title: Present status of photodynamic therapy for high-grade dysplasia in Barrett's esophagus.
abstract: OBJECTIVE
  Review recent developments in Barrett's dysplasia including regulatory approval of porfimer sodium photodynamic therapy.
  
  
  BACKGROUND
  Barrett's esophagus is thought to be the result of long-standing gastroesophageal reflux disease and is known to be the most important risk factor for the development of esophageal adenocarcinoma. The natural history of Barrett's esophagus is not well known, but the annual incidence of invasive adenocarcinoma is estimated to be 0.5% (reported range, 0.2%-2.0%). This represents an increased risk for esophageal cancer of 30 to 60 times higher than normal subjects. As for colorectal cancer, malignant degeneration is Barrett's esophagus is thought to occur through a continuum of histologic stages: metaplasia, dysplasia and neoplasia. Barrett's high-grade dysplasia (formerly referred to as carcinoma in situ) is the histologic stage of disease that immediately precedes the development of invasive carcinoma.
  
  
  CONCLUSIONS
  Previously, Barrett's high-grade dysplasia patients were routinely referred for esophageal resection surgery based upon the assumption of inevitable progression to cancer, the high rate of undiagnosed synchronous cancers, and few treatment alternatives. Important developments in Barrett's high-grade dysplasia include recent publications regarding the natural history of Barrett's high-grade dysplasia and the regulatory approval for endoscopic ablation therapy using porfimer sodium photodynamic therapy (Photofrin PDT).
authors.affiliation: Department of Medicine and Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA. pdt@mayo.edu
authors.forename: Herbert C
authors.initials: HC
authors.lastname: Wolfsen
mesh_terms: D001471:Barrett Esophagus / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology*; D017323:Dihematoporphyrin Ether / Q000627:therapeutic use; D006801:Humans; D008652:Mesoporphyrins / Q000627:therapeutic use; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use
chemical_list: D008652:Mesoporphyrins; D017319:Photosensitizing Agents; D017323:Dihematoporphyrin Ether; C072269:temoporfin