title: Accuracy of contemporary oesophageal cancer lymph node staging with radiological-pathological correlation.
abstract: OBJECTIVE
  To evaluate the accuracy of contemporary N-staging and provide radiological-pathological correlation in patients with lymph node metastases (LNMs) that were radiologically staged N0.
  
  
  METHODS
  One hundred and twelve patients were included who underwent surgery alone (n=41) or neoadjuvant therapy (n=71) between October 2010 and December 2015. Contrast-enhanced computed tomography (CECT), endoscopic ultrasound (EUS), and combined positron-emission tomography (PET) and CT N-stage were compared to pathological N-stage [node-negative (N0) versus node-positive (N+) groups]. Fifty LNMs from 15 patients preoperatively staged as N0 were measured and the maximum size recorded.
  
  
  RESULTS
  Accuracy, sensitivity, and specificity of N0 versus N+ disease with CECT, EUS, and PET/CT was 54.5%, 39.7% and 77.3%, 55.4%, 42.6% and 75%, and 57.1% 35.3%, and 90.9%, respectively. All techniques were more likely to under-stage nodal disease; CECT (X232.890, df=1, p<0.001), EUS (X228.471, df=1, p<0.001), and PET/CT (X250.790, df=1, p<0.001). PET/CT was more likely to under-stage nodal disease than EUS (p=0.031). Median LNM size was 3 mm, with 41 (82%) of LNMs measuring <6 mm and 22 (44%) classified as micro-metastases (≤2 mm).
  
  
  CONCLUSIONS
  This study has demonstrated poor N-staging accuracy in the modern era of radiological staging. Eighty-two percent of LNMs measured <6 mm, making direct identification extremely challenging on medical imaging. Future research should focus on investigating and developing alternative surrogate markers to predict the likelihood of LNMs.
authors.affiliation: Division of Cancer & Genetics, Cardiff University, Cardiff, UK. Electronic address: foleykg@cardiff.ac.uk.
authors.forename: K G
authors.initials: KG
authors.lastname: Foley
authors.affiliation: Department of Pathology, University Hospital of Wales, Cardiff, UK.
authors.forename: A
authors.initials: A
authors.lastname: Christian
authors.affiliation: Wales Research & Diagnostic PET Imaging Centre, Cardiff, UK.
authors.forename: P
authors.initials: P
authors.lastname: Fielding
authors.affiliation: Department of Upper GI Surgery, University Hospital of Wales, Cardiff, UK.
authors.forename: W G
authors.initials: WG
authors.lastname: Lewis
authors.affiliation: Department of Clinical Radiology, University Hospital of Wales, Cardiff, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Roberts
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D019160:Endosonography; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult