title: Resection of thymoma should include nodal sampling.
abstract: OBJECTIVE
  Thymoma is best treated by surgical resection; however, no clear guidelines have been created regarding lymph node sampling at the time of resection. Additionally, the prognostic implications of nodal metastases are unclear. The aim of this study was to analyze the prognostic implications of nodal metastases in thymoma.
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results database was queried for patients who underwent surgical resection of thymoma with documented pathologic examination of lymph nodes. The impact of nodal status on survival and thymoma staging was examined.
  
  
  RESULTS
  We identified 442 patients who underwent thymoma resection with pathologic evaluation of 1 or more lymph nodes. A median of 2 nodes were sampled per patient. Fifty-nine patients (59 of 442, 13.3%) had ≥ 1 positive node. Patients with positive nodes were younger and had smaller tumors than node-negative patients. Median survival in the node-positive patients was 98 months, compared with 144 months in node-negative patients (P = .013). In multivariable analysis, the presence of positive nodes had a significant, independent, adverse impact on survival (hazard ratio 1.945, 95% confidence interval 1.296-2.919, P = .001). The presence of nodal metastases resulted in a change in classification to a higher stage in 80% of patients, the majority from Masaoka-Koga stage III to stage IV.
  
  
  CONCLUSIONS
  Nodal status seems to be an important prognostic factor in patients with thymoma. Until the prognostic significance of nodal metastases is better understood, surgical therapy for thymoma should include sampling of regional lymph nodes.
authors.affiliation: Division of Thoracic Surgery, University of Tennessee Health Science Center, Memphis, Tenn. Electronic address: bweksler@uthsc.edu.
authors.forename: Benny
authors.initials: B
authors.lastname: Weksler
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Arjun
authors.initials: A
authors.lastname: Pennathur
authors.affiliation: Division of Thoracic Surgery, University of Tennessee Health Science Center, Memphis, Tenn.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Sullivan
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Katie S
authors.initials: KS
authors.lastname: Nason
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D018426:SEER Program; D013934:Thymectomy; D013945:Thymoma / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D047368:Tumor Burden; D014481:United States