title: Prognostic Discrepancy of the 6th and 7th UICC N Classification for Lymph Node Staging in Gastric Cancer Patients after Curative Resection.
abstract: BACKGROUND
  The validity of N classification of the 7th edition of the American Joint Committee on Cancer/Union Internationale contre le Cancer (AJCC/UICC) tumor-node-metastasis (TNM) staging system is still under debate. The purpose of this study was to evaluate the prognostic efficacy of the 7th edition of the AJCC/UICC TNM staging system (focusing on N stage), in comparison with the 6th edition, at a single Eastern institution.
  
  
  METHODS
  We analyzed 1,435 patients with gastric cancer who underwent curative resection performed from September 1998 to August 2003 at the Memorial Jin-Pok Kim Korea Gastric Cancer Center. We analyzed the survival rate of the patients according to the AJCC/UICC 6th and 7th editions, and compared each stage, focusing on N stage.
  
  
  RESULTS
  Significant differences in the 5-year survival rates were observed between the 6th and the 7th AJCC/UICC staging system. In the 6th edition staging system, the Kaplan-Meier curves discriminated each N stage significantly. In contrast, there was no difference in terms of survival curves for N stage according to the 7th edition, especially between N1 and N2: the Kaplan-Meier plots of survival curves between N1 (77.0%) and N2 (78.1%) stages overlapped significantly (p< 0.05).
  
  
  CONCLUSIONS
  Although the 7th UICC staging system is a more detailed and sophisticated system in the T category, there was no prognostic significance between the pN1 and pN2 stages according to our data. Therefore, we suggest establishing a new UICC staging system taking into consideration the application of the N stage.
authors.affiliation: Department of Surgery, Haeundae Paik Hospital, Busan, Republic of Korea; Memorial Jin-Pok Kim Korea Gastric Cancer Center, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Oh
authors.affiliation: Department of Surgery, Haeundae Paik Hospital, Busan, Republic of Korea; Memorial Jin-Pok Kim Korea Gastric Cancer Center, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Byoung Jo
authors.initials: BJ
authors.lastname: Suh
authors.affiliation: Department of Surgery, Haeundae Paik Hospital, Busan, Republic of Korea.
authors.forename: Jong Kwon
authors.initials: JK
authors.lastname: Park
authors.affiliation: Department of Surgery, Haeundae Paik Hospital, Busan, Republic of Korea.
authors.forename: Sung Don
authors.initials: SD
authors.lastname: Oh
authors.affiliation: Department of Surgery, Korea Cancer Center Hospital, Seoul, Republic of Korea.
authors.forename: Hang Jong
authors.initials: HJ
authors.lastname: Yu
keywords: Gastric cancer; Lymph node status; TNM system