Sensitive and quantitative detection of KRAS2 gene mutations in pancreatic duct juice differentiates patients with pancreatic cancer from chronic pancreatitis, potential for early detection

KRAS2 gene mutations are found in 75-90% of infiltrating pancreatic ductal adenocarcinomas but can also be present with other non-neoplastic pancreatic diseases. We recently developed a novel sensitive assay for point mutation detection, called “LigAmp”, which can detect one mutant molecule in the presence of 10,000 wild-type molecules and can quantify mutant DNA over a wide dynamic range. We analyzed KRAS2 mutations in surgically-collected pancreatic duct juice samples from patients with pancreatic adenocarcinoma (n=27) and chronic pancreatitis (n=9). DNA sequencing demonstrated that 17 of the 27 pancreatic cancers harbored KRAS2 mutations at codon 12, including G12D (GGT→GAT), G12V (GTT), and G12R (CGT). We determined the relative amounts of each KRAS2 mutant by simultaneously quantifying wild-type and mutant KRAS2 DNA. For all pancreatic adenocarcinoma patients, the dominant KRAS2 mutation detected in the pancreatic juice corresponded to that found in the primary cancer. Mutation levels were substantia...