title: Prediction of risk factors for lymph node metastasis in early gastric cancer.
abstract: OBJECTIVE
  To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.
  
  
  METHODS
  A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.
  
  
  RESULTS
  The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ(2) = 122.901, P = 0.001; χ(2) = 7.14, P = 0.008; χ(2) = 79.523, P = 0.001; χ(2) = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ(2) = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN1 (P = 0.008).
  
  
  CONCLUSIONS
  The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.
authors.affiliation: Department of Radiology, Xinhua Hospital, Shanghai Jiaotong University Medical School, Shanghai 200092, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Ren
authors.forename: Rong
authors.initials: R
authors.lastname: Cai
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Ou
authors.forename: Ye-Ning
authors.initials: YN
authors.lastname: Jin
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Li
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000231:Adenocarcinoma, Papillary / Q000556:secondary / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000556:secondary / Q000601:surgery; D002454:Cell Differentiation; D016009:Chi-Square Distribution; D055088:Early Detection of Cancer; D005260:Female; D005743:Gastrectomy; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery
keywords: Gastrectomy; Gastric neoplasm; Lymph node metastasis; Lymphadenectomy; Risk factors