Study On The Diagnostic Value Of CEA,CA-199,CA72-4 Combined With Intestinal Flora In Colorectal Cancer

Objective:To investigate the differences in the distribution and abundance of intestinal flora in colorectal cancer patients,adenoma patients and healthy subjects,and screen out the different flora,and further analyze the diagnostic value of combined diagnosis with tumor markers CEA,CA72-4 and CA-199.Methods:A total of 90 patients admitted to the First Affiliated Hospital of Xinjiang Medical University from June 2021 to December2021 were enrolled and divided into colorectal cancer group,adenoma group and healthy group,each with 30 cases.Blood and stool specimens were collected,and the sequencing technology of 16 Sr RNA and QIIME2 software were used for sequencing and bioinformatics analysis of the stool specimens.Blood tumor markers CEA,CA-199 and CA72-4 were detected,and Medcalc software was used to draw ROC curve to analyze the diagnostic value of CEA,CA-199 and CA72-4 combined with intestinal flora in the detection of colorectal cancer.Results:1.At the phylum level,Firmicutes,Proteobacteria,Bacteroidota and Actinobacteriota are highly expressed in the intestinal flora,but the composition ratio of the three groups of intestinal flora is different.Proteobacteria(P=0.019)is the characteristic group of adenoma group.2.At the genus level,the abundance of Klebsiella in adenoma group was higher than that in healthy group(P=0.044);The abundance of Prevotella＿9 in adenoma group was lower than that in colorectal cancer group(P=0.004)and healthy group(P<0.01).Megamonas and unclassified Clostridia＿UCG-014＿unclassified were more abundant in colorectal cancer group than in adenoma group(P=0.032,P=0.002).The abundance of Christensenellaceae＿R-7＿group and Ruminococcus in colorectal cancer group was higher than that in healthy group(P=0.0263,P=0.04).Megasphaera(P=0.002,P=0.002),Akkermansia(P<0.01,P<0.01)Eubacterium＿coprostanoligenes＿group＿unclassified(P=0.001,P=0.024),had higher abundance in colorectal cancer group than in adenoma group and healthy group.3.ROC curve results showed that CEA,CA-199 and CA72-4combined with intestinal flora in colorectal cancer detection had higher diagnostic value than CEA,CA-199 and CA72-4 alone(P=0.0395,P=0.0417).Conclusions:1.There were certain differences in the distribution and abundance of intestinal flora among colorectal cancer group,adenoma group and healthy group.The intestinal flora of adenoma group was similar to that of healthy group,but significantly different from that of colorectal cancer group.2.CEA,CA-199 and CA72-4 combined with intestinal flora have certain diagnostic value in colorectal cancer detection.