title: Endoscopic treatment or surgery for undifferentiated early gastric cancer?
abstract: BACKGROUND
  Although almost all (96%) the surgical cases of undifferentiated intramucosal early gastric cancer (EGC) have been found not to have lymph node metastasis (LNM), local treatment by endoscopic mucosal resection (EMR) is not accepted as an alternative treatment to surgery for this type of EGC. If a subgroup of patients with undifferentiated EGC with negligible risk of LNM can be defined, unnecessary surgery can be avoided. This study was conducted to determine this subgroup among undifferentiated EGC patients in whom the risk of LNM can be highly ruled out in an attempt to identify candidates who can be treated by EMR.
  
  
  METHODS
  Data from 175 patients surgically resected for undifferentiated EGC were retrospectively collected, and clinicopathological factors were multivariately analyzed to identify predictive factors for LNM.
  
  
  RESULTS
  Multivariate logistic regression analysis identified two independent risk factors for LNM, namely, a large tumor (>/=20 mm, P = 0.011) and presence of lymphatic involvement (P = 0.0005). Using these two risk factors as the predictive factors, LNM was observed in 5.8% of patients who had neither of the two predictive factors, whereas 23.1% or 13.1% of patients with one or two predictive factors had LNM, respectively. In contrast, the LNM rate was calculated to be 60% in patients who had both factors. Lymph node metastasis was not found in any of 6 patients with small intramucosal lesions (<10 mm) without lymphatic involvement.
  
  
  CONCLUSIONS
  An intramucosal undifferentiated EGC that is smaller than 10 mm without lymphatic involvement can safely be treated by EMR alone, given the negligible possibility of LNM. When histological examination of endoscopically resected specimens shows lymphatic involvement or unexpectedly larger tumor size than that determined at pre-EMR endoscopic diagnosis, an additional surgical procedure should be considered.
authors.affiliation: Department of Surgery, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka City, Tokyo 181-8611, Japan. abenbtg@kyorin-u.ac.jp
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Abe
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Masanori
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Osamu
authors.initials: O
authors.lastname: Yanagida
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Masaki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Mori
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Atomi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005743:Gastrectomy; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D006801:Humans; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy*