title: Squamous Cell Carcinoma of the Anal Transitional Zone after Ileal Pouch Surgery for Ulcerative Colitis: Systematic Review and Treatment Perspectives.
abstract: BACKGROUND
  Few cases of pouch-related cancers have been reported in ulcerative colitis (UC), and squamous cell carcinoma (SCC) is very rare.
  
  
  METHODS
  A systematic review of the literature was performed to identify all unequivocal cases of pouch-related SCC in UC patients.
  
  
  RESULTS
  Eight cases of SCC developing after ileal pouch-anal anastomosis (IPAA) have been observed since 1978. Two arose from the pouch mucosa and 6 from below. The pooled cumulative incidence of SCC is below 0.06% after IPAA. Many patients had neoplasia on the preoperative specimen, but squamous metaplasia of the pouch or anorectal mucosa may have an important role in SCC. These patients are rarely offered chemoradiation therapy and the outcome is poor. Selected patients with SCC located close to the pouch outlet can be treated with chemoradiation prior to consideration of surgery and salvage their pouch. A chemoradiation regimen is suggested to avoid pouch excision in these patients.
  
  
  CONCLUSIONS
  SCC is rare after pouch surgery but associated with extremely poor survival. Very low SCC can be managed with chemoradiation treatment, preserving the pouch and avoiding surgery, even in older patients. The role of pouch metaplasia, surveillance frequency, and treatment modalities after IPAA need further studying.
authors.affiliation: Division of Surgery and Cancer, Imperial College London, London, UK; Department of Colorectal Surgery, The Royal Marsden Hospital, London, UK.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pellino
authors.affiliation: Division of Surgery and Cancer, Imperial College London, London, UK; Department of Colorectal Surgery, The Royal Marsden Hospital, London, UK.
authors.forename: Christos
authors.initials: C
authors.lastname: Kontovounisios
authors.affiliation: Radiotherapy Department, The Royal Marsden Hospital, London, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Tait
authors.affiliation: Division of Surgery and Cancer, Imperial College London, London, UK.
authors.forename: John
authors.initials: J
authors.lastname: Nicholls
authors.affiliation: Division of Surgery and Cancer, Imperial College London, London, UK; Department of Colorectal Surgery, The Royal Marsden Hospital, London, UK.
authors.forename: Paris P
authors.initials: PP
authors.lastname: Tekkis
keywords: Pouch; Squamous cell carcinoma; Ulcerative colitis