title: A Lymph Node Staging System for Gastric Cancer: A Hybrid Type Based on Topographic and Numeric Systems.
abstract: Although changing a lymph node staging system from an anatomically based system to a numerically based system in gastric cancer offers better prognostic performance, several problems can arise: it does not offer information on the anatomical extent of disease and cannot represent the extent of lymph node dissection. The purpose of this study was to discover an alternative lymph node staging system for gastric cancer. Data from 6025 patients who underwent gastrectomy for primary gastric cancer between January 2000 and December 2010 were reviewed. The lymph node groups were reclassified into lesser-curvature, greater-curvature, and extra-perigastric groups. Presence of any metastatic lymph node in one group was considered positive. Lymph node groups were further stratified into four (new N0-new N3) according to the number of positive lymph node groups. Survival outcomes with this new N staging were compared with those of the current TNM system. For validation, two centers in Japan (large center, n = 3443; medium center, n = 560) were invited. Even among the same pN stages, the more advanced new N stage showed worse prognosis, indicating that the anatomical extent of metastatic lymph nodes is important. The prognostic performance of the new staging system was as good as that of the current TNM system for overall advanced gastric cancer as well as lymph node-positive gastric cancer (Harrell C-index was 0.799, 0.726, and 0.703 in current TNM and 0.799, 0.727, and 0.703 in new TNM stage). Validation sets supported these outcomes. The new N staging system demonstrated prognostic performance equal to that of the current TNM system and could thus be used as an alternative.
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Choi
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.|Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea.
authors.forename: Ji Yeong
authors.initials: JY
authors.lastname: An
authors.affiliation: Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Katai
authors.affiliation: Department of Gastrointestinal Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Seto
authors.affiliation: Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Fukagawa
authors.affiliation: Department of Gastrointestinal Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Biostatistics Collaboration Unit, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyoung-Il
authors.initials: HI
authors.lastname: Kim
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Cheong
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Hyung
authors.affiliation: Department of Surgery, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University Health System, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
mesh_terms: D000368:Aged; D005260:Female; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*; D016019:Survival Analysis