title: Correlation between lymph node count and survival and a reappraisal of lymph node ratio as a predictor of survival in gastric cancer: A multi-institutional cohort study.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the correlation between lymph node count (LNC) and survival and to evaluate whether lymph node ratio (LNR) which is related to LNC is a better predictor of survival for gastric cancer than the N category of UICC/AJCC through a multi-institutional cohort study.
  
  
  METHODS
  The study cohort included 3284 patients from eight institutions. Lower and upper quartiles of LNC were used for comparisons. The cut-off values (0, 0.06, 0.27, and 0.49) for the LNR categories were based on Classification and Regression Trees techniques. Akaike information criteria (AIC) for Cox regression models was used to evaluate goodness of fit between competing predictor variables (LNR vs. N category).
  
  
  RESULTS
  The 5-year disease-specific survival (DSS) rates of lower and upper quartiles of LNC were 82.2% and 84.8%. In the subgroup analysis of pN category, the upper quartile of LNC showed better survival than the lower quartile in pN2, pN3a, and pN3b subgroups. Regarding LNR, 5-year DSS of LNR 0, 0-0.06, 0.06-0.27, 0.27-0.49, and >0.49 was 95.3%, 88.7%, 70.6%, 42.7%, and 17.2% respectively. Multivariate analysis showed that pT, pN, LNR, residual tumor status, distant metastasis, and tumor differentiation significantly affected survival. The analysis also confirmed superiority of LNR compared with N category in the AIC analysis.
  
  
  CONCLUSIONS
  Higher LNC correlated with better survival in patients with pN2, pN3a, and pN3b gastric cancer. Our data indicate that LNR is a better predictor of survival than N category of UICC/AJCC.
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Irwon-dong, Gangnam-gu, Seoul 135-710, South Korea. Electronic address: gsjunholee@gmail.com.
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Surgery, Chonbuk National University, Geonji-ro, Jeonju-si 561-712, South Korea. Electronic address: rao@hanmail.net.
authors.forename: J-W
authors.initials: JW
authors.lastname: Kang
authors.affiliation: Center for Clinical Trial, National Cancer Center, Biometric Research Branch, Division of Cancer Epidemiology and Prevention, Goyang, Gyeonggi-do, South Korea. Electronic address: byunghonam@ncc.re.kr.
authors.forename: B-H
authors.initials: BH
authors.lastname: Nam
authors.affiliation: Department of Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, South Korea. Electronic address: gschogs@schmc.ac.kr.
authors.forename: G S
authors.initials: GS
authors.lastname: Cho
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: wjhyung@yumc.yonsei.ac.kr.
authors.forename: W J
authors.initials: WJ
authors.lastname: Hyung
authors.affiliation: Department of Surgery, Dong-A University College of Medicine, Busan, South Korea. Electronic address: mckim@dau.ac.kr.
authors.forename: M C
authors.initials: MC
authors.lastname: Kim
authors.affiliation: Department of Surgery and Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, South Korea. Electronic address: appe98@snu.ac.kr.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Gastric Cancer Branch, National Cancer Center, Goyang, Gyeonggi-do, South Korea. Electronic address: docryu@korea.com.
authors.forename: K W
authors.initials: KW
authors.lastname: Ryu
authors.affiliation: Department of Surgery, Institute for Cancer Research, School of Medicine, Keimyung University, Daegu, South Korea. Electronic address: gsman@dsmc.or.kr.
authors.forename: S W
authors.initials: SW
authors.lastname: Ryu
authors.affiliation: Department of Surgery, Bundang Jaesaeng Hospital, Seongnam, South Korea. Electronic address: shin519@dmc.or.kr.
authors.forename: D W
authors.initials: DW
authors.lastname: Shin
authors.affiliation: Department of Surgery, Chonbuk National University, Geonji-ro, Jeonju-si 561-712, South Korea. Electronic address: happyhill@jbnu.ac.kr.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Kim
mesh_terms: D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology*; D015996:Survival Rate
keywords: Lymph nodes; Stomach neoplasm; Survival