Biliary and Serum Insulin-Like Growth Factor-I: Are They Reliable Diagnostic Markers in Cholangiocarcinoma?

4 Abstract: Cholangiocarcinoma (CCA), the commonest biliary malignancy, is difficult to diagnose owing to its anatomic location, growth patterns and lack of definite diagnostic criteria. CCA cells express and secrete insulin- like growth factor I (IGF-I) which participate in the modulation of enhancing cell growth and reducing apoptosis. Measuring IGF-I in bile and serum of patients with cholangiocarcinoma and to evaluate them as diagnostic markers. This was a cross sectional study that included 60 patients who had endoscopic retrograde cholangio- pancreatography (ERCP), including 20 patients with cholangiocarcinoma, 20 patients with pancreatic cancer and 20 patients with benign biliary abnormalities. Mean biliary IGF-I level, in patients with cholangiocarcinoma, was 14 fold higher than patients with pancreatic cancer and 19 fold higher than in those with benign biliary abnormalities with high statistical significance (each recorded p< 0.001). Biliary, not serum, IGF-1 proved to be a significant discriminator between the studied groups (AUC=1), moreover, IGF-1 assay was independent from degree of obstruction. Biliary IGF-I is a reliable marker in differentiating CCA from other causes of extrahepatic biliary obstruction.