Anal Canal Adenocarcinoma in a Patient with Longstanding Crohn's Disease Arising From Rectal Mucosa that Migrated From a Previously Treated Rectovaginal Fistula

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.

Cancer in Anal Fistulas

Fistula-associated anal cancer in Crohn's disease (CD) can be challenging to diagnose and treat. Patients with longstanding fistulas in the setting of CD who present with a sudden change in their symptoms should undergo biopsy under anesthesia with extensive sampling, followed by staging imaging. Pelvic magnetic resonance imaging (MRI) can be helpful in identifying the extent of the disease locally. Patients often present in the later stages due to the challenges associated with diagnosing these patients. Two subtypes of this disease include squamous cell carcinoma and adenocarcinoma, and treatment depends on diagnosis. Small sample size and lack of uniform data on treatments make it difficult to say which treatment modalities are optimal, but aggressive combined therapy is likely the best approach for survival. This will include chemotherapy and radiation and often radical resection as well. Despite this, survival is poor, although more recent data suggest that outcomes are improving.

Crohn's disease-related anal fistula cancer diagnosed by examination under anesthesia: a case report

BACKGROUND

As the number of patients with inflammatory bowel disease (IBD) increases, the incidence of IBD-related colorectal cancer (CRC) is also on the rise. Crohn's disease (CD)-related CRC has been reported to have a poorer prognosis than sporadic CRC, and the early detection of CD-related CRC is difficult. Japanese patients with CD are reported to have a higher frequency of anorectal cancer than the Western population; however, methods for early diagnosis have not yet been established because of perianal pain during the examination.

CASE PRESENTATION

We report a case of CD-related anal fistula cancer that was detected early by surveillance examination under anesthesia (EUA). The patient was a 37-year-old man, diagnosed with CD at the age of 15 years and started medical treatment. However, due to poor disease control, the intestinal tract remained highly inflamed and the patient continued to have over 10 bowel movements per day. He was referred to our hospital for surgical treatment after a colonoscopy (CS), which revealed multiple active ulcers and stenoses. Since three perianal seton drainage tubes had been placed around his anus since the age of 33 years, we decided to perform an EUA to rule out cancer coexistence in the anorectal region. After a random biopsy of the rectum by CS under general anesthesia, we resected and curetted multiple perianal fistulas as much as possible and reinserted the seton drainage tubes. Pathological examination of the fistula tract revealed adenocarcinoma in one tract, indicating the coexistence of anal fistula cancer. Based on the diagnosis of multiple intestinal stenoses and anal fistula cancer due to CD, we performed hand-assisted laparoscopic total colectomy, rectal amputation, extensive perineal resection, and reconstruction using a left rectus abdominis flap.

CONCLUSION

In a long-term CD patient with anorectal lesions, we performed an EUA to diagnose the coexistence of anal fistula cancer at an early stage, and surgical resection was achieved. EUA is effective for the early detection and treatment of CD-related CRC and may contribute to an improved prognosis.

Fistula-Associated Anal Adenocarcinoma: A 20-Year Single-Center Experience

BACKGROUND

Fistula-associated anal adenocarcinoma (FAAC) is a rare consequence in patients with long-standing perianal fistulas. A paucity of data are available for this patient collective, making clinical characterization and management of this disease difficult.

OBJECTIVE

This study aimed to describe a single-center experience with FAAC patients, their clinical course, and histopathological and molecular pathological characterization.

METHODS

All patients receiving surgery for an anal fistula in 1999-2019 at a tertiary university referral hospital were included in this retrospective analysis. Patients with FAAC were eligible for histopathological analysis, including immunohistochemistry and molecular profiling.

RESULTS

This study included 1004 patients receiving surgical treatment for an anal fistula, of whom 242 had an underlying inflammatory bowel disease (IBD). Ten patients were diagnosed with a fistula-associated anal carcinoma (1.0%), and six of these patients had an FAAC (0.6%). The mean overall survival of FAAC patients was 24 ± 3 months. FAAC immunohistochemistry revealed positive staining for CK20, CDX2 and MUC2, while stainings for CK5/6 and CK7 were negative. All FAAC specimens revealed microsatellite stability. Molecular profiling detected mutations in 35 genes, with the most frequent mutations being TP53, NOTCH1, NOTCH3, ATM, PIK3R1 and SMAD4.

CONCLUSION

FAAC is rare but associated with poor clinical outcome. Tissue acquisition is crucial for early diagnosis and therapy and should be performed in long-standing, non-healing, IBD-associated fistulas in particular. The immunophenotype of FAAC seems more similar to the rectal-type mucosa than the anal glands.

Mucinous adenocarcinoma in perianal fistula in Crohn's disease: Case report and literature review

Introduction and importance

Crohn's disease (CD) is a chronic bowel disease that, due to exacerbated inflammation, can lead to complications such as the development of perianal fistulas. The development of mucinous adenocarcinoma in perianal fistulas in patients with CD is rare and, consequently, few reports exist in the literature.

Case presentation

We report the case of a 71-year-old man diagnosed 22 years ago with CD with perineal involvement, who came with complaints of intense perianal pain, a gluteal mass, and local bleeding. Tomography of his abdomen showed an expansive, heterogeneous, and solid perianal mass on the right, with interspersed necrotic/liquefied areas and possible mucinous content. The patient was referred to the surgery department for an incisional biopsy, which confirmed mucinous adenocarcinoma. The patient underwent extra levator abdominoperineal rectal resection (APR) with partial prostatectomy.

Clinical discussion

Perineal mucinous adenocarcinoma arising in a fistula associated with CD is very rare. Since the symptoms overlap, early diagnosis of malignancy is difficult. Histological analysis is the gold standard for its diagnosis. Surgical resection through APR is well-established and, despite being a complex procedure with potential complications, tends to have good results. However, the locoregional and inguinal lymph node involvement was related to a worse progression in this case.

Conclusion

The diagnostic hypothesis of mucinous adenocarcinoma should be suspected in CD patients who present long-term perineal involvement with fistulas. Biopsies and imaging exams should be performed to aid the diagnosis of the condition and thus contribute to the surgical plan.

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Mucinous adenocarcinoma in perianal fistulas from CD patients is extremely rare.

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Magnetic resonance imaging findings help in Mucinous adenocarcinoma diagnosis.

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Locoregional and inguinal lymph node involvement is related to a worse progression.

Intestinal cancer in patients with Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Although surveillance colonoscopy is recommended by several guidelines for Crohn's disease (CD), the evidence is insufficient to support the validity of this recommendation. Moreover, the efficacy of surveillance colonoscopy for anorectal cancer remains unclear. Therefore, we performed a systematic review of cancer in patients with CD before considering the proper surveillance methods.

METHODS

We conducted a systematic review and meta-analysis examining the incidence of intestinal cancer and a literature review to clarify the characteristic features of cancer in CD. We performed the systematic literature review of studies published up to May 2019.

RESULTS

Overall, 7344 patients were included in eight studies. The standardized incidence ratios (95% confidence intervals) of colorectal cancer (CRC) and small bowel cancer (SBC) were 2.08 (1.43-3.02) and 22.01 (9.10-53.25), respectively. The prevalence of CRC and SBC was 57/7344 (0.77%) and 17/7344 (0.23%), respectively, during a median follow-up of 12.55 years. Additionally, 54 studies reporting 208 anorectal cancer cases were identified. In patients with anorectal cancer, the prognosis for survival was 2.1 ± 2.3 years, and advanced cancer greater than stage T3 occurred in 46/74 patients (62.1%). Many more reports of anorectal cancer were published in Asia than in Western countries.

CONCLUSION

Although we were unable to state a recommendation for surveillance for SBC, we should perform cancer surveillance for CRC in patients with CD. However, the characteristics of cancer may differ according to geography or race. We must establish proper and effective surveillance methods that are independently suitable to detect these differences.

Anal Adenocarcinoma Can Masquerade as Chronic Anal Fistula in Asians

Purpose

Perianal adenocarcinoma arising from a chronic anorectal fistula is a rare condition for which the natural history and optimal management are not well established. For that reason, we conducted a retrospective analysis of 5 consecutive patients with a perianal adenocarcinoma arising from a chronic anorectal fistula managed at our institution from January 2014 to December 2015.

Methods

The patients were identified from a prospectively collected colorectal cancer database that included all patients managed for colorectal cancer at our institution.

Results

The median age at diagnosis was 64 years (range, 55–72 years). Magnetic resonance imaging (MRI) was the initial investigation for all patients and showed a hyperintense T2-weighted image. One patient underwent an abdominoperineal resection following neoadjuvant chemoradiotherapy and remained disease free during the 12-month follow-up. Three patients received neoadjuvant therapy with intent for surgery, but did not undergo surgery due to either worsening health or metastatic spread. One patient declined intervention. The median overall survival was 10.5 months (range, 2–19 months).

Conclusion

A high index of suspicion is required to make a clinical diagnosis of an anal adenocarcinoma arising from a chronic fistula. Histologic diagnosis must be achieved to confirm the diagnosis. Multimodal therapy with neoadjuvant chemoradiotherapy followed by abdominoperineal resection is the treatment of choice.

Fistula-associated anal carcinoma in Crohn's disease

Fistula-associated anal carcinoma in patients with Crohn's disease (CD) is a rare condition. More recently, this entity has been increasingly reported likely due to increased recognition, and the incidence may be greater than once appreciated. There remains a paucity of data regarding the incidence, diagnosis, treatment, and outcome of fistula-associated anal carcinoma. Area covered: This review evaluates the clinical features, pathology, treatment, and prognosis of fistula-associated anal carcinoma in patients with CD. A strategy for surveillance of this carcinoma is proposed by the authors based on the evidence obtained from this review. Expert commentary: Clinicians caring for patients with CD and perianal involvement need to be aware of the rare yet extremely important association of long-standing perianal disease and fistula-associated carcinoma. Only through awareness, a high level of suspicion will be diagnosed in a timely manner. This involves a thorough history, a proper, and complete anorectal examination, along with early imaging and examination under anesthesia. Through this approach, it is hoped that early diagnose can be achieved in at-risk patients and change the significant morbidity and mortality associated with this diagnosis.