title: Clinical impact of the extent of lymph node micrometastasis in undifferentiated-type early gastric cancer.
abstract: OBJECTIVE
  Lymph node (LN) metastasis is one of the most important prognostic factors for undifferentiated-type early gastric cancer (EGC). The aim of this study was to examine expansion of micrometastasis in regional LNs to clarify the importance of lymphadenectomy for undifferentiated-type EGC.
  
  
  METHODS
  Clinicopathological features of 307 patients with undifferentiated-type EGC who underwent gastrectomy with lymphadenectomy between 1997 and 2010 at the Department of Surgical Oncology, Osaka City University, were retrospectively reviewed. Micrometastasis in LNs was detected by immunohistochemistry using anticytokeratin antibody.
  
  
  RESULTS
  The incidence of LN metastasis was 1.8% in patients with mucosal (pT1a) tumors and 17.3% in those with submucosal (pT1b) tumors. Multivariate analysis revealed that lymphatic invasion and tumor depth were independently related to LN metastasis. Micrometastasis was found in 41 (13.3%) patients. Twenty-two patients with pN0 had micrometastasis in the perigastric region. Micrometastasis had spread to the area along the left gastric or common hepatic artery in 12 patients. Patients with an upgraded stage by micrometastasis had significantly worse disease-free survival.
  
  
  CONCLUSIONS
  LN micrometastasis was observed beyond the perigastric LNs and correlated with poor outcomes in patients with undifferentiated-type EGC. These data underscore the importance of adequate lymphadenectomy for patients with undifferentiated-type EGC. © 2014 S. Karger AG, Basel.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Lee
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Masaichi
authors.initials: M
authors.lastname: Ohira
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Okita
authors.forename: Mami
authors.initials: M
authors.lastname: Yoshii
authors.forename: Katsunobu
authors.initials: K
authors.lastname: Sakurai
authors.forename: Takahiro
authors.initials: T
authors.lastname: Toyokawa
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kubo
authors.forename: Kazuya
authors.initials: K
authors.lastname: Muguruma
authors.forename: Sayaka
authors.initials: S
authors.lastname: Tanaka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ohsawa
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D018572:Disease-Free Survival; D005260:Female; D005743:Gastrectomy / Q000379:methods; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D061206:Neoplasm Micrometastasis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery