Experimental Study On The Diagnosis Of Colorectal Cancer By The Combined Detection Of Serum MiRNA-29a And CEA

Objective:To investigate the expression of miRNA-29 a in serum of colorectal cancer patients,and analyze the diagnostic value of CRC traditional tumor screening marker CEA plus miRNA-29 a detections for colorectal cancer.Methods:1.30 patients with colorectal cancer,30 patients with colorectal adenomatous polyps,10 healthy volunteers,were selected from the First Hospital of Changsha City from February 2018 to February 2019.30 Colorectal cancer patients Divided into preoperative and postoperative two groups.2.The CEA level in serum samples of these people was detected by chemiluminescence immunoassay method,and the expression of miRNA-29 a was measured by using real-time fluorescent quantitative PCR method.Results:1.The expression level of miRNA-29 a was siginficantly upregulated in serum of CRC preoperative patients compared with the other three groups(all P<0.05).The expression level of miRNA-29 a was siginficantly below in serum of healthy volunteers compared with the CRC postoperative patients(P<0.05),which did not show siginficant difference between the colorectal adenomatous polyps patients and thehealthy volunteers(P>0.05).2.The expression levels of miRNA29 a were siginficantly associated with the lymph node metastasis,distant metastasis and TNM stage(all P<0.05).3.In the three groups above,the combined detection of serum miRNA-29 a and CEA expression levels significantly increased the diagnostic value of CRC compared with the expression level of each factor alone,and its specificity and sensitivity were significantly increased.4.Also in the three groups,the positive likelihood ratio(LR+)of CEA plus miRNA-29 a detections was more than 20,and the negative likelihood ratio(LR-)of which was less than 2,which conformed that screening tests had diagnostic value.Conclusion:1.The expression level of serum miRNA-29 a is elevated in CRC patients,the sensitivity and the specificity are higher than traditional colorectal cancer screening marker CEA.2.Serum miRNA-29 a may be involved in the distant metastasis and infiltration of colorectal cancer cells.3.CEA combined with miRNA-29 a detection will improve the diagnostic sensitivity and specificity of colorectal cancer.