DETECTION OF K-RAS GENE-MUTATIONS IN PLASMA DNA OF PATIENTS WITH PANCREATIC ADENOCARCINOMA - CORRELATION WITH CLINICOPATHOLOGICAL FEATURES

We investigated the presence of K-ras gene mutation in plasma DNA and assessed its clinical value in patients with pancreatic adenocarcinoma , Mutations in codon 12 of the K-l as gene were examined by mutant all ele-specific amplification method using DNA extracted from surgical sp ecimens and plasma samples of 21 patients with pancreatic adenocarcino ma, K-ras gene mutation was detected in 15 of 21 (71%) primary tumors. In 9 of 15 (60%) patients with K-ras gene mutation-positive tumors, a n identical mutation was detected in the plasma DNA, None of four pati ents with chronic pancreatitis or five healthy subjects had such mutat ions in plasma DNA, Tumors positive for K-ras gene mutation in plasma DNA were significantly larger (P = 0.04) and less likely to result in a curative cure after surgical resection (P = 0.09) than those negativ e for the mutation. Other clinicopathological features, including age, sex, histological type, mode of invasion, and metastasis, did not cor relate with K-ras gene mutations in plasma DNA, Treatment resulted in disappearance of K-ras gene mutations in plasma DNA in six of nine (67 %) patients. Three patients with a persistently positive K-ras gene mu tation in pre-and posttreatment plasma samples were likely to show ear ly recurrence or have a progressive disease. Our findings suggest that K-ras gene mutation can be detected in plasma DNA of patients with pa ncreatic adenocarcinoma, Detection of K-ras mutations in plasma may be clinically useful for evaluating tumor burden and efficacy of treatme nt.