Study On Clinical Value Of Diagnosis And Treatment By Detection Of Circulating Tumor Cells In Peripheral Blood Of Colorectal Cancer Patients

Objective: The study detects circulating tumor cells in peripheral blood of colorectal cancer patients by density gradient centrifugation and flow cytometry,and analyse the relationship of circulating tumor cells and the depth of tumor invasion, lymph node metastasis, TNM stage, tumor differentiation. This study aim to investigate the clinical value of using flow cytometry tto detect tumor cells in peripheral blood circulating of colorectal cancer patients. Methods: 1 10 ml peripheral blood from 60 colorectal cancer patients respectively in gastrointestinal surgery department of Affiliated Hospital of Putian College in May 1, 2014 to January 31, 2015. 10 ml peripheral blood were collected respectively from 15 healthy volunteers in period of June 1,2014 to November 31,2014 as control group. 2 Preparation of peripheral blood lymphocytes that isolated from peripheral blood mononuclear cell suspension into a test tube and flat control tubes,test tubes labeled CK19, EP-CAM, CD45 monoclonal antibodies. Negative control tubes were added CK19, EP-CAM, CD45 isotype control antibody. 3 The research make detection of CK19+/ EP-CAM +/CD45- cells by flow cytometry in the marked peripheral blood mononuclear cells as a marker of CTC colorectal cancer. 4 The results were processed with SPSS 13 statistical software package, and analysed by x2 test statistics,With P<0.05 as statistically significant. Results: In statistical analysis of the peripherial blood, 43.33%(26 out 60) of colorectal cancer patients were positive for CTC detection.All 15 healthy individuals were negative for CTC detection. 2 According to the different clinical TNM stage(Ⅰ,Ⅱ,Ⅲ and Ⅳ), CTC positive rate of 60 cases of colorectal cancer patients were 10.00%, 35.71%, 52.94% and 100.00% respectively, the positive rate of the four groups was statistically significant(P <0.05); According to different lymph node status(N0, N1, N2 period), CTC positive rates were 25.00%, 50.00%, 75.00% respectively, the positive rate of the three groups was statistically significant(P <0.05); According to different clinical tumor invasive depth(T1, T2, T3, T4 period), CTC positive rates of patients were 12.50%, 26.67%, 45.83%, 76.92% respectively, the positive rate of the four groups were statistically significant differences(P<0.05). According to the different degree of tumor differentiation(well differentiated, moderately differentiated, poorly differentiated), CTC positive rates were 22.22%, 41.67%, 66.67% respectively. The positive rate of the three groups were statistically significant differences(P <0.05). Conclusions: 1 The technology of flow cytometry can be applied to detect CTC in peripheral blood of colorectal cancer patients. 2 The clinical stage、tumor invasive depth、the number of lymph node metastasis、tumor differentiation of colorectal cancer patients are positively related with CTC detection rate, and the difference is statistically significant. Key Words: colorectal cancer;circulating tumor cell;CK19;EP-CAM;CD45.