Pouch-related dysplasia and adenocarcinoma following restorative proctocolectomy for ulcerative colitis

Restorative proctocolectomy (RPC) is the criterion standard surgical treatment for ulcerative colitis (UC). Restorative proctocolectomy is indicated for UC that is refractory to medical treatment, for emergency conditions, and in case of neoplastic transformation. The procedure substantially reduces the risk of UC-associated dysplasia/neoplasia. However, after RPC surgery, even with mucosectomy, cancers of the pouch and/or the anal-transitional zone (ATZ) have been reported with increasing frequency since the first report in 1984. This review highlights pouch-related dysplastic and neoplastic transformation, prevalence and adverse events, risk factors and surveillance following surgery for UC.

Reports in the literature about patients undergoing pouch surgery from different institutions reported through May 2010 were reviewed to identify patients who developed these complications, and an attempt was made to develop a rational follow-up policy based on the data available.

To date, there are 43 reported cancers of the pouch or inlet after RPC for UC: 16 from retrospective series, 1 from a prospective study, and 26 in case reports. Thirty patients underwent mucosectomy and 13 had stapled anastomoses. To date, the number of 28 patients has been diagnosed with dysplasia after RPC for UC. Mucosectomy was performed in 27 of them and in 1 a stapled anastomosis was constructed without mucosectomy. In all cases reviewed, the time interval from the onset of UC to dysplasia/neoplasia was over 10 years.

Neoplastic lesions occurring in UC patients after RPC have been shown to be absolutely inevitable. Even mucosectomy does not completely eliminate the risk. There is little evidence to support routine biopsy of the ileal mucosa or the anal-transition zone except in patients with histological type C changes, sclerosing cholangitis, and unremitting pouchitis in the ileal mucosa. Such patients should be selected for endoscopic surveillance to detect dysplasia preceding pouch adenocarcinoma.