title: Adjuvant radiation therapy and lymphadenectomy in esophageal cancer: a SEER database analysis.
abstract: OBJECTIVE
  This study seeks to determine the effects of postoperative radiation therapy and lymphadenectomy on survival in esophageal cancer.
  
  
  METHODS
  An analysis of patients with surgically resected esophageal cancer from the SEER database between 2004 and 2008 was performed to determine association of adjuvant radiation and lymph node dissection on survival. Survival curves were calculated according to the Kaplan-Meier method and log-rank analysis. Multivariate analysis (MVA) was performed by the Cox proportional hazard model.
  
  
  RESULTS
  We identified 2109 patients who met inclusion criteria. Radiation was associated with increased survival in stage III patients (p = 0.005), no benefit in stage II (p = 0.075) and IV (p = 0.913) patients, and decreased survival in stage I patients (p < 0.0001). Univariate analysis revealed that radiation therapy was associated with a survival benefit node positive (N1) patients while it was associated with a detriment in survival for node negative (N0) patients. Removing >12 and >15 lymph nodes was associated with increased survival in N0 patients, while removing >8, >10, >12, >15, and >20 lymph nodes was associated with a survival benefit in N1 patients. MVA revealed that age, gender, tumor and nodal stage, tumor location, and number of lymph nodes removed were prognostic for survival in N0 patients. In N1 patients, MVA showed the age, tumor stage, number of lymph nodes removed, and radiation were prognostic for survival.
  
  
  CONCLUSIONS
  The number of lymph nodes removed in esophageal cancer is associated with increased survival. The benefit of adjuvant radiation therapy on survival in esophageal cancer is limited to N1 patients.
authors.affiliation: Department of Radiation Oncology, H. Lee Moffitt Cancer Center, Tampa, FL 33612, USA. Ravi.Shridhar@moffitt.org
authors.forename: Ravi
authors.initials: R
authors.lastname: Shridhar
authors.forename: Jill
authors.initials: J
authors.lastname: Weber
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hoffe
authors.forename: Khaldoun
authors.initials: K
authors.lastname: Almhanna
authors.forename: Richard
authors.initials: R
authors.lastname: Karl
authors.forename: Kenneth
authors.initials: K
authors.lastname: Meredith
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000556:secondary* / Q000628:therapy*; D004938:Esophageal Neoplasms / Q000473:pathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D018426:SEER Program; D012737:Sex Factors