title: Number of negative lymph nodes is associated with survival in thoracic esophageal squamous cell carcinoma patients undergoing three-field lymphadenectomy.
abstract: BACKGROUND
  The number of negative lymph nodes (NLNs) can be used for predicting clinical outcomes for patients with esophageal carcinoma as it is believed to reflect the extent of lymphadenectomy. However, when patients are treated with the same surgical procedure, its prognostic value is not clear.
  
  
  METHODS
  We reviewed the records of 332 patients with thoracic esophageal squamous cell carcinoma (ESCC) who underwent three-field lymphadenectomy (3FLND) and had at least 15 lymph nodes removed. We used Kaplan-Meier estimates to compute overall survival (OS), the log-rank tests to assess the equality of survival rates, and Cox regression analyses to evaluate the association between survival and NLN count after adjusting for potential confounders.
  
  
  RESULTS
  At a median follow-up interval of 36 months, the median OS was 47 months and the 5-year survival rate was 47.0 %. NLN count was independently associated with OS, and higher numbers of NLNs were linked to better OS (hazard ratio [HR] 0.970; 95 % confidence interval [CI] 0.955-0.986); the effect did not change after we stratified patients into node-negative (HR 0.966; 95 % CI 0.933-1.000) and node-positive (HR 0.973; 95 % CI 0.955-0.991) groups.
  
  
  CONCLUSIONS
  The NLN count is an important independent prognostic factor for patients with thoracic ESCC treated with 3FLND.
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.
authors.forename: Zhengfei
authors.initials: Z
authors.lastname: Zhu
authors.forename: Haiquan
authors.initials: H
authors.lastname: Chen
authors.forename: Weiwei
authors.initials: W
authors.lastname: Yu
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Fu
authors.forename: Jiaqing
authors.initials: J
authors.lastname: Xiang
authors.forename: Hecheng
authors.initials: H
authors.lastname: Li
authors.forename: Yawei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Menghong
authors.initials: M
authors.lastname: Sun
authors.forename: Qiao
authors.initials: Q
authors.lastname: Wei
authors.forename: Weixin
authors.initials: W
authors.lastname: Zhao
authors.forename: Kuaile
authors.initials: K
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D004938:Esophageal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016629:Esophagectomy / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision / Q000401:mortality*; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate