Detection of c-Ki-ras mutations in bile samples from patients with pancreatic and biliary cancers

Aim-To determine whether c-Ki-ras mutations can be detected in bile from patients with biliary strictures caused by pancreatic cancer and other biliary tumours, with a view to developing bile c-Ki-ras mutations as a non-invasive diagnostic marker of pancreatic cancer.Methods-Bile was collected from 89 subjects (47 controls (including patients with bile duct stones or benign stricture), 20 patients with pancreatic cancer, 11 with cholangiocarcinoma, five with ampullary cancer, and six with metastatic biliary obstruction) referred for endoscopic retrograde cholangiopancreatography. DNA was extracted from bile and c-Ki-ras codon 12 mutations were detected using PCR and a restriction enzyme digestion method.Results-c-Ki-ras mutations were detected in 10 (50%) of 20 patients with pancreatic cancer, in one (9%) of 11 with cholangiocarcinoma, and in two (33%) of six patients with metastatic biliary obstruction (primary tumours: colon and prostate). C-Ki-ras mutations were not detected in the controls and patients with ampullary cancer.Conclusions-The sensitivity of this test is too low at 50% to recommend its use clinically, but with refinement has potential as a diagnostic marker for pancreatic cancer.