title: The diagnostic validity of the (13)c-urea breath test in the gastrectomized patients: single tertiary center retrospective cohort study.
abstract: BACKGROUND
  This study was conducted to evaluate the diagnostic validity of the (13)C-urea breath test ((13)C-UBT) in the remnant stomach after partial gastrectomy for gastric cancer.
  
  
  METHODS
  The (13)C-UBT results after Helicobacter pylori eradication therapy was compared with the results of endoscopic biopsy-based methods in the patients who have received partial gastrectomy for the gastric cancer.
  
  
  RESULTS
  Among the gastrectomized patients who showed the positive (13)C-UBT results (≥ 2.5‰, n = 47) and negative (13)C-UBT results (< 2.5‰, n = 114) after H. pylori eradication, 26 patients (16.1%) and 4 patients (2.5%) were found to show false positive and false negative results based on biopsy-based methods, respectively. The sensitivity, specificity, false positive rate, and false negative rate for the cut-off value of 2.5‰ were 84.0%, 80.9%, 19.1%, and 16.0%, respectively. The positive and negative predictive values were 44.7% and 96.5%, respectively. In the multivariate analysis, two or more H. pylori eradication therapies (odds ratio = 3.248, 95% confidence interval= 1.088-9.695, P = 0.035) was associated with a false positive result of the (13)C-UBT.
  
  
  CONCLUSIONS
  After partial gastrectomy, a discordant result was shown in the positive (13)C-UBT results compared to the endoscopic biopsy methods for confirming the H. pylori status after eradication. Additional endoscopic biopsy-based H. pylori tests would be helpful to avoid unnecessary treatment for H. pylori eradication in these cases.
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Yong Hwan
authors.initials: YH
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ju Yup
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Yoon Jin
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Kichul
authors.initials: K
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
keywords: 13C-urea breath test; Cut-off value; Eradication; Helicobacter pylori; Subtotal gastrectomy