title: Validity and necessity of sub-classification of N3 in the 7th UICC TNM stage of gastric cancer.
abstract: BACKGROUND
  The 7th TNM staging is the first authoritative standard for evaluation of effectiveness of treatment of gastric cancer worldwide. However, revision of pN classification within TNM needs to be discussed. In particular, the N3 sub-stage is becoming more conspicuous.
  
  
  METHODS
  Clinical data of 302 pN3M0 stage gastric cancer patients who received radical gastrectomy in Tianjin Medical University Cancer Institute and Hospital from January 2001 to May 2006 were retrospectively analyzed.
  
  
  RESULTS
  Location of tumor, depth of invasion, extranodal metastasis, gastric resection, combined organs resection, lymph node metastasis, rate of lymph node metastasis, negative lymph nodes count were important prognostic factors of pN3M0 stage gastric cancers. TNM stage was also associated with prognosis. Patients at T2N3M0 stage had a better prognosis than other sub-classification. T3N3M0 and T4aN3aM0 patients had equal prognosis which followed the T2N3M0. T4aN3bM0 and T4bN3aM0 had lower survival rate than the formers. T4bN3bM0 had worst prognosis. In multivariate analysis, TNM stage group and rate of lymph node metastasis were independent prognostic factors.
  
  
  CONCLUSIONS
  The sub-stage of N3 may be useful for more accurate prediction of prognosis; it should therefore be applied in the TNM stage system.
authors.affiliation: Cancer Prevention Center, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China. tijzhangrp@163.com
authors.forename: Fang-Xuan
authors.initials: FX
authors.lastname: Li
authors.forename: Ru-Peng
authors.initials: RP
authors.lastname: Zhang
authors.forename: Han
authors.initials: H
authors.lastname: Liang
authors.forename: Ji-Chuan
authors.initials: JC
authors.lastname: Quan
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging / Q000592:standards*; D011379:Prognosis; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate