Anal Adenocarcinoma: A Rare Malignancy in Need of Multidisciplinary Management

Perianal Fistulizing Crohn's Disease-Associated Anorectal and Fistula Cancers: Systematic Review and Expert Consensus

BACKGROUND & AIMS

Perianal fistulizing Crohn's disease (PFCD)-associated anorectal and fistula cancers are rare but often devastating diagnoses. However, given the low incidence and consequent lack of data and clinical trials in the field, there is little to no guidance on screening and management of these cancers. To inform clinical practice, we developed consensus guidelines on PFCD-associated anorectal and fistula cancers by multidisciplinary experts from the international TOpClass consortium.

METHODS

We conducted a systematic review by standard methodology, using the Newcastle-Ottawa Scale quality assessment tool. We subsequently developed consensus statements using a Delphi consensus approach.

RESULTS

Of 561 articles identified, 110 were eligible, and 76 articles were included. The overall quality of evidence was low. The TOpClass consortium reached consensus on 6 structured statements addressing screening, risk assessment, and management of PFCD-associated anorectal and fistula cancers. Patients with long-standing (>10 years) PFCD should be considered at small but increased risk of developing perianal cancer, including squamous cell carcinoma of the anus and anorectal carcinoma. Risk factors for squamous cell carcinoma of the anus, notably human papilloma virus, should be considered. New, refractory, or progressive perianal symptoms should prompt evaluation for fistula cancer. There was no consensus on timing or frequency of screening in patients with asymptomatic perianal fistula. Multiple modalities may be required for diagnosis, including an examination under anesthesia with biopsy. Multidisciplinary team efforts were deemed central to the management of fistula cancers.

CONCLUSIONS

Inflammatory bowel disease clinicians should be aware of the risk of PFCD-associated anorectal and fistula cancers in all patients with PFCD. The TOpClass consortium consensus statements outlined herein offer guidance in managing this challenging scenario.

Anal Adenocarcinoma Treated in the Era of Total Neoadjuvant Therapy and Nonoperative Management

BACKGROUND

Anal adenocarcinoma bears a treatment strategy unique to other anal cancers.

OBJECTIVE

This study aimed to describe oncologic outcomes of total neoadjuvant therapy followed by watch-and-wait approach for anal adenocarcinoma.

DESIGN

Retrospective analysis.

SETTINGS

This study was conducted at a comprehensive cancer center.

PATIENTS

Patients with anal adenocarcinoma treated between 2004 and 2019 were selected.

INTERVENTIONS

Fifty-four patients received neoadjuvant therapy and were divided into 2 groups according to their treatment strategy: total neoadjuvant therapy versus single neoadjuvant modality therapy.

MAIN OUTCOME MEASURES

Organ preservation, tumor regrowth, local failure, distant metastasis rates, recurrence-free survival, and overall survival.

RESULTS

This study included 70 patients with anal adenocarcinoma. Fifty-four patients (77%) received neoadjuvant therapy, of whom 30 (42%) received total neoadjuvant therapy and 24 (34%) received single neoadjuvant modality. Twenty-three (33%) patients achieved complete clinical response and were managed by watch-and-wait approach. The proportion of patients able to continue to watch-and-wait approach was higher after receiving total neoadjuvant therapy (60%) compared with single neoadjuvant modality therapy (20%; p = 0.004). A tumor regrowth rate of 22% was observed in the total neoadjuvant therapy group. The 5-year overall survival rate was 70% (95% CI, 59%-83%), including 61% (95% CI, 42%-88%) for the total neoadjuvant therapy and 65% (95% CI, 48%-88%) for the single neoadjuvant modality groups. Colostomy was avoided in 50% of patients who received total neoadjuvant therapy and 83% of watch-and-wait patients. Five-year recurrence-free survival rates of 55% (95% CI, 39%-79%) and 30% (95% CI, 15%-58%) were observed in the total neoadjuvant therapy and single neoadjuvant modality groups.

LIMITATIONS

Retrospective nature.

CONCLUSIONS

This is the first report in the literature describing the safety and feasibility of nonoperative management for anal adenocarcinoma. Anal adenocarcinoma treated with total neoadjuvant therapy and nonoperative management achieve regrowth rates comparable to those observed in rectal cancer, with oncologic outcomes similar to those of traditional treatment strategies. See Video Abstract .

ADENOCARCINOMA ANAL TRATADO EN LA ERA DE LA TERAPIA NEOADYUVANTE TOTAL Y EL TRATAMIENTO NO QUIRRGICO

ANTECEDENTES:El adenocarcinoma anal conlleva una estrategia de tratamiento único para otros cánceres anales.OBJETIVO:Describir los resultados oncológicos de la terapia neoadyuvante total seguida de observar y esperar en adenocarcinoma anal.DISEÑO:Análisis retrospectivo.AJUSTE:Este estudio se llevó a cabo en un centro oncológico integral.PACIENTES:Se seleccionaron pacientes con adenocarcinoma anal tratados entre 2004-2019.INTERVENCIONES:Cincuenta y cuatro pacientes recibieron terapia neoadyuvante y se dividieron en dos grupos según su estrategia de tratamiento: terapia neoadyuvante total versus terapia de modalidad neoadyuvante única.PRINCIPALES MEDIDAS DE RESULTADO:Preservación de órganos, recurrencia tumoral, falla local, tasas de metástasis a distancia, libre de recurrencia y supervivencia general.RESULTADOS:El estudio incluyó a 70 pacientes con adenocarcinoma anal. Cincuenta y cuatro pacientes (77%) recibieron terapia neoadyuvante, de los cuales 30 (42%) recibieron terapia neoadyuvante total y 24 (34%) recibieron modalidad neoadyuvante única. Veintitrés (33%) pacientes presentaron una respuesta clínica completa y fueron tratados con vigilancia y espera. La proporción de pacientes capaces de continuar en observar y esperar fue mayor después de recibir terapia neoadyuvante total (60%) en comparación con la terapia de modalidad neoadyuvante única (20%) ( p = 0,004). Se observó una tasa de recurrencia tumoral del 22% en el grupo de terapia neoadyuvante total. La tasa de supervivencia general a 5 años fue del 70% (IC95% 59%-83 %), incluido el 61% (IC95% 42%-88%) para la terapia neoadyuvante total y el 65% (IC95% 48%-88%) para grupos de modalidad neoadyuvante única. Se evitó la colostomía en el 50% de los pacientes que recibieron terapia neoadyuvante total y el 83% de los pacientes en observar y esperar. Se observaron tasas de supervivencia libre de recurrencia a cinco años del 55% (IC95% 39%-79%) y del 30% (IC95% 15%-58%) en los grupos de terapia neoadyuvante total y modalidad neoadyuvante única, respectivamente.LIMITACIONES:Diseño retrospectivo.CONCLUSIONES:Este es el primer informe en la literatura que describe la seguridad y viabilidad del tratamiento no quirúrgico del adenocarcinoma anal. El adenocarcinoma anal tratado con terapia neoadyuvante total y manejo no quirúrgico logra tasas de recurrencia comparables a las observadas en el cáncer de recto, con resultados oncológicos similares a las estrategias de tratamientos tradicionales. (Traducción-Dr. Fidel Ruiz Healy ).

Management and staging of anal adenocarcinoma in the United States: a population-based analysis

BACKGROUND

Anal adenocarcinoma is rare with no standardized treatment regimen or staging system. Therefore, different combinations of chemotherapy, radiation, and surgery are used in management. Within the staging system, tumor stage can be based on the depth of invasion, as for rectal adenocarcinoma, or size, as in anal squamous cell carcinoma. This study aimed to analyze patterns of care and clinically available staging systems for anal adenocarcinoma using a national database.

METHODS

Adults diagnosed with anal adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results database (2004-2019). In addition, 6 different treatment regimens were identified. Stages were categorized according to the American Joint Committee on Cancer classifications of rectal adenocarcinoma and anal squamous cell carcinoma.

RESULTS

Of 1040 patients, 48% were female, the median age was 67 years, and 18% had distant metastases. Chemoradiotherapy + abdominoperineal resection was the most common treatment regimen (22%). Moreover, 5-year overall survival (OS) and disease-specific survival (DSS) were the highest for local excision only (67% and 85%) and the lowest in the alternative group (34% and 48%). After adjustment, the treatment groups that did not include surgery were associated with worse 5-year OS. In multivariable analysis, the T stage based on depth of invasion showed incrementally lower OS for T2 and T3 anal adenocarcinomas.

CONCLUSION

Omission of surgical resection in combination with chemoradiotherapy was associated with worse OS and DSS, suggesting the relevance of surgery in anal adenocarcinoma management. Prognostically, rectal staging based on depth of invasion better discriminated between T stages, indicating that providers should consider using this system in practice.

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.

Propensity-score matched analysis of the pathologic outcomes and survival benefits of neoadjuvant therapy in stage II-III anal adenocarcinoma

BACKGROUND

Anal adenocarcinomas are a rare condition which account for less than 10% of anal cancers. The present study aimed to assess the impact of neoadjuvant therapy on the clinical and pathologic outcomes and overall survival (OS) of patients with stage II-III anal adenocarcinomas after abdominoperineal resection (APR).

METHODS

A retrospective cohort study of patients with anal adenocarcinoma in the US National Cancer Database (NCDB) (2010-2020) was conducted. Propensity-score matching was used to compare patients who received neoadjuvant therapy (neoadjuvant therapy group) to the no-neoadjuvant group. The primary outcome was 5-year OS whereas secondary outcomes included conversion to open surgery, hospital stay, surgical margins, 30-day mortality, 90-day mortality, and 30-day readmission.

RESULTS

A total of 742 patients (56% male) with a mean age of 63.6 ± 12.4 years were included. A total of 214 patients in the neoadjuvant group were matched with 107 in the no-neoadjuvant group. The mean OS was similar between the two groups (47.5 vs. 44.8 months, p = 0.253). Patients who received neoadjuvant therapy had a longer median time between diagnosis and surgery (151 vs. 54 days, p < 0.001), lower 90-day mortality (1.9% vs. 6.7%, p = 0.046), more pT0 tumors (15.7% vs. 0%), less pT3-4 tumors (28.4% vs. 36.4%, p = 0.001), less pN1-2 tumors (22.9% vs. 34.7%, p < 0.001), and less lymphovascular invasion (16.2% vs. 40%, p < 0.001) than the no-neoadjuvant group. Both groups had similar conversion rates, hospital stay, 30-day mortality, 30-day readmission, and positive surgical margins.

CONCLUSIONS

Neoadjuvant therapy before APR was associated with significant downstaging of anal adenocarcinomas and lower 90-day mortality, yet similar OS to patients who were surgically treated without neoadjuvant treatment.

Radiotherapy in the management of rare gastrointestinal cancers: A systematic review

The aim of this analysis is to assess radiotherapy's role and technical aspects in an array of rare gastrointestinal (GI) cancers for adult patients. Collection data pertaining to radiotherapy and digestive rare cancers were sourced from Medline, EMBASE, and Cochrane Library. Preoperative chemoradiotherapy improved outcomes for patients with esophageal undifferentiated carcinoma compared with esophageal salivary gland types of carcinomas. For rare gastric epithelial carcinoma, perioperative chemotherapy is the common treatment. Adjuvant chemoradiotherapy showed no benefice compared with adjuvant chemotherapy for duodenal adenocarcinoma. Small bowel sarcomas respond well to radiotherapy. By analogy to anal squamous cell carcinoma, exclusive chemoradiotherapy provided better outcomes for patients with rectal squamous cell carcinoma. For anal adenocarcinoma, neoadjuvant chemoradiotherapy, followed by radical surgery, was the most effective regimen. For pancreatic neuroendocrine tumors, chemoradiotherapy can be a suitable option as postoperative or exclusive for unresectable/borderline disease. The stereotactic body radiotherapy (SBRT) is a promising approach for hepatobiliary malignancy. Radiotherapy is a valuable option in gastrointestinal stromal tumors (GIST) for palliative intent, tyrosine kinase inhibitors (TKIs) resistant disease, and unresectable or residual disease. Involved field (IF) radiotherapy for digestive lymphoma provides good results, especially for gastric extranodal marginal zone lymphoma (MALT). In conclusion, radiotherapy is not an uncommon indication in this context. A multidisciplinary approach is needed for better management of digestive rare cancers.

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.

MRI anatomy of the rectum: key concepts important for rectal cancer staging and treatment planning

A good understanding of the MRI anatomy of the rectum and its surroundings is pivotal to ensure high-quality diagnostic evaluation and reporting of rectal cancer. With this pictorial review, we aim to provide an image-based overview of key anatomical concepts essential for treatment planning, response evaluation and post-operative assessment. These concepts include the cross-sectional anatomy of the rectal wall in relation to T-staging; differences in staging and treatment between anal and rectal cancer; landmarks used to define the upper and lower boundaries of the rectum; the anatomy of the pelvic floor and anal canal, the mesorectal fascia, peritoneum and peritoneal reflection; and guides to help discern different pelvic lymph node stations on MRI to properly stage regional and non-regional rectal lymph node metastases. Finally, this review will highlight key aspects of post-treatment anatomy, including the assessment of radiation-induced changes and the evaluation of the post-operative pelvis after different surgical resection and reconstruction techniques.

Management and Outcomes in Anal Canal Adenocarcinomas—A Systematic Review

Simple Summary

Anal canal adenocarcinomas are a rare type of bowel cancer. For this reason, it is challenging to perform large studies in order to determine the optimal treatment strategy to achieve the best outcomes. Options for treatment include radiotherapy, chemotherapy and surgery. These treatments may be combined or used alone. Outcomes are regarded as survival after diagnosis and treatment, or the recurrence of the disease. There is no universal gold standard that exists, with wide variability in practice and therefore also in outcomes between institutions. Thus, by reviewing the body of literature on the subject matter, the hope is to establish a management algorithm that may be tested and refined going forward. This is the intention of this systematic review.

Abstract

(1) Background: Anal canal adenocarcinomas constitute 1% of all gastrointestinal tract cancers. There is a current lack of consensus and NICE guidelines in the United Kingdom regarding the management of this disease. The overall objective was to perform a systematic review on the multitude of practice and subsequent outcomes in this group. (2) Methods: The MEDLINE, EMBASE, EMCARE and CINAHL databases were interrogated between 2011 to 2021. PRISMA guidelines were used to select relevant studies. The primary outcome measure was 5-year overall survival (OS). Secondary outcome measures included both local recurrences (LR) and distant metastases (DM). The Newcastle–Ottawa Scale (NOS) was used to assess the quality of studies retrieved. The study was registered on PROSPERO (338286). (3) Results: Fifteen studies were included. Overall, there were 11,967 participants who were demographically matched. There were 2090 subjects in the largest study and five subjects in the smallest study. Treatment modalities varied from neoadjuvant chemoradiotherapy (CRT), CRT and surgery (CRT + S), surgery then CRT (S + CRT) and surgery only (S). Five-year OS ranged from 30.2% to 91% across the literature. LR rates ranged from 22% to 29%; DM ranged from 6% to 60%. Study heterogeneity precluded meta-analysis. (4) Conclusions: Trimodality treatment with neoadjuvant chemoradiotherapy (CRT) followed by radical surgery of abdominoperineal excision of rectum (APER) appeared to be the most effective approach, giving the best survival outcomes according to the current data.

Rectal Cancer Metastasis to the Anal Verge: An Unusual Case Presentation and Review of the Literature

Background

Anal metastasis of colorectal adenocarcinoma is very rare, represented by only a handful of case reports in the literature. Previously, reports of metastasis to this region had occurred following a history of anorectal disease, such as anal fistulae. Antecedent trauma to the area from hemorrhoidectomy, fissures, or perineal retractor injury have also been implicated.

Case Presentation

Herein we report the case of 69-year-old man without any history of anal disease presenting with a metachronous metastasis of a colorectal-type adenocarcinoma to the anal verge. He was previously treated for T1N0 rectal adenocarcinoma at the rectosigmoid junction with a low anterior resection 5 years prior, then had a T3N0 local recurrence at the colorectal anastomosis treated with neoadjuvant chemoradiation, and eventually a Hartmann's procedure 4 years later. Subsequently, on surveillance flexible sigmoidoscopy, a new tumor was identified on the perianal skin extending from the anal verge. Histopathology demonstrated colorectal-type adenocarcinoma. Flexible endoscopy identified no other residual or recurrent disease in the colon or rectal stump. The patient was treated with wide local excision and advancement flap reconstruction.

Conclusion

Isolated metastasis to the anus is an extremely rare occurrence for colorectal adenocarcinoma. There exists little evidence to inform management. One option is to treat like a locally recurrent rectal cancer with aggressive tri-modality management consisting of chemoradiation, abdominal perineal resection, and adjuvant chemotherapy. In the absence of metastatic disease, local resection and close surveillance remain an option. As always, patient factors should guide management.

Radiology of anal and lower rectal cancers

Lower rectal and anal cancers are distinct from neoplasms involving rest of the rectum. These are relatively difficult to manage owing to important relationships with the sphincter muscles. Involvement of the latter portends a poorer prognosis and increased chance of recurrence. Lymphatic drainage of these tumours is into the systemic circulation and the exact set of lymph nodes involved depends on the precise location of the tumour. The role of imaging includes assessment of local invasion, infiltration of adjacent pelvic organs, assessment of locoregional lymphatic spread and metastasis, post-chemoradiation restaging as well as post-treatment surveillance.

Squamous rectal carcinoma: a rare malignancy, literature review and management recommendations

Squamous cell carcinoma of the rectum is a rare malignancy (0.3% of all rectal cancers), with no known risk factor. These tumours are assessed as rectal cancer using immunohistochemical and radiological tests, and certain criteria (localisation, relationship with neighbouring structures) have to be fulfilled to make the diagnosis. Some clinicians used to stage them with the anal cancer TNM (tumour–node–metastasis), whereas others used the rectal cancer TNM. When localised, the tendency nowadays is to treat those tumours like squamous anal cancers with definitive chemoradiotherapy (5-fluorouracil and mitomycin) and to skip surgery. For metastatic disease there is no clearly validated regimen and treatment should be based on recommendations of squamous anal cancers because of their common histology. Concerning follow-up after a curative approach, techniques should follow those for anal cancer as well, evaluating a delayed response.

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Rectal squamous cell carcinoma (rSCC) is a rare entity for which we have limited knowledge and no clear recommendations.

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Creation of an international registry and a biological repository could increase our understating of this rare entity.

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Definitive chemoradiotherapy (CRT) should be the gold standard treatment of local/locally-advanced rSCC.

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Clarification of clinical and pathologic response rates with CRT or radiotherapy alone and patterns of failure is important.

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Timing for tumour response assessment is paramount. Data tilt towards waiting until 6 months after definitive treatment.