Analysis Of Risk Factors And Establishment Of Prediction Model For Recurrence Of Colorectal Adenoma After Resection By Colonoscopy

Background and objectiveWith the increasing popularity of screening for colorectal cancer at early stage in our country,the detection rate of colorectal adenomas has been increasing.However,recurrence of colorectal adenomas are easy to appear and even develop into cancer after endoscopic resection,it is of vital significance to identify risk factors affecting recurrence and assess the recurrent risk to guide the follow-up interval and improve the prognosis of patients.This study aimed to collect and analyze the recurrence of colorectal adenoma after endoscopic resection,and investigate the risk factors associated with the recurrence,building a Logistic regression prediction model and risk score,so as to provide theoretical reference for endoscopists in clinical work.MethodsA retrospective study was adopted.A total of 304 adult in patients who underwent fist endoscopic resection of colorectal adenoma were enrolled in this study,and all of them have endoscopic review records more than six months after resection.The clinical case data(including the demographic and endoscopic parameters,pathological features.)were collected through the electronic medical record database,in addition,some of the missing information were acquired by phone.Patients were divided into the recurrence group and non-recurrence group according to the recurrence within 5 years after endoscopic resection.The Chi-square test was used by the univariate analysis,the independent risk factors for recurrence were identified in the multivariate binary regression analysis.Scores were assigned based on the ratio of the β-coefficients of each independent risk factor to the minimum β-coefficients.The logistic regression prediction model was established and its predictive ability was evaluated using the receiver operating characteristic curve(ROC),it included some indictors such as the area under curve(AUC),sensitivity and specificity.Finally,the risk score was made according to their points based on the correspondingβ-coefficients in order that evaluate the risk grade for recurrence in patients.Results1.In this study,a total of 304 patients were enrolled,208 males and 96 females,their average age was 59.7 ± 11.5 years.All patients underwent different follow-up intervals ranging from 7 to 59 months,with an average follow-up interval of 28.6±15.1 months.During the follow-up period,132 patients recurred for adenoma,the recurrence rate was 43.4%.There were 2 patients who occurred malignant change(1.5%),as colonic hepatic adenocarcinoma and transverse colon adenocarcinoma was respectively found during the follow-up of 8th and 11th months.2.The results of univariate analysis found that patients age,history of hypertension,adenoma diameter,number,location,pathological type and tissue grade were statistically significant differences between the recurrence group and non-recurrence group(P<0.05).However,they have no statistical differences in BMI,gender,family history of colorectal cancer,history of smoking or drinking,diabetes,gastric polyps,dyslipidemia,chronic obstructive pulmonary disease and history of antibiotics or PPIs3.Multivariate Logistic regression analysis showed that patients age ≥50 years(OR=3.177,95%CI 1.475～6.844,P=0.003),the diameter of adenoma≥1.0cm(OR=2.317,95%CI 1.290～4.162,P=0.005),the adenoma number(≥3)(OR=1.792,95%CI 1.036～3.098,P=0.037),located in the left colon(OR=2.975,95%CI 1.695～5.219,P<0.001),villous tubular adenomas(OR=3.642,95%CI 1.473～9.008,P=0.005)and high-grade dysplasia(OR=2.479,95%CI 1.304～4.715,P=0.006)were independent risk factors for recurrence after colorectal adenoma resection by colonoscopy4.The logistic regression prediction model was built according to the above analyzed results,p=ex/(1+ex),e refers to the base of natural logarithms,x=-3.067+1.156×age+0.840×the adenoma diameter+0.583×the adenoma number+1.090× location+1.293×pathological type+0.908× tissue grade,it was able to calculate recurrent probability.Additionally,the area under the ROC curve was 0.776,(95%CI 0.725～0.821),the cut-off value was 0.555,the sensitivity,specificity were 55.30%,87.21%respectively,and the accuracy of this model for predicting was 71.25%5.A risk score based on points in logistic regression model was made,it constituted with six independent risk factors whose their cumulative score of 0 to 10,low risk was defined as score 0～1,moderate risk was defined as score 6～8,high risk was defined as score 9～10.Conclusion1.Patient age,history of hypertension,adenoma diameter,number,location,pathological type and tissue grade are associated with recurrence after colorectal adenoma resection by colonoscopy.Among them,patients age≥50 years,the diameter of adenoma≥1.0cm,the adenoma number(≥3),located in the left colon,villous tubular adenoma and high-grade dysplasia are independent risk factors for recurrence2.The prediction model could be applied to calculate the probability of recurrence after endoscopic resection,it can reach a high predictive level,and the risk score could also be used to evaluate risk grade for recurrence.