title: Inflammatory bowel disease-associated colorectal cancer: proctocolectomy and mucosectomy do not necessarily eliminate pouch-related cancer incidences.
abstract: BACKGROUND
  Colorectal cancer (CRC), the most lethal long-term complication of inflammatory bowel disease (IBD), is the culmination of a complex sequence of molecular and histologic derangements of the colon epithelium that are initiated and at least partially sustained by prolonged chronic inflammation. Dysplasia, the earliest histologic manifestation of this process, plays an important role in cancer prevention by providing the first clinical alert that this sequence is under way and by serving as an endpoint in colonoscopic surveillance of patients at high risk for CRC. Restorative proctocolectomy (RPC) is indicated for patients with IBD, specifically for ulcerative colitis that is refractory to medical treatment, emergency conditions, and/or in case of neoplastic transformation. Even after RPC with mucosectomy, pouch-related carcinomas have recently been reported with increasing frequency since the first report in 1984. We review IBD-associated CRC and pouch-related neoplasia prevalence, adverse events, risk factors, and surveillances.
  
  
  METHODS
  Literature of IBD-associated CRC patients and those undergoing RPC surgeries through 2010 were prospectively reviewed.
  
  
  RESULTS
  We found 12 studies from retrospective series and 15 case reports. To date, there are 43 reported cases of pouch-related cancers. Thirty-two patients had cancer in the anal transit zone (ATZ); of these, 28 patients had mucosectomy. Eleven patients had cancer found in the pouch body.
  
  
  CONCLUSIONS
  RPC with mucosectomy does not necessarily eliminate risks. There is little evidence to support routine surveillance of pouch mucosa and the ATZ except for patients associated with histological type C changes, sclerosing cholangitis, and unremitting pouchitis.
authors.affiliation: Department of Biochemistry and Cancer Biology, Meharry Medical College School of Medicine, 1005 Dr. D. B. Todd Jr. Blvd, Nashville, TN 37208-3599, USA. amkoma@mmc.edu
authors.forename: Amosy E
authors.initials: AE
authors.lastname: M'Koma
authors.forename: Harold L
authors.initials: HL
authors.lastname: Moses
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Adunyah
mesh_terms: D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003093:Colitis, Ulcerative / Q000150:complications / Q000235:genetics / Q000601:surgery; D039021:Colonic Pouches / Q000009:adverse effects*; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000235:genetics; D006801:Humans; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000235:genetics / Q000601:surgery*; D007413:Intestinal Mucosa / Q000601:surgery*; D011159:Population Surveillance; D016737:Proctocolectomy, Restorative / Q000009:adverse effects*; D012307:Risk Factors