Feasibility of restorative proctocolectomy in patients with ulcerative colitis-associated lower rectal cancer: A retrospective study.

Background/objective: Restorative proctocolectomy (RP) may improve quality of life in patients with ulcerative colitis (UC)-associated lower rectal cancer to a greater extent than total proctocolectomy. However, patients with UC-associated cancer often have flat mucosal lesions that make it extremely difficult to endoscopically delineate the tumor margins. Therefore, there is a potential risk of residual tumor and local recurrence after RP in patients with UC-associated lower rectal cancer. The aim of this study was to assess the feasibility of RP in patients with UC-associated cancer of the lower rectum.

Methods: We retrospectively identified nine patients who had undergone RP for UC-associated lower rectal cancer at the Niigata University Medical and Dental Hospital between January 2000 and December 2016. The incidence of flat mucosal cancer, distal margin status, and oncologic outcomes were evaluated in the nine patients.

Results: Eight (89%) of the nine patients had flat mucosal cancer in the lower rectum. The median length of the distal margin was 22 mm (range 0-55 mm). No patient developed local or distant recurrence during follow-up. One patient had a positive distal margin. This patient underwent annual pouchoscopy, but had no local recurrence and died of pancreatic cancer 81 months after RP. The remaining eight patients were alive at the final observation. Five-year and 10-year overall survival rates in the nine patients were 100% and 66.7%, respectively.

Conclusion: Patients with UC-associated lower rectal cancer often have lesions of the flat mucosal type. However, RP is feasible and not necessarily contraindicated in such patients.