title: Preferred location for the development of esophageal adenocarcinoma within a segment of intestinal metaplasia.
abstract: BACKGROUND
  Barrett's metaplasia is the predominant precursor for the development of esophageal adenocarcinoma. This precancerous lesion has become the focus of various surveillance programs aimed at detecting earlier and therefore potentially curable lesions. However, sampling error by missing invasive cancer lesions is a common problem. This study aimed to identify preferred locations within a segment of Barrett's mucosa for the development of esophageal adenocarcinoma.
  
  
  METHODS
  The study group consisted of 213 patients with histologically proven esophageal adenocarcinoma. Of those, there were 134 cases of early cancer and 79 cases of locally advanced lesions. These patients received neoadjuvant chemotherapy. The frequency of intestinal metaplasia and the location of the tumor occurrence within the segment of intestinal metaplasia were assessed.
  
  
  RESULTS
  Intestinal metaplasia was found in 83% of the early lesions and in 98% of the advanced tumors after neoadjuvant chemotherapy. In 82.2% of the cases, the tumor was located at the distal margin of the intestinal metaplasia in patients with early tumor manifestations. The remaining tumor mass after neoadjuvant therapy also was located predominantly at the distal margin of the segment of intestinal metaplasia (85% of the cases).
  
  
  CONCLUSIONS
  The results demonstrate that almost all adenocarcinomas of the esophagus are based on the development of a segment of intestinal metaplasia. The distal margin of Barrett's mucosa seems to be the most vulnerable location for the development of invasive cancer.
authors.affiliation: Department of Surgery, Klinikum rechts der Isar, TU Muenchen, Ismaningerstrasse 22, 81675, Munich, Germany. theisen@nt1.chir.med.tu-muenchen.de
authors.forename: J
authors.initials: J
authors.lastname: Theisen
authors.forename: H J
authors.initials: HJ
authors.lastname: Stein
authors.forename: M
authors.initials: M
authors.lastname: Feith
authors.forename: W K H
authors.initials: WK
authors.lastname: Kauer
authors.forename: H J
authors.initials: HJ
authors.lastname: Dittler
authors.forename: D
authors.initials: D
authors.lastname: Pirchi
authors.forename: J R
authors.initials: JR
authors.lastname: Siewert
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000209:etiology*; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001706:Biopsy; D016099:Endoscopy, Gastrointestinal; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000209:etiology*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D007422:Intestines / Q000473:pathology*; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness / Q000473:pathology; D011230:Precancerous Conditions / Q000150:complications* / Q000473:pathology*