title: Should adenocarcinoma of the esophagogastric junction be classified as esophageal cancer? A comparative analysis according to the seventh AJCC TNM classification.
abstract: OBJECTIVE
  The aim of this study was to evaluate the adequacy of esophageal classification for adenocarcinoma of the esophagogastric junction (AEJ) of the seventh American Joint Committee on Cancer (AJCC) TNM classification.
  
  
  BACKGROUND
  The seventh AJCC TNM classification proposed the new classification for AEJ as a part of esophageal cancer depending on the esophagogastric junction (EGJ) involvement. However, there are still many controversies over the classification system for AEJ.
  
  
  METHODS
  A review of pathologic reports and photographic findings at Seoul National University Hospital from 2003 to 2009 identified 4524 patients with single, primary adenocarcinoma of the EGJ (n = 497) and other regions of the stomach (GC, n = 4027) who underwent an operation with curative intent. We analyzed the clinicopathologic features and postoperative prognosis of AEJ using the Siewert classification and the seventh AJCC TNM classification.
  
  
  RESULTS
  There was no Siewert type I (AEJ I) in this study. The prognosis of AEJ was similar to that of GC. There was no difference in clinicopathologic features between AEJ II and AEJ III. Even though AEJ extending into the EGJ (AEJe) showed more advanced pathologic features than AEJ not extending into the EGJ (AEJg), the prognosis of AEJe and AEJg was not significantly different when stratified by T stage. Compared with the classification of gastric cancer applied for AEJ, esophageal classification for AEJ from the seventh AJCC TNM classification showed a loss of distinctiveness at each TNM stage.
  
  
  CONCLUSIONS
  To evaluate the postoperative prognosis of AEJ within the stomach, AEJ II and AEJ III should be considered a part of gastric cancer irrespective of EGJ involvement.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yun-Suhk
authors.initials: YS
authors.lastname: Suh
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Han
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Kong
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Lee
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Woo-Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Kuhn Uk
authors.initials: KU
authors.lastname: Lee
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000145:classification / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000368:Aged; D004938:Esophageal Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D004943:Esophagogastric Junction / Q000473:pathology; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis