Value of serum and bile levels of IGF-1 in discriminating cholangiocarcinoma from other causes of extrahepatic biliary obstruction

Abstract

Cholangiocarcinoma (CCA) is a highly fatal malignant tumor with increasing incidence rates worldwide.  
Many biomarkers were suggested for diagnosis of CCA. Insulin-like growth factor 1 (IGF-1) stimulates 
mitosis, inhibits apoptosis and plays an important role in molecular pathogenesis of CCA. The aim of this 
study was to evaluate the performance of IGF-1 level in serum and bile as a diagnostic marker for 
extrahepatic CCA. The study was conducted on 127 patients with extrahepatic obstructive jaundice 
diagnosed as extrahepatic CCA (group 1, 45 cases), other malignant causes of extrahepatic obstructive 
jaundice (group 2, 37 cases) and benign causes of extrahepatic biliary obstruction (group 3, 45 cases). 
Level of IGF-1 was measured for all patients in collected serum samples as well as in bile samples collected 
during endoscopic retrograde cholangio-pancreatography (ERCP)  or through percutaneous transhepatic 
cholangio-drainage (PTCD). Results: Bile level of IGF-1 was significantly elevated in extrahepatic CCA 
patients in comparison to other groups (P<0.001). On the other hand, no significant difference in serum 
level of IGF-1 was noticed among different groups. Conclusion: Measurement of IGF-1 level in bile (but not 
in serum) can distinguish CCA from other causes of extrahepatic biliary obstruction.