The value of peripheral blood circulating tumor cells in KRAS mutation testing of colorectal cancer patients / 国际肿瘤学杂志

ABSTRACT

Objective To explore the value of peripheral blood samples in KRAS mutation testing of colorectal cancer patients and the correlation between the number of circulating tumor cells and KRAS mutation testing.Methods We detected KRAS mutation using amplification refractory mutation system PCR method in paraffin embedded tissues and matched peripheral blood samples obtained from 112 colorectal cancer patients and 10 proctitic peripheral blood samples in Affiliated Hospital of Jiangnan University between 2013 and 2014.Meanwhile,immunofluorescence in situ hybridization method was used to count the circulating tumor cells in peripheral blood samples and proctitic control samples.Results Among the 112 colorectal cancer samples tested,25 cases of peripheral blood samples found KRAS mutation (41.1％) and which was 46 in formalin fixed paraffin embedded tissues testing (22.3 ％),with a significant difference (x2 =40.12,P ＜ 0.001).One case with KRAS wild type in formalin fixed paraffin embedded tissues was mutation type in peripheral samples.In another case,mutation site was different in different kinds of samples.The sensibility of KRAS mutation testing was 73.3％,41.9％ and 16.7％ when the number of circulating tumor cells was more than 15,5 to 15,and 1 to 5,respectively,with significant differences (x2 =23.70,P ＜ 0.001).No KRAS mutation and no circulating tumor cells were found in 10 proctitic control samples.Conclusion We find high specificity in KRAS mutation testing of peripheral blood samples.but the accurate rate is not satisfying.KRAS mutation testing in peripheral blood samples may be an optional choice to test KRAS mutations for colorectal cancer patients who were not subjected to surgery.The sensibility of KRAS mutation testing in peripheral blood samples has a corretion with the number of circulating tumor cells.