title: Submucosal invasion and risk of lymph node invasion in early Barrett's cancer: potential impact of different classification systems on patient management.
abstract: BACKGROUND
  Due to the high mortality and morbidity rates of esophagectomy, endoscopic mucosal resection (EMR) is increasingly used for the curative treatment of early low risk Barrett's adenocarcinoma.
  
  
  OBJECTIVE
  This retrospective cohort study aimed to assess the prevalence of lymph node metastases (LNM) in submucosal (T1b) esophageal adenocarcinomas (EAC) in relation to the absolute depth of submucosal tumor invasion and demonstrate the efficacy of EMR for low risk (well and moderately differentiated without lymphovascular invasion) EAC with sm1 invasion (submucosal invasion ≤500 µm) according to the Paris classification.
  
  
  METHODS
  The pathology reports of patients undergoing endoscopic resection and surgery from January 1994 until December 2013 at one center were reviewed and 54 patients with submucosal invasion were included. LNM were evaluated in surgical specimens and by follow up examinations in case of EMR.
  
  
  RESULTS
  No LNM were observed in 10 patients with sm1 adenocarcinomas that underwent endoscopic resection. Three of them underwent supplementary endoscopic eradication therapy with a median follow up of 27 months for patients with sm1 tumors. In the surgical series two patients (29%) with sm1 invasion according to the pragmatic classification (subdivision of the submucosa into three equal thirds), staged as sm2-3 in the Paris classification, had LNM. The rate of LNM for surgical patients with low risk sm1 tumors was 10% according to the pragmatic classification and 0% according to Paris classification.
  
  
  CONCLUSIONS
  Different classifications of the tumor invasion depth lead to different LNM risks and treatment strategies for sm1 adenocarcinomas. Patients with low risk sm1 adenocarcinomas appear to be suitable candidates for EMR.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Fotis
authors.affiliation: Department of Pathology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Michael
authors.initials: M
authors.lastname: Doukas
authors.affiliation: Department of Surgery, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Bas Pl
authors.initials: BP
authors.lastname: Wijnhoven
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Didden
authors.affiliation: Department of Pathology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Katharina
authors.initials: K
authors.lastname: Biermann
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Marco J
authors.initials: MJ
authors.lastname: Bruno
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center, Rotterdam, the Netherlands.
authors.forename: Arjun D
authors.initials: AD
authors.lastname: Koch
keywords: Early Barrett’s cancer; Paris classification; endoscopic mucosal resection; lymph node metastases; sm1 esophageal adenocarcinoma; submucosal invasion