The Prevalence Of Colorectal Neoplasms In Patients With Coronary Artery Disease And The Detection Of Intestinal Bacterial Flora In Advanced Adenoma

Background and ObjectiveWith the continuous improvement in people’s living standards and the change of eating habits,the incidence of colorectal cancer(CRC)is increasing in China in rec ent years,especially in large cities.In Shanghai,the incidence of CRC ranks the second most common malignancy,and the number of new cases grows by up to 5% per year now.Approximately 75% of new cases of CRC occur in individuals of average-risk(without family history of CRC).Therefore,to reduce the morbidity of CRC in individuals of average-risk is of great significance.Colorectal adenoma(CRA)is the main precancerous disease of CRC,and nearly 80% of CRC was developed from CRA.Among them,advanced CRA has higher risk of canceration.If CRA meets one of the following three items,it can be diagnosed as advanced CRA: an adenoma with a diameter of more than 10mm;a villous adenoma or mixed adenoma with at least 25% villus;an adenoma with high grade dysplasia.The Asia-Pacific Colorectal Screening(APCS)score established in 2011 is a validated measure that enables risk stratification using elementary clinical information on age,sex,family history of CRC,and smoking.It is a clinical risk score predictive of risk for colorectal advanced neoplasia,and suggests that an asymptomatic subject with a high risk score could be offered colonoscopy screening.Except for family history of CRC in a first-degree relative,the other three indicators are common risk factors related to coronary artery disease(CAD).The new proposed APCS score could be a useful tool to explore the further association between CRC and CAD.On the other hand,recent studies have shown that intestinal flora plays an important role in the development of CRC and CAD.However,there is no intestinal flora data available for advanced CRA until now.MethodsIndividuals with suspected CAD but no CRC-related symptoms were divided into CAD and non-CAD groups by the results of coronary angiography.Colonoscopy was performed in individuals at the high-risk tier based on the APCS score.Body height,weight and waist circumference were measured,and body mass index(BMI)and waist/height ratio were calculated.The level of the intestinal flora was measured by Miseq in individuals of average-risk with advanced adenoma or CRC.ResultsThere were 634 of 1157(54.8%)individuals in the high-risk tier based on APCS score.Among them,81.5% was CAD patients(517/634).The prevalence of both adeno ma(32.1%vs.22.2%,p< 0.05)and advanced adenoma(14.7%vs.8.6%,p< 0.05)were significantly higher in the CAD group than those in the non-CAD group.However,the prevalence of CRC did not differ between the two groups(4.1%vs.2.6%).After 83 individuals with family history of CRC were excluded,only the prevalence of adenoma was still significantly higher in the CAD group tha n that in the non-CAD group(25.5% vs.16.0%,p< 0.01).BMI≥25 was positively correlated with the occurrence of adenoma(odds ratio = 2.133,95% CI: 1.219-3.730,p = 0.008)in CAD patients.Thirty tissue samples from the average-risk individuals were divided into normal colonic mucosa group,advanced CRA group and CRC group according to their pathological diagnosis(10 cases in each group).Compared with the detection results of intestinal flora in normal mucosa of colon,the bacterial flora spectrum in patients with advanced CRA were similar to that in patients with CRC.In the phyla level,the ratio of Proteobacteria increased significantly(P<0.05),whereas the ratio of Bacteroidetes and Firmicutes decreased significantly(P<0.05).In the family level,the ratio of Lachnospiraceae,Bacteroidaceae and Ruminococcaceae decreased significantly in patients with advanced CRA and CRC(P<0.05).However,the ratio of Enterobacteriaceae and Streptococcaceae increased significantly(P<0.05),which were much higher in the right side tha n those in the left side of colon in patients with adva nced CRA and CRC.The change of bacteria spectrum in the genera level was similar with those in the family level.ConclusionsCAD patients at high-risk tier classified by the APCS score still show a remarkable high prevalence of CRA even in the absence of a family history of CRC.The association between the occurrence of CRA and CAD was stronger in overweight(BMI≥25)individuals.The intestinal flora had already significantly changed in patients with advanced CRA,which was similar to those of CRC,and there was no obvious difference between the left and right side colon.