Detection of K-ras mutation in DNA extracted from the plasma of patients with colorectal cancer / 中华消化杂志

ABSTRACT

Objective The purpose of this study was to determine the value of K-ras mutation in DNA extracted from the plasma as clinical indicator of colorectal cancer. Methods Point mutation at codon 12 of K-ras gene was assayed by polymerase chain reaction of sequence-specific primers in DNA extracted from the plasma and tumors from 32 patients with colorectal cancer. The mutation was further confirmed by dideoxy-mediated chain-termination method of DNA sequencing. Results Fourteen patients (44%) had a codon 12 K-ras mutation within their primary tumors and identical mutations were found in the plasma DNA of 13 patients (93%). Mutant DNA was not detected in the plasma specimens of 18 patients whose tumors tested negative for K-ras alterations or in 5 healthy control subjects. Conclusion Preliminary results suggest the detection of K-ras mutations in circulating DNA extracted from the plasma specimens may have some clinical uti- lity in the detection of colorectal cancer.