title: Lymph Node Metastasis, a Unique Independent Prognostic Factor in Early Gastric Cancer.
abstract: BACKGROUND
  Lymph node metastasis (LNM) has been shown to be related to the prognosis of early gastric cancer (EGC). The choice of optimal treatment depends on an accurate pre-operative assessment of LNM status in EGC patients. However, in China, where EGC cases account for only a small part of gastric cancer (GC) cases, there are not enough data to make an accurate assessment. Therefore, this study, which involved a relatively large number of EGC patients, aimed to explore the relationship between clinicopathological characteristics and LNM in EGC.
  
  
  METHODS
  Clinicopathological data from 205 EGC patients who underwent surgical resection at Sun Yat-Sen University Cancer Center from January 2000 to December 2011 were retrospectively analyzed. Clinicopathological characteristics were assessed to identify effective predictive factors for LNM and overall survival.
  
  
  RESULTS
  LNM occurred in 52 (25.37%) EGC cases; of these cases, 18 occurred in intra-mucosal cancers (13 N1, 4 N2 and 1 N3), and 34 occurred in sub-mucosal cancers (22 N1, 7 N2 and 5 N3). Logistic regression analysis demonstrated that tumor differentiation (P=0.002), depth of tumor infiltration (P=0.004), vessel invasion (P=0.012), tumor size (P=0.020) and gender (P=0.022) were risk factors associated with LNM in EGC, listed in order of priority. The overall survival rate was 90.2%. Kaplan-Meier survival analysis showed that overall survival of EGC patients was significantly correlated with LNM (P=0.001), N staging (P<0.001) and invasion of lymphatic or blood vessels (P=0.010), but it was not correlated with tumor size, depth of tumor infiltration or tumor cell differentiation. Moreover, a multiple Cox regression analysis demonstrated that only N staging (P=0.001) could serve as an independent prognostic predictor in EGC patients.
  
  
  CONCLUSIONS
  Because LNM independently predicts the prognosis of EGC, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) and laparoscopic partial gastrectomy should be cautiously used in high-risk EGC patients. A pre-operative assessment of LNM status based on clinicopathological factors may be useful for therapy planning.
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China; Department of Gastric & pancreatic Surgery, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Bai-Wei
authors.initials: BW
authors.lastname: Zhao
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China; Department of Gastric & pancreatic Surgery, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Chen
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Jiang
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China; Department of Gastric & pancreatic Surgery, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yin-Bo
authors.initials: YB
authors.lastname: Chen
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China; Department of Gastric & pancreatic Surgery, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Zhou
authors.affiliation: Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China; Department of Gastric & pancreatic Surgery, Cancer Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yuan-Fang
authors.initials: YF
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D055815:Young Adult