Anal Squamous Cell Carcinoma In Ulcerative Colitis: Can Pouches Withstand Traditional Treatment Protocols?

BACKGROUND: Anal squamous cell carcinoma has rarely been reported in the setting of ulcerative colitis.OBJECTIVE: This study aimed to understand the prognosis of anal squamous cell carcinoma in the setting of ulcerative colitis.DESIGN: This is a retrospective review.SETTING: This study was conducted at a referral center.PATIENTS: Adult patients with both ulcerative colitis (556.9/K51.9) and anal squamous cell carcinoma (154.3/C44.520) between January 1, 2000 and August 1, 2019 were included.MAIN OUTCOMES MEASURES: The primary outcomes measured are treatment and survival of anal squamous cell carcinoma.RESULTS: Of the 13,499 patients with ulcerative colitis treated, 17 adult patients with ulcerative colitis and anal dysplasia and/or anal squamous cell carcinoma were included in the study: 6 had a diagnosis of anal squamous cell carcinoma, 8 had high-grade squamous intraepithelial lesions, and 3 had low-grade squamous intraepithelial lesions. There were 4 men (23%) and a median age of 55 years (range, 32-69) years. At diagnosis, 6 had an IPAA, of which 5 had active pouchitis, 1 had an ileorectal anastomosis with active proctitis, 1 had a Hartmann stump with disuse proctitis, 5 had pancolitis, and 4 had left-sided colitis. Of the 6 with anal squamous cell carcinoma, all received 5-fluorouracil and mitomycin C with external beam radiation therapy. Four patients had an IPAA, all of whom required intestinal diversion or pouch excision because of treatment intolerance. At a median follow-up of 60 months, 3 patients died: one at 0 months (treatment-related myocardial infarction), one at 60 months (metastatic anal squamous cell carcinoma), and one at 129 months (malignant peripheral nerve sheath tumor); the remaining patients had no residual disease.LIMITATIONS: This study was limited because of its retrospective nature and small number of patients.CONCLUSION: Anal squamous cell carcinoma in the setting of ulcerative colitis is extremely rare. In the setting of IPAA, diversion may be necessary to prevent radiation intolerance. Careful examination of the perianal region should be performed at the time of surveillance endoscopy.