K-ras mutations in the plasma of colorectal cancer patients

Abstract

Background: We cannot always obtain the primary foci of colorectal cancer (CRC) for K-ras examinations in the clinical practice. In this study, we analyzed K-ras in patients' plasma. Methods: The DNA of 100 patients' plasma and their primary foci with CRC were extracted, and K-ras was examined using polymerase chain reaction (PCR) and sequencing analysis. Results: Seventy-three of 100 patients' plasma were analyzed. K-ras mutations were found in 10 of 73 patients' plasma and 34 of 100 primary foci. The 28.6% patients classified in the D stage by Dukes' staging were found to have K-ras mutations in their plasma, and 94.3% of the patients' plasma had consistent K-ras status with their primary foci. Conclusions: The detection of K-ras in patients' plasma for diagnosis is perhaps insignificant in the early stage of cases, but it is significant to the patients classified in the D stage by Dukes' staging.