An update on anal neoplasia

Executive Summary of the Lower Anogenital Tract Cancer Evidence Review Conference

The Centers for Disease Control and Prevention sponsored a project conducted by the American College of Obstetricians and Gynecologists to develop educational materials for clinicians on the prevention and early diagnosis of gynecologic cancers. For this final module, focusing on the cancers of the lower anogenital tract (vulva, vagina, and anus), a panel of experts in evidence assessment from the Society for Academic Specialists in General Obstetrics and Gynecology, ASCCP, and the Society of Gynecologic Oncology reviewed relevant literature and current guidelines. Panel members conducted structured literature reviews, which were then reviewed by other panel members. Representatives from stakeholder professional and patient advocacy organizations met virtually in September 2022 to review and provide comment. This article is the executive summary of the review. It covers prevention, early diagnosis, and special considerations of lower anogenital tract cancer. Knowledge gaps are summarized to provide guidance for future research.

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.

The emerging role of immunotherapy in the treatment of anal cancer

For decades, chemoradiotherapy for early-stage disease and systemic chemotherapy for advanced disease have represented the mainstay of treatment for anal cancer. Over the last few years, however, the advent of immunotherapy has opened interesting therapeutic perspectives, with the establishment of new standards of care, and the development of clinical trials that may further shape the treatment algorithm for this tumour. In this review article, we discuss the rationale behind the use of immunotherapy for anal cancer and provide an overview of the available clinical data and ongoing efforts to build on these.

Human papillomavirus 16 L1 gene methylation as a potential biomarker for predicting anal intraepithelial neoplasia in men who have sex with men (MSM)

The human papillomavirus (HPV) 16 early promoter and L1 gene methylation were quantitatively measured using pyrosequencing assay in anal cells collected from men who have sex with men (MSM) to determine potential biomarkers for HPV-related anal cancer. The methylation patterns of HPV16 genes, including the early promoter (CpG 31, 37, 43, 52, and 58) and L1 genes (CpG 5600, 5606, 5609, 5615, 7136, and 7145), were analyzed in 178 anal samples. The samples were diagnosed as normal, anal intraepithelial neoplasia (AIN) 1, AIN2, and AIN3. Low methylation levels of the early promoter (< 10%) and L1 genes (< 20%) were found in all detected normal anal cells. In comparison, medium to high methylation (≥ 20–60%) in the early promoter was found in 1.5% (1/67) and 5% (2/40) of AIN1 and AIN2-3 samples, respectively. Interestingly, slightly increased L1 gene methylation levels (≥ 20–60%), especially at the HPV16 5’L1 regions CpGs 5600 and 5609, were demonstrated in AIN2-3 specimen. Moreover, a negative correlation between high HPV16 L1 gene methylation at CpGs 5600, 5609, 5615, and 7145 and a percentual CD4 count was found in AIN3 HIV positive cases. When comparing the methylation status of AIN2-3 to that of normal/AIN1 lesions, the results indicated the potential of using HPV16 L1 gene methylation as a biomarker for HPV-related cancer screening.

Cisplatin/capecitabine with intensity-modulated radiation therapy in anal squamous cell carcinoma: a preliminary study

OBJECTIVE

Mitomycin (MMC)/5-fluoroural (5-FU) with concurrent radiation is the standard treatment of anal squamous cell carcinoma (ASCC). The aim of this study is to evaluate the efficacy and safety of cisplatin/capecitabine (XP) as an alternative with intensity-modulated radiation therapy (IMRT) in ASCC setting.

METHODS

We retrospectively screened all patients with stage I-IV ASCC from January 2010 to June 2019. The records of patients who received definitive chemoradiation with cisplatin/capecitabine (XP) and IMRT were collected and analyzed.

RESULTS

The first patient was treated with XP in 2017, so totally 11 patients were included in our study from January 2017 to June 2019. All patients have experienced clinical complete response (cCR). After a median follow-up of 30 months (range, 18-39 months), no patient had local recurrence or distant metastasis. Two-year colostomy-free survival (CFS) and two-year disease-free survival (DFS) were both 100%. The median overall survival (OS) has not reached. Grade 3 acute toxicities included leukopenia (1, 9.1%), neutropenia (2, 18.2%) and thrombocytopenia (2, 18.2%). No grade 4 acute adverse events occurred.

CONCLUSION

In our study, cisplatin/capecitabine combined with IMRT was safe in ASCC patients, with favorable efficacy as an alternative, and is expected to be explored in study with larger sample.

Anal canal squamous carcinoma

Background Anal canal carcinoma is a rare neoplasm, representing 2% of the digestive tumors, and the most common is squamous cell carcinoma, with an increasing incidence.

Objective The study aims to elucidate the pathogenesis of an increasingly prevalent disease, as well as to update treatment and prognosis.

Methods A literature search in Pubmed database, including articles from 2005 to 2015 and cross-research articles with the initial research.

Results Several studies prove the role of HPV as a major risk factor in the development of squamous cell carcinoma of anal canal, as well as a greater prevalence of this neoplasia in HIV-positive people and in those who practice receptive anal intercourse. In the last two decades chemoradiotherapy remains the treatment of choice, and abdominoperineal resection is reserved for those cases of treatment failure or recurrence. Evidence advances in order to adapt the treatment to each patient, taking into account individual prognostic factors and biological tumor characteristics.

Conclusions Squamous cell carcinoma of the anal canal is a neoplasm associated with HPV; therefore, screening and vaccination programs of male individuals, by way of prevention, should be started. Many studies are needed in order to achieve development in the treatment as well as in the evaluation of the biological characteristics of the tumor.

Hellenic society of medical oncology (HESMO) guidelines for the management of anal cancer

Despite considerable improvement in the management of anal cancer, there is a great deal of variation in the outcomes among European countries, and in particular among different hospital centres in Greece and Cyprus. The aim was to elaborate a consensus on the multidisciplinary management of anal cancer, based on European guidelines (European Society of Medical Oncologists-ESMO), considering local special characteristics of our healthcare system. Following discussion and online communication among members of an executive team, a consensus was developed. Guidelines are proposed along with algorithms of diagnosis and treatment. The importance of centralisation, care by a multidisciplinary team (MDT) and adherence to guidelines are emphasised.

Anal cancer screening in a high-risk behavior group: A local picture

Study objectives To perform anal lesion and anal cancer screening in men living with HIV/AIDS.

Methods This is a descriptive, observational, cross-sectional study. Data were obtained from the Specialized Assistance Service (SAE) in Divinópolis, Minas Gerais. A sociodemographic, epidemiological, and sexual behavior questionnaire was applied; material was collected for cytology, high-resolution anoscopy (AAR) was performed, and an acceptability questionnaire applied.

Main results Of the 50 men living with HIV/AIDS invited to participate in this study, 6% were excluded because they were illiterate, 40% refused to participate, and 54% participated in the survey. Among these, all answered the self-administered questionnaire. However, ten (37.0%) underwent proctological examination and anal cytology. Of these, two did not respond to the acceptability questionnaire. No anal lesions were identified during AAR and no biopsy was required. A 10% change in anal cytology was found.

Conclusions Through the study it was possible to construct a flow of referrals from the SAE to the UFSJ Coloproctology outpatient clinic. Moreover, the existence of internal stigmas on the part of the participants regarding the proctological examination and the lack of information about anal cancer screening are challenges to be overcome.

Risk of vulvar, vaginal and anal high-grade intraepithelial neoplasia and cancer according to cervical human papillomavirus (HPV) status: A population-based prospective cohort study

OBJECTIVES

All cervical cancers and some vulvar, vaginal and anal cancers are caused by high-risk human papillomavirus (hrHPV). However, little is known about the association between cervical HPV infection and subsequent intraepithelial neoplasia and cancer at other anogenital sites. In this prospective cohort study, we estimated the risk of vulvar, vaginal and anal intraepithelial neoplasia grade 2/3 or cancer (VIN2+, VaIN2+, AIN2+) according to cervical hrHPV status.

METHODS

Liquid-based cervical cytology samples were collected from 40,399 women screened against cervical cancer in Copenhagen, Denmark, during 2002-2005. Samples were tested for hrHPV using Hybrid Capture 2 (HC2) and genotyped using INNO-LiPA. We linked the cohort with Danish nationwide registries to identify cases of VIN2+, VaIN2+ and AIN2+ during up to 15 years of follow-up. We estimated age-adjusted hazard ratios (HRs) using Cox regression and cumulative incidences using Aalen-Johansen's estimator.

RESULTS

Women with cervical HPV16 infection had increased hazard of VIN2+ (HR = 2.6; 95% confidence interval [CI], 1.2-5.5), VaIN2+ (HR = 23.5; 95% CI, 6.8-81.6) and AIN2+ (HR = 3.7; 95% CI, 1.1-12.2) compared with HC2 negative women. Women with other hrHPV types than HPV16 also had increased hazard of VaIN2+ (HR = 7.1; 95% CI, 2.3-22.3) and a borderline statistically significantly increased risk of AIN2+ (HR = 2.2; 95% CI, 0.9-4.9) compared with HC2 negative women. The 10-year cumulative incidences of VIN2+, VaIN2+ and AIN2+ in women with cervical HPV16 were 0.3% (95% CI, 0.2%-0.7%), 0.2% (95% CI, 0.1%-0.5%) and 0.1% (95 CI, 0.0%-0.4%).

CONCLUSIONS

Cervical HPV16 infection is associated with increased risk of VIN2+, VaIN2+ and AIN2+.

Patterns of care for anal cancer in the United States - a comparison between academic and community cancer centers

Background

Management of squamous cell carcinoma of the anus (SCCA) is becoming more relevant, as its incidence increases. The purpose of this study was to investigate possible differences in patient population and care delivery for SCCA between academic and community cancer programs in the United States.

Methods

A review of available data from the American College of Surgeons Committee on Cancer National Cancer DataBase focused on gender, age, race, type of health insurance, comorbidity score, distance traveled for care, stage at diagnosis, and therapy utilization (surgery, chemotherapy, and radiation therapy) as first course of treatment (FCT). The analysis included 38,766 patients treated for SCCA. Of them, 14,422 patients received treatment at Academic Cancer Programs (ACPs), while 24,344 were treated at Community Cancer Programs (CCPs) between the years 2003 and 2013.

Results

Over the 11-year study period, ACPs had significantly more male patients, of younger age, a greater non-white race population, with more Medicaid or no insurance coverage, who traveled farther for cancer center care (p < 0.001). There was no difference between ACPs and CCPs with respect to Charlson co-morbidity score and stage of SCCA at diagnosis. For stage 0 patients, use of chemotherapy was 8% for ACPs, 9% for CCPs, and use of radiotherapy was 10% for ACPs and 14% for CCPs. The incidence of stage unknown was identical at both ACPs and CCPs (11.5%). CCPs had a greater overall utilization of radiation therapy as FCT for stage 0, I, II and IV patients (p < 0.001).

Conclusions

Our study indicates that gender, demographic and socio-economic differences exist in the patient population with SCCA accessing different cancer programs in the US. The high incidence of stage unknown patients reflects ongoing challenges in the pre-treatment phase. A significant percentage of stage 0 patients received systemic chemotherapy and/or radiotherapy, rather than surgery alone. Despite comparable stage at diagnosis and comorbidity scores between ACPs and CCPs, there appear to be variations in treatment choices, especially with the use of radiotherapy, with associated cost and toxicity risks. Further analysis and monitoring of SCCA management in the US may lead to improved compliance with NCCN guidelines.

Systemic Therapies for Advanced Squamous Cell Anal Cancer

PURPOSE OF REVIEW

We aim to summarise the available evidence on systemic therapies for advanced anal cancer.

RECENT FINDINGS

There is no universal consensus on the management of this condition and the prognosis remains poor. Nevertheless, significant progress has been recently made including completion of the first, ever-conducted, randomised trial in the first-line setting, investigation of immunotherapy in the refractory setting and use of comprehensive genomic profiling for a better molecular characterisation of this disease and the identification of novel potential targets. The combination of a platinum agent and a fluoropyrimidine is generally considered the standard first-line treatment. Other cytotoxic agents, especially docetaxel and paclitaxel, have shown activity in both the chemotherapy-naive and chemo-refractory setting and are currently being investigated in clinical trials. Finally, further to the promising results of early clinical trials, immunotherapy with checkpoint inhibitors (i.e. nivolumab and pembrolizumab) is likely to become a standard second-line treatment option.

Anal canal squamous cell cancer: are surgical alternatives to chemoradiation just as effective?

PURPOSE

The purpose of this paper is to study long-term oncologic outcomes after different treatment strategies for anal canal cancer (SCAC).

METHODS

Patients with SCAC (2004-2013) were identified from Surveillance, Epidemiology, and End Results (SEER) database. Patients undergoing radiation (RT) were compared to those undergoing local excision (LE), abdominoperineal resection (APR), and abdominoperineal resection after radiation (RT + APR). Overall survival (OS) and cancer-specific survival (CSS) data were evaluated using Kaplan-Meier and Cox regression.

RESULTS

Two thousand seven hundred and seventy-two (83.8%) patients underwent RT, 382 (11.6%) LE, 77 (2.3%) APR, 76 (2.3%) RT + APR. Median age for the four groups was 60, 57, 64, and 56 years and 32, 49.7, 53.2, and 39.5% were male, respectively, while median tumor size was 4.4, 2.6, 5.3, and 5.5 cm, respectively. Five-year OS of RT, LE, APR, and RT + APR groups was 63.7, 79.6, 25.8, and 41.8% while CSS was 79.6, 92.5, 75.6, and 58.8%, respectively, (p < 0.001). Adjusted hazard ratios for OS for LE, APR, and RT + APR with RT as reference were 1.007 (0.702-1.444), 2.311 (1.367-3.906), and 2.072 (1.016-4.228), respectively.

CONCLUSION

These data suggest that APR does not provide better outcomes in treatment of SCAC. Chemoradiation remains the gold standard treatment for majority of patients. Local excision is associated with favorable outcomes in some circumstances.

Anal Neoplasia in Inflammatory Bowel Disease: Classification Proposal, Epidemiology, Carcinogenesis, and Risk Management Perspectives

Patients with inflammatory bowel disease [IBD] may develop, similarly to individuals from general population, rare cases of human papilloma virus [HPV]-related anal canal squamous cell carcinoma [SCC] and intra-epithelial precursor lesions, as well as very rare cases of anal canal adenocarcinoma. Patients with chronic perianal Crohn's disease [CD] are at substantial risk of developing SCC or adenocarcinoma from the fistula-lining epithelium, as well as SCC or adenocarcinoma arising from chronic anorectal ulcerations or strictures. Based on this lesion stratification, we provide in this review tailored incidence estimates and we propose an IBD-specific classification of all types of anal neoplasia that may occur in patients with IBD. After reviewing putative carcinogenesis of all types of neoplasia, we conclude that HPV vaccination could reduce the incidence of HPV-related lesions, although an anal screening programme related to these lesions is not mandatory on the sole basis of IBD. By contrast, we point out that all patients with chronic perianal CD should be explored in depth, including biopsies under anaesthesia and fistula curettage when necessary, in case of any change in anal symptoms ─in particular new, increasing, unexplained pain. Finally, we conclude that there is an urgent need for elaborating and evaluating surveillance algorithms in patients with chronic perianal CD, in order to avoid cancers with late diagnosis and poor prognosis.

Anal verrucous carcinoma is not related to infection with human papillomaviruses and should be distinguished from giant condyloma (Buschke-Löwenstein tumour)

AIMS

Verrucous carcinoma (VC) is a variant of well-differentiated squamous cell carcinoma and in the anal region is regarded as synonymous with giant condyloma (Buschke-Löwenstein tumour) (BLT). Aetiology, diagnostic criteria and clinical behaviour of both lesions are controversial. Recent studies suggest that VC at other sites is not associated with human papillomaviruses (HPV). We hypothesized that anal VC is also not related to HPV, while BLT is a HPV-induced lesion.

METHODS AND RESULTS

Ten cases of VC and four cases of BLT were included. Several techniques were used for HPV detection: in-situ hybridization for HPV6, 11, 16 and 18, six different polymerase chain reaction (PCR) protocols for detection of at least 89 HPV types from alpha-, beta-, gamma- and mu-PV genera and in-situ hybridization for high-risk HPV E6/E7 mRNA; p16 immunohistochemistry and morphometric analysis were also performed. Alpha-, gamma- and mu-PVs were not found in any case of VC, while HPV6 was detected in all cases of BLT. p16 overexpression was not present in any of the lesions. Among microscopic features, only the absence of koilocytosis and enlarged spinous cells seem to be useful to distinguish VC from BLT.

CONCLUSIONS

Our results suggest that anal VC, similarly to VC at other sites, is not associated with HPV infection, and must be distinguished from BLT, which is associated with low-risk HPV. Only with well-set diagnostic criteria will it be possible to ascertain clinical behaviour and optimal treatment for both lesions.

Human Papillomavirus Laboratory Testing: the Changing Paradigm

High-risk human papillomaviruses (HPVs) cause essentially all cervical cancers, most anal and oropharyngeal cancers, and some vaginal, vulvar, and penile cancers. Improved understanding of the pathogenesis of infection and the availability of newer tests are changing the approach to screening and diagnosis. Molecular tests to detect DNA from the most common high-risk HPVs are FDA approved for use in conjunction with cytology in cervical cancer screening programs. More-specific tests that detect RNA from high-risk HPV types are now also available. The use of molecular tests as the primary screening tests is being adopted in some areas. Genotyping to identify HPV16 and -18 has a recommended role in triaging patients for colposcopy who are high-risk HPV positive but have normal cytology. There are currently no recommended screening methods for anal, vulvar, vaginal, penile, or oropharyngeal HPV infections. HPV testing has limited utility in patients at high risk for anal cancer, but p16 immunohistochemistry is recommended to clarify lesions in tissue biopsy specimens that show moderate dysplasia or precancer mimics. HPV testing is recommended for oropharyngeal squamous cell tumors as a prognostic indicator. Ongoing research will help to improve the content of future guidelines for screening and diagnostic testing.

Systematic review of guidelines for the assessment and management of high-grade anal intraepithelial neoplasia (AIN II/III)

AIM

There is ambiguity with regard to the optimal management of anal intraepithelial neoplasia (AIN) III. The aim of this review was to assess and compare international/national society guidelines currently available in the literature on the management, treatment and surveillance of AIN III. We also aimed to assess the quality of the studies used to compile the guidelines and to clarify the terminology used in histological assessment.

METHOD

An electronic search of PubMed and Embase was performed using the search terms 'anal intraepithelial neoplasia', 'AIN', 'anal cancer', 'guidelines', 'surveillance' and 'management'. Literature reviews and guidelines or practice guidelines in peer reviewed journals from 1 January 2000 to 31 December 2014 assessing the treatment, surveillance or management of patients with AIN related to human papilloma virus were included. The guidelines identified by the search were assessed for the quality of evidence behind them using the Oxford Centre for Evidence-based Medicine 2011 Levels of Evidence.

RESULTS

The database search identified 5159 articles and two further guidelines were sourced from official body guidelines. After inclusion criteria were applied, 28 full-text papers were reviewed. Twenty-five of these were excluded, leaving three guidelines for inclusion in the systematic review: those published by the Association of Coloproctology of Great Britain and Ireland, the American Society of Colon and Rectal Surgeons and the Italian Society of Colorectal Surgery. No guidelines were identified on the management of AIN III from human papilloma virus associations and societies. All three guidelines agree that a high index of clinical suspicion is essential for diagnosing AIN with a disease-specific history, physical examination, digital rectal examination and anal cytology. There is interchange of terminology from high-grade AIN (HGAIN) (which incorporates AIN II/III) and AIN III in the literature leading to confusion in therapy use. Treatment varies from immunomodulation and photodynamic therapy to targeted destruction of areas of HGAIN/AIN II/III using infrared coagulation, electrocautery, cryotherapy or surgical excision but with little consensus between the guidelines. Recommendations on surveillance strategies are similarly discordant, ranging from 6-monthly physical examination to annual anoscopy ± biopsy. Over 50% of the recommendations are based on Level 3 or Level 4 evidence and many were compiled using studies that were more than 10 years old.

CONCLUSION

Despite concordance regarding diagnosis, there is significant variation in the guidelines over recommendations on the treatment and surveillance of patients with HGAIN/AIN II/III. All three sets of guidelines are based on low level, outdated evidence originating from the 1980s and 1990s.