[Detection of K-ras gene mutations in DNA extracted from the plasma of patients with pancreatic cancer].

To detect mutations of the K-ras codon 12 in DNA extracted from the plasma of patients with pancreatic cancer, and to explore the possibility of using this method in early diagnosis of pancreatic cancer.Plasma DNA was isolated from the blood of 22 patients with pancreatic cancer and from 20 normal controls. K-ras codon 12 mutations were detected by mutant enriched polymerase chain reaction-restriction fragment length polymorphism technique and subsequent product sequencing. The relation of K-ras mutations in plasma to clinical features in pancreatic cancer patients was analyzed.Seventeen (77.3%) of 22 patients with pancreatic cancer had a codon 12 K-ras mutation in their plasma DNA. In two patients, the PCR products were sequenced and the mutations were confirmed. The occurrence of K-ras mutations in the plasma DNA was not related to tumor location, tumor size, and TNM stage. No K-ras mutation was detected in the plasma specimen of any of the normal controls.K-ras mutations are frequently found in the plasma DNA of patients with pancreatic cancer. Analysis of K-ras mutation in the plasma DNA may be useful in the early detection of pancreatic cancer.