title: Use of endoscopic ultrasound in the preoperative staging of gastric cancer: a multi-institutional study of the US gastric cancer collaborative.
abstract: BACKGROUND
  Endoscopic ultrasound (EUS) can be used to guide the therapeutic plan for patients with gastric adenocarcinoma (GAC), but data on its use and accuracy remain poorly defined. We sought to define the use of EUS, as well as characterize the diagnostic accuracy of EUS among patients with GAC.
  
  
  METHODS
  We identified 960 patients who underwent resection of GAC between 2000 and 2012 from 7 major academic institutions participating in the US Gastric Cancer Collaborative. Clinicopathologic and EUS data were collected and analyzed using chi and kappa statistics.
  
  
  RESULTS
  Of 960 patients, 223 (23.2%) underwent evaluation with preoperative EUS. Among patients who underwent EUS, 74 (33.2%) received neoadjuvant chemotherapy; 149 (66.8%) proceeded directly to resection. Among patients who did not receive neoadjuvant therapy and received curative intent gastric resection, the EUS T classifications were T1 (33.3%), T2 (35.6%), T3 (18.9%), T4 (12.1%) and the N classifications were N0 (68.1%) and N ≥ 1 (31.9%). In contrast, when tumor stage was based on the final surgical specimen, there was a higher proportion of cases with more advanced T stage (T1, 36.4%; T2, 14.4%; T3, 23.5%; T4, 25.7%) and N stage (N0, 51.3%; N ≥ 1, 48.7%). The agreement of preoperative EUS compared with surgical staging for T (kappa = 0.28, p < 0.001) and N (kappa = 0.33, p < 0.001) classification was only fair.
  
  
  CONCLUSIONS
  Less than one-quarter of patients with GAC underwent preoperative EUS staging. In patients who did not receive preoperative chemotherapy, tumor stage on EUS often did not correlate with T stage and N stage on final pathologic analysis. Endoscopic ultrasound should be combined with other staging modalities to optimize staging of patients with GAC.
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Gaya
authors.initials: G
authors.lastname: Spolverato
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Aslam
authors.initials: A
authors.lastname: Ejaz
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Yuhree
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Surgery, Division of Surgical Oncology, Winship Cancer Institute, Emory University, Atlanta, GA.
authors.forename: Malcolm H
authors.initials: MH
authors.lastname: Squires
authors.affiliation: Department of Surgery, Stanford University, Palo Alto, CA.
authors.forename: George A
authors.initials: GA
authors.lastname: Poultsides
authors.affiliation: Department of Surgery and the Alvin J Siteman Cancer Center, Washington University School of Medicine, St Louis, MO.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Fields
authors.affiliation: Department of Surgery, The Ohio State University, Columbus, OH.
authors.forename: Carl
authors.initials: C
authors.lastname: Schmidt
authors.affiliation: Department of Surgery, Division of Surgical Oncology, University of Wisconsin, Madison, WI.
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Weber
authors.affiliation: Department of Surgery, Wake Forest University, Winston-Salem, NC.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Votanopoulos
authors.affiliation: Department of Surgery, Division of Surgical Oncology, Winship Cancer Institute, Emory University, Atlanta, GA.
authors.forename: Shishir K
authors.initials: SK
authors.lastname: Maithel
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD. Electronic address: tpawlik1@jhmi.edu.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019160:Endosonography / Q000706:statistics & numerical data; D005260:Female; D005743:Gastrectomy; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011300:Preoperative Care / Q000379:methods* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D014481:United States