title: A practical scoring system based upon ROC analysis for evaluating potential lymph nodes metastasis during gastric surgery.
abstract: OBJECTIVE
  Current preoperative N staging does not offer an accurate estimation of lymph node involvement. We establish a new scoring system for predicting N stages to guide a rational lymphadenectomy for gastric cancer.
  
  
  METHODS
  Variables correlated with N stages were selected by multivariate stepwise logistic regression analysis. Variables granted the different scores according to the odds ratio (OR). Receiver operating characteristic (ROC) analysis was used to generate scoring ranges from N0 to N3. The agreement between predicted N staging and actual pN classification was analyzed using kappa statistics.
  
  
  RESULTS
  Tumor size, depth of invasion, and histological types were selected to establish the scoring system. Scores 0-4, 5-7, 8-9, and 10-13 were postulated to predict N0-3, respectively. The predicted N stage has good agreement with the actual pN classifications. The negative predictive values for N0-3 were 87.0, 86.4, 90.4, and 90.2%; the positive predictive values were 74.7, 62.8, 57.3, and 69.6%, respectively. The accuracy is 82% for N0-1, and 83.7% for N2-3.
  
  
  CONCLUSIONS
  The new scoring system can predict the N stage of gastric cancer. With its good negative predictive value, it is possible to minimize the potential hazards of applying a more extensive lymph node dissection than necessary.
authors.affiliation: Department of Surgery, the Second Affiliated Hospital, College of Medicine, Zhejiang University, P. R. China. wuyulian@medmail.com.cn
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.forename: Junxiu
authors.initials: J
authors.lastname: Yu
authors.forename: Shunliang
authors.initials: S
authors.lastname: Gao
authors.forename: Hongwei
authors.initials: H
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011237:Predictive Value of Tests; D012372:ROC Curve; D012044:Regression Analysis; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*