DETECTION OF RAS GENE-MUTATIONS IN PANCREATIC-JUICE AND PERIPHERAL-BLOOD OF PATIENTS WITH PANCREATIC ADENOCARCINOMA

Pancreatic adenocarcinomas are known to have a high incidence of K-ras gene mutations. Differential diagnosis of pancreatic cancer and chron ic pancreatitis sometimes presents a clinical dilemma. We recently dev eloped a highly sensitive and specific polymerase chain reaction capab le of detecting 3-30 copies of mutant K-ras genes harboring codon 12 s ingle base changes in the presence of 300,000 normal copies. Mutant ra s genes were detected in DNA purified from pancreatic juice from all 6 cases of pancreatic adenocarcinoma and 1 case of intraductal papillar y neoplasms of the pancreas. In 2 of 6 other cases with pancreatic ade nocarcinoma. circulating metastatic cells were detected in DNA purifie d from peripheral blood. Activated ras genes were not found in pancrea tic juice of three control cases (chronic pancreatitis and choledochol ithiasis) or in the peripheral blood of two patients with insulinomas. Notable conclusions of this study are that there can be significant l evels of shed tumor cells in peripheral blood and an even higher numbe r in pancreatic juice. In addition. two different K-ras mutations were found in some patients.