Detection of K-ras point mutations at codon 12 in pure pancreatic juice for the diagnosis of pancreatic cancer by PCR-RFLP analysis

The present study was undertaken to detect K-ras point mutations at codon 12 in pure pancreatic juice (PPJ) for the diagnosis of pancreatic cancer (PC) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. PPJ was collected through a cannula under a duodenal fiberscope from 26 patients with PC and 32 patients with chronic pancreatitis (CP). DNA was extracted from PPJ and was used as the template for PCR. Analysis of PPJ by PCR-RFLP with BstNI revealed that the incidence of K-ras point mutations at codon 12 was 81% (21/26) in patients with PC and 6% (2/32) in those with CP. With reference to the location of PC, the incidence of K-ras mutations was 79% (11/14) in the head, 86% (6/7) in the body, and 80% (4/5) in the tail of the pancreas. The incidence of K-ras mutants was 50% (1/2) in tumor size 1 (TS1; less than or equal to 2.0 cm in size), 71% (5/7) in TS2 (2.1 to less than or equal to 4.0 cm), 89% (8/9) in TS3 (4.1 to less than or equal to 6.0 cm), and 88% (7/8) in TS4 (>6.1 cm). These results suggested that analysis of K-ras point mutations at codon 12 in PPJ using the PCR-RFLP method is a promising new genetic test for the diagnosis of PC.