the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). Infections were tracked via lavages and swabs for MmuPV1 DNA, and pathology was assessed at the endpoint. Tissues were analyzed for biomarkers of viral infection and papillomavirus-mediated disease, and the localization of viral infection was investigated using biomarkers to characterize the anal microanatomical zones.

Anal cancer and precancerous lesions: a call for improvement

Anal squamous cell carcinoma is the most common type of anal cancer and is largely associated with anal human papillomavirus infection. The incidence of anal squamous cell carcinoma is increasing, and although still uncommon in the general population, a high incidence has been noted in specific population groups (eg, patients with HIV, men who have sex with men [MSM], recipients of solid organ transplants, women with genital neoplasia, and patients with systemic lupus erythematosus or inflammatory bowel disease). The higher incidence among individuals who are HIV-positive makes anal squamous cell carcinoma one of the most common non-AIDS-defining cancers among HIV-positive individuals. Anal cancer screening in high-risk groups aims to detect high-grade squamous intraepithelial lesions, which are considered anal precancerous lesions, and for which identification can provide an opportunity for prevention. A blind anal cytology is normally the first screening method, and for patients with abnormal results, this approach can be followed by an examination of the anal canal and perianal area under magnification, along with staining-a technique known as high-resolution anoscopy. Digital anorectal examination can enable early anal cancer detection. Several societies are in favour of screening for HIV-positive MSM and recipients of transplants. There are no current recommendations for screening of anal precancerous lesions via endoscopy, but in high-risk groups, a careful observation of the squamocolumnar junction should be attempted. Several treatments can be used to treat high-grade squamous intraepithelial lesions, including argon plasma coagulation or radiofrequency ablation, which are largely limited by high recurrence rates. Gastroenterologists need to be aware of anal squamous cell carcinoma and anal precancerous lesions, given that patients at high risk are frequently encountered in the gastroenterology department. We summarise simple procedures that can help in early anal squamous cell carcinoma detection.

A meta-analysis of anal cancer incidence by risk group: Toward a unified anal cancer risk scale

Certain population groups are known to have higher than average anal cancer risk, namely persons living with HIV (PLHIV), men who have sex with men (MSM), women diagnosed with human papillomavirus (HPV)-related gynecological precancerous lesions or cancer, solid organ transplant recipients (SOTRs) and patients with autoimmune diseases. Our aim was to provide robust and comparable estimates of anal cancer burden across these groups. Summary incidence rates (IRs), as cases per 100 000 person-years (py), were calculated by fixed-effects meta-analysis. IRs were 85 (95% confidence interval [CI] = 82-89) for HIV-positive MSM (n = 7 studies; 2 229 234 py), 32 (95% CI = 30-35) for non-MSM male PLHIV (n = 5; 1626 448 py) and 22 (95% CI = 19-24) for female PLHIV (n = 6; 1 472 123 py), with strong variation by age (eg, from 16.8 < 30 years to 107.5 ≥ 60 years for HIV-positive MSM). IR was 19 (95% CI = 10-36) in HIV-negative MSM (n = 2; 48 135 py). Anal cancer IRs were much higher after diagnosis of vulvar (IR = 48 [95% CI = 38-61]; n = 4; 145 147 py) than cervical (9 [95% CI = 8-12]; n = 4; 779 098 py) or vaginal (IR = 10 [95% CI = 3-30]; n = 4; 32 671) cancer, with equivalent disparity after respective precancerous lesions. IR was 13 (95% CI = 12-15) in SOTRs (n = 5; 1 946 206 py), reaching 24.5 and 49.6 for males and females >10 years after transplant. Anal cancer IRs were 10 (95% CI = 5-19), 6 (95% CI = 3-11) and 3 (95% CI = 2-4) for systemic lupus erythematosus, ulcerative colitis and Crohn's disease, respectively. In conclusion, a unifying anal cancer risk scale, based upon comprehensive meta-analysis, can improve prioritization and standardization in anal cancer prevention/research initiatives, which are in their public health infancy.

Screening strategies for the detection of anal high-grade squamous intraepithelial lesions in women living with HIV

OBJECTIVE

HIV-infected women (WLHIV) have more than 10-fold higher risk for squamous cell cancer of the anus. Experts suggest cytology-based strategies developed for cervical cancer screening may prevent anal cancer by detecting anal cytologic or histological high-grade squamous intraepithelial lesion (hHSIL) for treatment. Currently, there is no consensus on anal-hHSIL screening strategies for WLHIV.

DESIGN

Between 2014 and 2016, 276 WLHIV were recruited at 12 US AIDS Malignancy Consortium clinical trials sites to evaluate hHSIL prevalence and (test) screening strategies.

METHODS

Participants completed detailed questionnaire, underwent anal assessments including high-risk human papillomavirus (hrHPV) testing using hrHPV-Hybrid Capture 2 (HC2) and hrHPV-APTIMA, anal cytology, and concurrent high-resolution anoscopy. Screening test characteristics for predicting hHSIL validated by central review of histologic diagnosis were estimated sensitivity, specificity, positive predictive value, and false-omission rate. Paired analyses compared sensitivity and specificity for hrHPV single tests to anal cytology alone.

RESULTS

83% (229/276) of enrolled WLHIV had complete anal assessment data and were included in this analysis. Mean age was 50, 62% black and 60 (26%) had hHSIL. Anal cyotology (>atypical squamous cells of undetermined significance), hrHPV-HC2, and hrHPV-APTIMA sensitivity estimates were similarly high (83, 77, and 75%, respectively, P values > 0.2). Specificity was higher for both hrHPV-APTIMA and hrHPV-HC2 compared with anal cytology (67 vs. 50%, P < 0.001) and (61 vs. 50%, P = 0.020), respectively.

CONCLUSION

Anal hrHPV testing demonstrated similar sensitivity for anal cytology (>atypical squamous cells of undetermined significance) to predict anal hHSIL. Among tests with similar sensitivity, the specificity was significantly higher for hrHPV-APTIMA and hrHPV-HC2. Thus, anal hrHPV testing may be an important alternative strategy to anal cytology for anal hHSIL screening among WLHIV.