The clinical significance of K-ras mutation detected in plasma cell-free DNA from patients with colorectal carcinoma / 重庆医学

ABSTRACT

Objective To evaluate the clinical significance of K-ras mutation in plasma cell-free DNA from patients with colorec-tal carcinoma .Methods Plasma cell-free DNA in 212 patients with colorectal carcinoma were extracted and identified by Globin gene .K-ras mutation was amplified by RE-PCR and compared with results of pathological biopsy samples DNA .Results Plasma cell-free DNA were successfully obtained from 212 cases .But no plasma cell-free DNA were found in normal control .Out of 212 ca-ses ,34 cases showed K-ras mutation(16 .00% )in cell-free DNA ,and 33 cases showed positive in pathological biopsy samples DNA (15 .57% ) .It was found two kinds of K-ras mutation on code 12-GGT to GAT ;GGT to GTT .K-ras mutation was not related to tumors′position(χ2 =3 .34 ,P=0 .61);to differentiation degree(χ2 =2 .38 ,P=0 .29);to Dukes staging(χ2 = 2 .84 ,P=0 .38);to lymphoid nodes′metastasis(χ2 =0 .98 ,P=0 .37);to age(χ2 =1 .86 ,P=0 .39) .Conclusion Tumor-derived DNA can be detected in plasma of underlying cancer patients .For colorectal carcinoma patients ,detecting K-ras mutation of plasma cell-free DNA have the same clinical significance as biopsy samples .Moreover ,it′s more convenient and non-invasive .