title: Clinical evaluation of lymph node metastasis in gastric cancer defined by the fifth edition of the TNM classification in comparison with the Japanese system.
abstract: BACKGROUND
  This study compared the classification of lymph node metastasis according to the number of involved nodes based on the new tumour node metastasis (TNM) system (fifth edition) with the classification by the Japanese Research Society for Gastric Cancer from an anatomical perspective.
  
  
  METHODS
  The two classifications were related to long-term results in 1489 patients with gastric cancer who underwent gastrectomy with systematic extended lymphadenectomy.
  
  
  RESULTS
  Both classifications performed well as prognostic indicators (5-year survival rates: pathological (p) N0, 89 per cent; pN1, 66 per cent; pN2, 34 per cent; pN3, nil; and M1, 10 per cent by the TNM classification; n0, 89 per cent; n1, 63 per cent; n2, 46 per cent; n3, 20 per cent; and n4, 8 per cent by the Japanese classification). For regional lymph nodes, the TNM classification was a better index of the prognosis. Significant survival differences were observed among patients with M1 disease according to the number of involved lymph nodes (between one and six nodes, 48 per cent; seven to 15 nodes, 12 per cent; more than 15 nodes, 2 per cent), indicating that patients with distant metastatic lymph nodes (M1) should also be classified by the number of involved nodes. On the other hand, the Japanese classification has the added benefit of being a good indicator of the anatomical extent of lymphadenectomy.
  
  
  CONCLUSIONS
  The new TNM classification provided a better index of the prognosis of patients who underwent systematic lymph node dissection. However, both classifications have specific benefits in the surgical treatment of gastric cancer.
authors.affiliation: Department of General and Gastroenterological Surgery, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka 569-8686, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Isozaki
authors.forename: K
authors.initials: K
authors.lastname: Okajima
authors.forename: E
authors.initials: E
authors.lastname: Nomura
authors.forename: M
authors.initials: M
authors.lastname: Niki
authors.forename: S
authors.initials: S
authors.lastname: Sako
authors.forename: N
authors.initials: N
authors.lastname: Izumi
authors.forename: H
authors.initials: H
authors.lastname: Mabuchi
authors.forename: K
authors.initials: K
authors.lastname: Nishiguchi
authors.forename: N
authors.initials: N
authors.lastname: Tanigawa
mesh_terms: D005260:Female; D005743:Gastrectomy / Q000379:methods; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D011379:Prognosis; D013274:Stomach Neoplasms / Q000473:pathology*; D016019:Survival Analysis