title: Esophageal neoplasia arising from subsquamous buried glands after an apparently successful photodynamic therapy or radiofrequency ablation for Barrett's associated neoplasia.
abstract: OBJECTIVE
  Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are effective non-surgical options for the treatment of Barrett's esophagus (BE) associated neoplasia. Development of subsquamous intestinal metaplasia after successful PDT and/or RFA is a recognized phenomenon; however, the occurrence of neoplasia arising from buried glands is a rare complication.
  
  
  METHODS
  This is a prospective case series of patients treated with PDT and/or RFA from 1999 to 2014 at University College London Hospital for neoplasia associated with BE, whose outcomes were analyzed retrospectively. Prior to any ablative therapy any visible nodularity was removed with endoscopic mucosal resection (EMR). After successful PDT and/or HALO RFA treatment, defined as a complete reversal of dysplasia and metaplasia, patients underwent endoscopic follow up using the Seattle protocol.
  
  
  RESULTS
  A total of 288 patients were treated, 91 with PDT between 1999 and 2010, 173 with RFA between 2007 and 2014, and 24 with both PDT and RFA for neoplasia associated with BE. Subsquamous neoplasia occurred in seven patients (7/288, 2%). The first patient developed subsquamous invasive adenocarcinoma and underwent curative surgery. Another five patients with subsquamous neoplasia (either high-grade dysplasia or intramucosal cancer) were treated successfully with EMR. The final patient developed subsquamous invasive esophagogastric junctional adenocarcinoma with liver metastases.
  
  
  CONCLUSIONS
  Development of subsquamous neoplasia after an apparently successful PDT and/or RFA is a rare but recognized complication. Clinicians should be aware of this phenomenon and have a low threshold for performing an EMR. Thorough surveillance following successful PDT and/or RFA ensuring high-quality endoscopy is required.
authors.affiliation: Research Department of Tissue & Energy, National Medical Laser Centre, Devision of Surgery and Interventional Science, University College London , London , UK.
authors.forename: Darina
authors.initials: D
authors.lastname: Kohoutova
authors.forename: Rehan
authors.initials: R
authors.lastname: Haidry
authors.forename: Matthew
authors.initials: M
authors.lastname: Banks
authors.forename: Stephen
authors.initials: S
authors.lastname: Bown
authors.forename: Vinay
authors.initials: V
authors.lastname: Sehgal
authors.forename: Mohammed Adil
authors.initials: MA
authors.lastname: Butt
authors.forename: David
authors.initials: D
authors.lastname: Graham
authors.forename: Sally
authors.initials: S
authors.lastname: Thorpe
authors.forename: Marco
authors.initials: M
authors.lastname: Novelli
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodriguez-Justo
authors.forename: Laurence
authors.initials: L
authors.lastname: Lovat
mesh_terms: D000230:Adenocarcinoma / Q000150:complications*; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000150:complications*; D017115:Catheter Ablation; D004938:Esophageal Neoplasms / Q000150:complications*; D004945:Esophagoscopy; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000150:complications / Q000473:pathology; D008131:London; D008297:Male; D008679:Metaplasia / Q000150:complications / Q000473:pathology; D008875:Middle Aged; D010778:Photochemotherapy; D011230:Precancerous Conditions / Q000473:pathology*; D016896:Treatment Outcome
keywords: Barrett’s esophagus; photodynamic therapy; radiofrequency ablation; subsquamous neoplasia