title: Serum tumor antigen REG4 as a useful diagnostic biomarker in gastric cancer.
abstract: OBJECTIVE
  Serum biomarkers for the detection of gastric cancer are needed even now in order to find a larger number of candidates for suspected gastric cancer. We evaluated the usefulness of a novel serum marker, REG4, as compared to that of CA19-9, CEA, and pepsinogen.
  
  
  METHODS
  Pre-therapeutic sera were collected from 74 patients with gastric cancer and 106 healthy controls without any cancers. REG4, CEA, CA19-9, and pepsinogen serum levels were measured in each group. The cut-off value of REG4 was defined, and then the usefulness of REG4 was evaluated with a validation study that included sera collected from 37 patients with gastric cancer and 44 healthy controls without any cancers.
  
  
  RESULTS
  REG4 levels were significantly higher in early gastric cancer patients (median 8.42 ng/ml) than in controls (median 5.01 ng/ml) (p < 0.001), and in advanced gastric cancer patients (median 13.12 ng/ml) than in early gastric cancer patients (p < 0.02). A cut-off value of 6.67 ng/ml was defined using the receiver operating characteristics curve. The sensitivity for gastric cancer was 73.0%, the specificity was 70.8%, and the accuracy was 71.8%. Diagnostic accuracy of REG4 was superior to that of the other tests. In the validation study, the sensitivity for gastric cancer was 94.5%, the specificity was 31.8%, and the accuracy was 60.5%.
  
  
  CONCLUSIONS
  Serum REG4 level can be a useful indicator to distinguish between patients with gastric cancer and healthy subjects. This has the potential to be used as a screening serum marker for gastric cancers, including cancers in the early stages.
authors: Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors: Yuji
authors: Y
authors: Kobayashi
authors: Yasumasa
authors: Y
authors: Niwa
authors: Masahiro
authors: M
authors: Tajika
authors: Hiroki
authors: H
authors: Kawai
authors: Shinya
authors: S
authors: Kondo
authors: Kazuo
authors: K
authors: Hara
authors: Nobumasa
authors: N
authors: Mizuno
authors: Susumu
authors: S
authors: Hijioka
authors: Akira
authors: A
authors: Sawaki
authors: Keitaro
authors: K
authors: Matsuo
authors: Hidewaki
authors: H
authors: Nakagawa
authors: Yusuke
authors: Y
authors: Nakamura
authors: Kenji
authors: K
authors: Yamao
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000097:blood; D016022:Case-Control Studies; D016099:Endoscopy, Gastrointestinal; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D037181:Lectins, C-Type / Q000097:blood*; D000073718:Pancreatitis-Associated Proteins; D020116:Pepsinogen A / Q000097:blood; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013274:Stomach Neoplasms / Q000097:blood / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D037181:Lectins, C-Type; D000073718:Pancreatitis-Associated Proteins; C428528:REG4 protein, human; D020116:Pepsinogen A