IDENTIFICATION OF K-RAS ONCOGENE MUTATIONS IN THE PURE PANCREATIC-JUICE OF PATIENTS WITH DUCTAL PANCREATIC CANCERS

Pancreatic cancer is detected on the basis of morphological changes de lineated by means of various image-diagnostic methods. However, differ entiation between chronic pancreatitis and pancreatic cancer, especial ly at the early stage, is not always simple when based upon the morpho logical changes alone. Therefore, we attempted to elucidate K-ras muta tions in the sediment of pure pancreatic juice (PPJ) containing exfoli ated ductal pancreatic cancer cells. PPJ was collected endoscopically from 20 patients with pancreatic cancer (PC) and 18 patients with chro nic pancreatitis (CP). Polymerase chain reaction and allele specific o ligonucleotide dot blot hybridization for K-ras mutations were perform ed with the DNA extracted from these samples. A K-ras mutation at codo n 12 was identified in the PPJ of 11/20 (55%) of the patients with PC. On the other hand, the same mutation was not identified in the PPJ of any patient with CP. Moreover, K-ras mutations at codons 13 and 61 we re not recognized in the PPJ of any patient with either PC or CP. Thes e findings suggested that the presence of a K-ras mutation at codon 12 in PPJ would be useful in confirming the diagnosis of PC.