title: Impact of the number of resected lymph nodes on postoperative survival of patients with node-negative oesophageal squamous cell carcinoma.
abstract: OBJECTIVE
  Research on the number of resected lymph nodes (LNs) in the cases of node-negative oesophageal squamous cell carcinoma (ESCC) is inadequate. This study was designed to analyse the prognostic impact of the number of resected LNs on node-negative ESCC.
  
  
  METHODS
  Node-negative ESCC patients (n = 666) who underwent oesophagectomy between January 1990 and December 2005 were classified into three groups according to the number of LNs resected during surgery (≤8, 9-15 and ≥16). Kaplan-Meier curves and stratified analyses according to the American Joint Committee on Cancer staging were used to compare oesophageal cancer-specific survival (CSS). Cox regression and stratified analyses were used to identify the independent prognostic factors related to postoperative survival.
  
  
  RESULTS
  CSS rates increased with the number of negative resected LNs (P < 0.01). Three- and 5-year survival rates were 67.8 and 59.8%, respectively, for patients with ≥16 resected LNs, 64.8 and 53.8%, respectively, for patients with 9-15 resected LNs and 55.3 and 43.6%, respectively, for patients with ≤8 resected LNs. Multivariate analysis showed that the number of resected nodes [P < 0.01, relative risk (RR) = 1.0, 95% confidence interval (CI) 1.0-1.0] was an independent factor for CSS among node-negative ESCC patients. Further stratified analysis revealed that the number of resected LNs was an independent factor for survival in Stage IIA ESCC patients (P < 0.01, RR = 0.9, 95% CI 0.9-1.0).
  
  
  CONCLUSIONS
  The number of resected LNs is an independent prognostic factor for the survival of node-negative ESCC patients. The minimum resection number recommended for accurate staging is 16.
authors.affiliation: Department of Thoracic Surgery, Cancer Center, Sun Yat-sen University, State Key Laboratory of Oncology in South China, Guangzhou, China.
authors.forename: Qianwen
authors.initials: Q
authors.lastname: Liu
authors.forename: Zihui
authors.initials: Z
authors.lastname: Tan
authors.forename: Peng
authors.initials: P
authors.lastname: Lin
authors.forename: Hao
authors.initials: H
authors.lastname: Long
authors.forename: Lanjun
authors.initials: L
authors.lastname: Zhang
authors.forename: Tiehua
authors.initials: T
authors.lastname: Rong
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Meng
authors.forename: Guowei
authors.initials: G
authors.lastname: Ma
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery*; D004938:Esophageal Neoplasms / Q000473:pathology* / Q000601:surgery*; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies
keywords: Lymph node excision; Oesophageal neoplasms; Prognosis