title: Negative lymph-node count is associated with survival in patients with resected esophageal squamous cell carcinoma.
abstract: BACKGROUND
  The number of recovered lymph nodes (LNs) is associated with the prognosis of patients with esophageal squamous cell carcinoma (ESCC) undergoing surgical resection. A relationship between negative LN count and patient outcome has been demonstrated in gastrointestinal cancers, including colon and gastric cancers. However, little is known about the prognostic significance of negative LN counts in ESCC.
  
  
  METHODS
  In this retrospective study we examined patient survival in relation to negative LN count in 252 patients with surgically resected ESCC. Cox proportional hazards models were used to compute hazard ratios (HRs) for death, adjusted for clinical and pathological characteristics.
  
  
  RESULTS
  Negative LN count was associated with year of operation (P = .0015) and number of fields dissected (P < .0001) but not with tumor location, TNM (ie, tumor, node, metastasis) stage, N status, or histologic grade. Patients with ≥ 31 negative LNs experienced a reduction in overall mortality compared with those with 0-30 negative LNs (log-rank P = .0042; univariate HR = 0.48, 95% confidence interval 0.28-0.79, P = .0035; multivariate HR = 0.41, 95% confidence interval 0.21-0.76, P = .0039). The influence of negative LN count on overall survival was modified by the number of fields dissected (P for interaction = .033); more negative LNs were significantly associated with lower overall mortality in three-field dissection (log rank P < .0001) but not in two-field dissection (log rank P = .93).
  
  
  CONCLUSIONS
  A negative LN count was associated with improved survival in patients with curatively resected ESCC.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Baba
authors.forename: Masayuki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Hironobu
authors.initials: H
authors.lastname: Shigaki
authors.forename: Shiro
authors.initials: S
authors.lastname: Iwagami
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Ishimoto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Iwatsuki
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome