title: Impact of the number of lymph nodes sampled on outcome in ypT0N0 esophageal squamous cell carcinoma patients.
abstract: BACKGROUND
  Higher extent of lymph node dissection (LND) is beneficial in primarily resected esophageal cancer patients by providing accurate staging and better tumor control. Achieving pathological complete response (pCR) after chemoradiotherapy (CRT) also represents better outcome. We studied the controversial question whether higher LND could further improve survival after pCR.
  
  
  METHODS
  Between 1996 and 2007, Esophageal squamous cell carcinoma (ESCC) patients with pCR after CRT were included. Based on the median number of dissected lymph node, patients were divided into two groups (Group 1: Lower LND; Group 2: Higher LND). We compared the demographic features, perioperative outcomes, recurrence, and survival between groups.
  
  
  RESULTS
  The cohort comprised 101 patients (100 males and one female) with a mean age of 58 years. There were 56 and 45 patients in Group 1 and 2, respectively. Clinical features and perioperative outcome were similar between groups. During a mean follow-up of 78.8 months, 32 (33.7%) patients died of the disease and 35.8% of patients developed recurrence. There was no difference in locoregional (11.3% vs. 9.5%, P=0.78) or distant recurrence (22.6% vs. 33.3%, P=0.18) between the two groups. Patients with lowest LND also had similar outcomes as those with the highest LND. The 5-year disease specific survival rate was 65 and 64% in Group 1 and 2, respectively.
  
  
  CONCLUSIONS
  In ESCC patients, the number of negative lymph nodes had no prognostic impact after pCR.
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Keelung, College of Medicine, Chang Gung University, Taoyuan, Taiwan. chaoyk@cgmh.org.tw
authors.forename: Yin-Kai
authors.initials: YK
authors.lastname: Chao
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Liu
authors.forename: Ming-Ju
authors.initials: MJ
authors.lastname: Hsieh
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Wu
authors.forename: Yun-Hen
authors.initials: YH
authors.lastname: Liu
authors.forename: Chi-Hsiao
authors.initials: CH
authors.lastname: Yeh
authors.forename: Hsien-Kun
authors.initials: HK
authors.lastname: Chang
authors.forename: Chen-Kan
authors.initials: CK
authors.lastname: Tseng
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D059248:Chemoradiotherapy; D004938:Esophageal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome