title: Invasive Mediastinal Staging Guideline Concordance.
abstract: BACKGROUND
  Despite guidelines for preoperative invasive mediastinal staging (IMS) for non-small cell lung cancer (NSCLC), concordance with guidelines and whether the use of these guidelines results in expected frequency of lymph node metastases has not been evaluated. Our objectives were to determine guideline concordance, reasons for nonconcordance, and, in patients who did not receive IMS, to determine the use of operative nodal sampling and final pathologic staging.
  
  
  METHODS
  Patients who had a resection for NSCLC between 2010 and 2012 were identified from the Institutional Cancer Registry. A chart audit was performed to determine adherence to Cancer Care Ontario (CCO) IMS guideline criteria, and pathologic reports were reviewed to determine postresection staging.
  
  
  RESULTS
  Of 242 resections performed in the study period 102 (42%) did not receive IMS. 66 patients (65%) did not require IMS based on CCO guidelines and thus were concordant with guidelines, whereas 36 (36%) were guideline nonconcordant. Of 102 patients who did not have preoperative IMS, only 72 had intraoperative lymph node assessment and only 35 (34%) had sampling of three or more ipsilateral (N2) nodal stations. In the guideline concordant group, 2 of 66 patients (5%) had positive N2 nodes, whereas in the nonconcordant group 3 of 36 patients (11%) were N2 positive.
  
  
  CONCLUSIONS
  Although overall IMS was used in only 140 patients (58%), concordance with guidelines was high at 85% (206 of 242 patients). However, rates of intraoperative nodal sampling for non-IMS cases (both concordant and nonconcordant) was lower than expected, resulting in potentially understaged patients.
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada. Electronic address: anna.bendzsak@utoronto.ca.
authors.forename: Anna
authors.initials: A
authors.lastname: Bendzsak
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Waddell
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasufuku
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: de Perrot
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cypel
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Pierre
authors.affiliation: Division of Thoracic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gail E
authors.initials: GE
authors.lastname: Darling
mesh_terms: D000328:Adult; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008482:Mediastinum / Q000473:pathology; D009367:Neoplasm Staging / Q000706:statistics & numerical data*; D017410:Practice Guidelines as Topic; D012042:Registries