A PROSPECTIVE-STUDY OF K-RAS MUTATIONS IN THE PLASMA OF PANCREATIC-CANCER PATIENTS

K-ras mutations are frequently found in primary pancreatic adenocarcin omas. In this prospective study, we looked for K-ras mutations in the plasma of patients with pancreatic cancer, We isolated plasma DNA from 21 pancreatic cancer patients using a simple and rapid extraction tec hnique and detected K-ras alterations with a PCR assay and subsequent product sequencing, Patients were followed up to determine their clini cal outcome, We found K-ras mutations in the plasma of 17 patients (81 %), In cases in which both plasma and pancreatic tissue were available , DNA mutations were similar in corresponding plasma and tissue sample s. Plasma DNA alterations were found 5-14 months before clinical diagn osis in four patients, Mutant DNA was not found in the plasma of two p atients with chronic pancreatitis or in five healthy controls, Our res ults indicate that K-ras mutations are often found in DNA isolated fro m the plasma of pancreatic cancer patients and that a noninvasive plas ma-based assay may provide qualitative diagnostic information to clini cians in the future, Larger studies are required to further assess the relevance of our findings to clinical practice.