Application of circulating tumor cell counting in diagnosis of patients with colorectal cancer / 中华消化杂志

ABSTRACT

Objective To explore the application value of circulating tumor cell (CTC) counting in the diagnosis of patients with colorectal cancer.Methods From July to October in 2015,a total of 61 patients firstly diagnosed with colorectal cancer,at stagc] to Ⅳ were enrolled.At the same period,20 individuals (healthy volunteers or patients with benign colorectal diseases) were selected as controls.Peripheral blood (7.5 mL) was taken before therapy.Peripheral blood CTC were counted by immunomagnetic beads enrichment combined with fluorescent staining method in two hours.The positive detection rate of CTC for colorectal cancer,especially early colorectal cancer was analyzed.And the priority of combination it with carcino-embryonic antigen (CEA) was also investigated.Chi-square test,t test and rank-sum test were used for statistical analysis.Results Two patients could not be pathological staged,due to the lack of whole body imaging evaluation.There were 30 patients with colorectal cancer at early stage (stage Ⅰ to Ⅱ) and 29 patients at advanced stage (stage Ⅲ to Ⅳ).The difference in CEA level between patients at early stage and advanced stage ((3.3±1.1) μg/L vs (20.4±3.3) μg/L) was statistically significant (t=-2.74,P=0.008).The median cell number of CTC of colorectal cancer group and control group was 1 (interquartile range=4) and 0,respectively,and the difference was statistically significant (Z=2.721,P=0.007).Taken 0/7.5 mL and 5 μg/L as the cut-off value of CTC and CEA,the detection rates of CTC for colorectal cancer and early colorectal cancer were 65.6％ (40/61) and 63.3％ (19/30),respectively;the detection rates of CEA for colorectal cancer and early colorectal cancer were 29.5 ％ (18/61) and 13.3％ (4/30).When CTC combined with CEA,the detection rates for colorectal cancer and early colorectal cancer were 73.8％ (45/61) and 66.7％ (20/30),respectively.Conclusions CTC has certain detection value in colorectal cancer especially early colorectal cancer.If it combined with CEA,the detection rate is much higher.