Outcomes of surgical treatment in patients with anorectal fistula cancer

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.

A rare case of primary signet-ring adenocarcinoma of anorectal region in a young patient: Diagnostic challenges and therapeutic outcomes

Key Clinical Message

Primary signet-ring cell carcinoma of the anal canal and rectum is an extremely rare and aggressive malignancy. The present case underscores the importance of considering primary signet-ring cell carcinoma in differential diagnoses for young patients with chronic anorectal symptoms. It highlights the need for a multidisciplinary treatment approach (including surgery, chemotherapy, and radiotherapy) and comprehensive follow-up for managing this challenging condition and improving long-term patient outcomes.

Abstract

Primary signet-ring cell carcinoma of the anal canal and rectum is an exceedingly rare subtype of colorectal adenocarcinoma, often originating as an extension of rectal adenocarcinoma. This malignancy constitutes a small fraction of colorectal cancers and is scarcely reported in medical literature. We present the case of an 18-year-old male with a three-year history of progressively worsening hematochezia, anorectal pain, and defecation-associated prolapse. Initial conservative treatments failed, leading to further investigations that revealed a palpable, nodular anorectal mass. Imaging studies (including CT and MRI), and biopsy confirmed poorly differentiated adenocarcinoma with signet-ring cell morphology. The tumor exhibited extensive lymphovascular invasion and involved perirectal lymph nodes, and was staged as pT3, N2a. Immunohistochemical staining was positive for CK 7, CK 20, and SATB2, supporting the primary anorectal origin. The treatment regimen included initial diversion colostomies for symptom relief, followed by neoadjuvant chemotherapy with a modified 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) regimen and concurrent chemoradiation with Xeloda. The patient subsequently underwent an abdominoperineal resection (APR), which confirmed the diagnosis and achieved curative resection. Postoperative complications included transient ileus and wound infection, which were managed with supportive care. This case underscores the diagnostic and therapeutic challenges posed by primary signet-ring cell carcinoma of the anorectal region, highlighting the need for a high index of suspicion and comprehensive diagnostic workup in atypical presentations. The multimodal treatment approach, incorporating surgery, chemotherapy, and radiotherapy, was crucial in managing this locally advanced tumor. The rarity and aggressiveness of this carcinoma necessitate a tailored treatment strategy to improve patient outcomes. Long-term follow-up, including regular imaging and surveillance, is vital for monitoring disease recurrence and evaluating treatment effectiveness.

Chronic fistula in ano associated with adenocarcinoma: a case report with a review of the literature

The malignant transformation of chronic fistula in ano is rare, accounting for 3% to 11% of all anal canal malignancies. It results from long-standing inflammation and chronic irritation. No guidelines are available for the management of these cases. We herein present a case report of a 55-year-old man who presented with a history of constipation, perianal pain, and discharging fistula in ano of 4-year duration and underwent fistula surgery with recurrence. Biopsy of the fistulous tract revealed adenocarcinoma. He received neoadjuvant chemoradiotherapy, followed by abdominoperineal excision including excision of the fistulous tract. After 18 months of follow-up, he is free of recurrence. We present this case with a review of the literature, highlighting the management strategies.

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.

Anal fistula metastasis of rectal cancer after neoadjuvant therapy: a case report

BACKGROUND

Anal metastasis of colorectal cancer is very rare and may present synchronously or metachronously, regardless of pre-existing anal diseases. We report a case of anal fistula metastasis after completion of neoadjuvant therapy for rectal cancer, followed by surgical resection of the primary tumor and metastatic lesion.

CASE PRESENTATION

A 50-year-old man was diagnosed with rectal cancer located 5 cm from the anal verge, with a clinical stage of cT3N0M0. He denied any medical or surgical history, and physical examination revealed no perianal disease. He underwent preoperative chemoradiation therapy (CRT) consisting of a tegafur/gimeracil/oteracil potassium (S-1)-based regimen with 45 Gy of radiation. After completion of CRT, computed tomography (CT) revealed the primary tumor's partial response, but a liver mass highly suggestive of metastasis was detected. This mass was later diagnosed as cavernous hemangioma 3 months after CRT initiation. He then underwent and completed six cycles of consolidation chemotherapy with a capecitabine-based regimen. Subsequent colonoscopy revealed the complete response of the primary tumor, but CT showed thickening of the edematous rectal wall. Therefore, we planned to perform low anterior resection as a radical surgery. However, he presented with persistent anal pain after the last chemotherapy, and magnetic resonance imaging revealed a high-intensity mass behind the anus, suggestive of an anal fistula. We considered the differential diagnosis of a benign anal fistula or implantation metastasis into the anal fistula. Fistulectomy was performed, and a pathological diagnosis of tubular adenocarcinoma, suggestive of implantation metastasis, was made. Thereafter, we performed laparoscopic abdominoperineal resection. Histopathological examination revealed well-differentiated adenocarcinoma, ypT2N0, with a grade 2 therapeutic effect. Subsequent immunohistochemistry of the resected anal fistula showed a CDX-2-positive, CK20-positive, CK7-negative, and GCDFP-15 negative tumor, with implantation metastasis. There was no cancer recurrence 21 months after the radical surgery.

CONCLUSIONS

This is the first report of anal fistula metastasis after neoadjuvant therapy for rectal cancer in a patient without a previous history of anal disease. If an anal fistula is suspected during or after neoadjuvant therapy, physical and radiological assessment, differential diagnosis, and surgical intervention timing for fistula must be carefully discussed.