Clinical significance of cathepsin E in pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma

Background: It has been reported that cathepsin E (CTSE) is a non-secretory and intracellular aspartic proteinase found in the superficial epithelial cells of the stomach and that it is also expressed in pancreatic ductal ade nocarcinoma. We evaluated the diagnostic value of CTSE in the pancreatic ju ice in the diagnosis of pancreatic ductal adenocarcinoma compared with that of CA19-9, carcinoembryonic antigen (CEA) and K-ras mutations. Methods: One hundred and one patients (25 with pancreatic ductal adenocarci noma and 76 with chronic pancreatitis) were examined for the diagnostic sig nificance of CTSE in the pancreatic juice in the diagnosis of pancreatic du ctal adenocarcinoma. Forty of 101 patients (15 with pancreatic ductal adeno carcinoma and 25 with chronic pancreatitis) were examined to compare the di agnostic value of various tumor markers in the pancreatic juice, namely CA1 9-9, CEA, K-ras mutations and CTSE. Results: The detection frequency of CTSE was significantly higher in patien ts with pancreatic ductal adenocarcinoma (64.0%) than in patients with chro nic pancreatitis (7.9%; chi (2) = 34.76; P < 0.0001). The sensitivity, spec ificity and diagnostic accuracy of CTSE in the pancreatic juice for pancrea tic ductal adenocarcinoma was 66.7, 92.0 and 82.5%, respectively. These val ues were more efficient in comparison with those of CA19-9, CEA and K-ras m utations. The main cause of the detection failure of CTSE in pancreatic duc tal adenocarcinoma was obstruction of the main pancreatic duct. Sensitivity was 85.7% in patients without obstruction of the main pancreatic duct. Conclusions: Cathepsin E in the pancreatic juice is a novel marker for a de finitive diagnosis of pancreatic ductal adenocarcinoma. (C) 2000 Blackwell Science Asia Pty Ltd.