title: Serum dickkopf-1 is a novel serological biomarker for the diagnosis and prognosis of pancreatic cancer.
abstract: OBJECTIVE
  To identify whether Dickkopf-1 (DKK1) could be a potential biomarker for early detection and prognosis in patients with pancreatic cancer (PC).
  
  
  METHODS
  Serum was collected from 140 patients with pancreatic adenocarcinoma and 92 control patients without pancreatic adenocarcinoma. Serological levels of DKK1 were examined by enzyme-linked immunosorbent assay (ELISA). The sensitivity and specificity was compared with carbohydrate antigen 19-9 (CA19-9). A 2-year follow-up was monitored to evaluate the correlation between DKK1 serum levels and overall survival. The expression of DKK1 in PC tumor tissues was also evaluated using immunohistochemistry staining.
  
  
  RESULTS
  Serum levels of DKK1 and CA19-9 were elevated in PC patients in the early-stage cases. These levels increased with the advancement of clinical stage. There was significant difference in DKK1 serum levels between early and advanced PC stages. Receiver operating characteristic curve (ROCC) analysis showed that DKK1 was significantly better than CA19-9 in differentiating patients with PC from the controls (area under the curve (AUC) 0.919 versus 0.853, respectively), especially in distinguishing early-stage cancer from chronic pancreatitis (CP). The expression of DKK1 in PC tissues correlated with its expression in serum samples. The overall survival rate was 24.4% in the group with higher DKK1 levels and was found to be significantly different from the group with lower DKK1 levels (33.3%).
  
  
  CONCLUSIONS
  DKK1 may be a novel diagnostic/prognostic biomarker for PC.
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Su-xia
authors.initials: SX
authors.lastname: Han
authors.affiliation: Department of Biotherapy, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Sui
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Chen-chen
authors.initials: CC
authors.lastname: He
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Meng-jiao
authors.initials: MJ
authors.lastname: Cai
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Jin-lu
authors.initials: JL
authors.lastname: Ma
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Yuan-yuan
authors.initials: YY
authors.lastname: Zhang
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Cong-ya
authors.initials: CY
authors.lastname: Zhou
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Chen-xian
authors.initials: CX
authors.lastname: Ma
authors.affiliation: Department of Biological Sciences and Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, USA.
authors.forename: Armando
authors.initials: A
authors.lastname: Varela-Ramirez
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an, Shaanxi, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood* / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000628:therapy; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis / Q000097:blood*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000628:therapy; D011237:Predictive Value of Tests; D012372:ROC Curve; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; C501126:DKK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins
keywords: diagnosis; dickkopf-1 (DKK1); pancreatic cancer (PC); prognosis; serum biomarker