title: A nomogram for predicting individual survival of patients with gastric cancer who underwent radical surgery with extended lymph node dissection.
abstract: BACKGROUND
  We developed and validated a nomogram for use at a high-volume center where radical surgery with extended lymph node dissection is the standard treatment for gastric cancer.
  
  
  METHODS
  Overall, 1,614 patients were randomly divided into the test set (n = 805) and validation set (n = 809). The scoring system was calculated using a Cox proportional hazard regression model with the survival of gastric cancer as the predicted endpoint. The concordance index (c-index) was used as an accuracy measure, with bootstrapping to correct for optimistic bias. Calibration plots were constructed.
  
  
  RESULTS
  Based on a Cox model, we developed a nomogram that predicts the probability of 3- and 5-year survival from the time of surgery. The bootstrap-corrected c-indices were 0.87 and 0.84 in the test and validation sets, respectively. Survival was well predicted in both sets. The predictions of our nomogram discriminated better than the AJCC staging system (test set: c-index, 0.87 vs. 0.77; P < 0.0001; validation set: c-index, 0.84 vs. 0.79; P < 0.001).
  
  
  CONCLUSIONS
  We developed and validated a nomogram that provided a significantly accurate prediction of postoperative survival in Korean patients with gastric cancer who underwent radical gastrectomy with extended lymph node dissection.
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea, skys9615@gmail.com.
authors.forename: Kyo Young
authors.initials: KY
authors.lastname: Song
authors.forename: Yong Gyu
authors.initials: YG
authors.lastname: Park
authors.forename: Hae Myung
authors.initials: HM
authors.lastname: Jeon
authors.forename: Cho Hyun
authors.initials: CH
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000401:mortality*; D006801:Humans; D008197:Lymph Node Excision / Q000401:mortality*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D049451:Nomograms; D011379:Prognosis; D011446:Prospective Studies; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D015996:Survival Rate