Biliary concentration of CA19-9 and CA125, iron metabolism markers, and PIVKA-II activity in pancreatobiliary tumors

Objectives: Biliary tract cancers (cholangiocarcinoma/gallbladder cancer – CCA/GCA) and pancreatic cancers (PC) are one of the most aggressive tumors with poor prognosis, frequently diagnosed at advanced stages. Current diagnostic methods are unsatisfactory. This study evaluated diagnostic yield of selected biliary biomarkers. Methods: A prospective study enrolled 80 patients treated with endoscopic retrograde cholangiopancreatography (ERCP) because of: choledocholithiasis (n=50), CCA/GCA (n=13), and PC (n=17). Bile samples collected during ERCP were analyzed with electrochemiluminescence immunoassay (ECLIA) for CA19-9, PIVKA-II, osteocalcin, AFP, CA15-3, CEA and ferritin, chemiluminescent immunoassay (CMIA) for CA125, colorimetric analysis for iron and Total Iron Binding Capacity (TIBC), as well as enzyme-linked immunosorbent assay (ELISA) for hepcidin. Results: Several analyzed biomarkers demonstrated statistically significant differences in bile concentrations between patients with choledocholithiasis and malignant diseases. Particularly notable difference was observed for hepcidin and CA125. The biliary iron concentration and TIBC were inconclusive. PIVKA-II protein was confirmed as a reliable qualitative tumor marker. Attempts to detect osteocalcin, AFP, CA15-3, and CEA in bile failed due to concentrations being below the detectable threshold. No markers differentiated accurately the tumor type (p>0.05). Conclusions: CA125 and hepcidin as quantitative markers, along with PIVKA-II as a qualitative marker, demonstrate significant potential as biliary markers for distinguishing choledocholithiasis from biliary tract or pancreatic cancers. Biliary iron, TIBC, and CA19-9 require further investigation to confirm their diagnostic yield.