Objectives: 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.
Methods: 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.
Results: 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.
Conclusions: 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.