title: Prediction of prognosis by the extent of lymph node involvement in squamous cell carcinoma of the thoracic esophagus.
abstract: OBJECTIVE
  Current criteria of the N-category in the TNM staging system for carcinoma of the esophagus needs further subgrouping due to its simplicity in mixing together patients with different prognosis.
  
  
  METHODS
  A retrospective cohort study of 186 patients (176 men and ten women; mean age, 59.9 years) with squamous cell carcinoma (SCC) of the thoracic esophagus who underwent esophagectomy followed by two-field lymphadenectomy and cervical lymph node sampling between 1992 and 1999 was conducted. A proposed N-category which involved dividing the nodal status into N0 (no nodal involvement), N1 (< or =4 nodes or < or =20% nodal involvement), and N2 (>4 nodes, or >20%, or non-regional nodal involvement) subgroups was used for survival analysis.
  
  
  RESULTS
  The overall 5-year cumulative survival rate was 27%. Lymph node metastases were identified in 101 (54.3%) patients. Cumulative survival rates were 46% at 4 years in the N0 group and 21% at 4 years in the N1 group, whereas no patients in N2 group survived longer than 3 years (P<0.01). A multivariable analysis revealed that independent prognostic factors included the depth of tumor invasion (P<0.01), nodal involvement (P<0.01), and organ metastasis (P<0.01).
  
  
  CONCLUSIONS
  In addition to the location of nodes, the extent of nodal involvement in SCC of the thoracic esophagus also plays an important role in prognosis prediction.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Taichung Veterans General Hospital, #160, Section 3, Taichung-Kang Road, Taichung, Taiwan. cliff@vghtc.vghtc.gov.tw
authors.forename: C P
authors.initials: CP
authors.lastname: Hsu
authors.forename: C Y
authors.initials: CY
authors.lastname: Chen
authors.forename: J Y
authors.initials: JY
authors.lastname: Hsia
authors.forename: S E
authors.initials: SE
authors.lastname: Shai
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; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis