title: Prognostic significance of perinodal extension in gastric cancer.
abstract: BACKGROUND
  The grouping of patients who have a poor prognosis is important in determining a treatment strategy. The aim of this study was to investigate the clinicopathologic features and prognosis in patients with perinodal extension, with a focus on the difference of survival between homogenous groups.
  
  
  METHODS
  This study included a total of 1,092 patients who underwent curative gastrectomy for gastric adenocarcinoma from 1997 to 2004 at the Department of Surgery, Yongdong Severance Hospital, Yonsei University College of Medicine.
  
  
  RESULTS
  One hundred sixty-one patients had perinodal extension. The incidence of perinodal extension was positively correlated for T and N stages. Perinodal extension was identified as an independent prognostic factor and had more influence on survival than T and N stages. Patients who had nodal metastasis without serosal exposure and who had serosal exposure without nodal metastasis were selected as homogenous groups, and there was no difference of survival between these groups. However, when the nodal metastasis group was subdivided according to the perinodal extension, perinodal extension subgroup had significant poorer prognosis than no perinodal extension subgroup.
  
  
  CONCLUSIONS
  The perinodal extension was the most important independent prognostic factor in gastric cancer, and should be included in the TNM gastric cancer staging system.
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Won Hyuk
authors.initials: WH
authors.lastname: Choi
authors.forename: Sungsoo
authors.initials: S
authors.lastname: Kim
authors.forename: Jiayun
authors.initials: J
authors.lastname: Shen
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Cheong
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Hyung
authors.forename: Yong Il
authors.initials: YI
authors.lastname: Kim
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
authors.forename: Chan Il
authors.initials: CI
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005743:Gastrectomy / Q000379:methods; D006801:Humans; D008197:Lymph Node Excision / Q000401:mortality*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D015996:Survival Rate