title: Combination of DKK1 and AFP improves diagnostic accuracy of hepatocellular carcinoma compared with either marker alone.
abstract: OBJECTIVE
  The Wnt/ß-catenin pathway plays a prominent role in hepatocellular carcinoma (HCC). The Dickkopf (DKK) proteins (DKK1-4) are known Wnt antagonists; the overexpression of DKK1 has been demonstrated in HCC, and increased DKK3 methylation in the HCC tissue is associated with worse prognosis. Thus, the aim of our study was to demonstrate the diagnostic accuracy of serum DKK1 and DKK3 in HCC in comparison with that of serum alpha-fetoprotein (AFP).
  
  
  METHODS
  We included consecutive 40 HCC patients, 54 cirrhosis patients, and 39 healthy controls. Serum DKK1 and DKK3 levels were measured by an enzyme-linked immunosorbent assay, and serum AFP levels were measured by a chemiluminescence assay.
  
  
  RESULTS
  The AFP levels differed in each group and could help differentiate between groups (p < 0.001). The DKK1 levels could help differentiate the HCC group from cirrhosis and control groups (p < 0.001), and the DKK3 levels could help differentiate HCC and cirrhosis groups from the control group (p < 0.001). Combined usage of DKK1 and AFP increased the diagnostic yield, with a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 92.3%, 92.1%, and 87.8%, respectively.
  
  
  CONCLUSIONS
  Although AFP is superior to DKK1 and DKK3 in the diagnosis of HCC, the combination of DKK1 and AFP showed a better diagnostic yield than AFP alone.
authors.affiliation: Department of Gastroenterology, Gazi University School of Medicine, Ankara, Turkey. idogan@gmail.com.
authors.forename: Harun
authors.initials: H
authors.lastname: Erdal
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Gül Utku
authors.forename: Eylem
authors.initials: E
authors.lastname: Karatay
authors.forename: Bülent
authors.initials: B
authors.lastname: Çelik
authors.forename: Şehri
authors.initials: Ş
authors.lastname: Elbeg
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Doğan
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D016022:Case-Control Studies; D018925:Chemokines; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005355:Fibrosis / Q000175:diagnosis; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: C097353:AFP protein, human; D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; D018925:Chemokines; C501126:DKK1 protein, human; C498624:DKK3 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D000509:alpha-Fetoproteins