The Study Of Correlation Among Endoscopic Ultrasonography Findings,Risk Stratification And Ki-67 Index In Gastrointestinal Stromal Tumor

Objective:This study explored the correlation among endoscopic ultrasound(EUS)characteristics of gastrointestinal stromal tumor(GIST),the risk stratification and Ki-67index,the correlation between Ki-67 index and clinical pathological characteristics to illustrate the clinical value of EUS features and Ki-67 index in predicting the malignancy of GIST.Methods:This study included 209 patients from June 2012 to November 2021 in the Affiliated Hospital of Qingdao University.All of them accepted the EUS examination and were diagnosed as GIST.We collected the clinical features,pathological data and EUS features of all patients.SPSS software(version 22.0,IBM)was used for data analysis.T-test,Mann-Whitney-U test,X2or Fisher’s exact method analysis the difference between groups.The correlation among EUS features,risk stratification and Ki-67 index was performed by Spearman’s rank correlation coefficient analysis.Binary logistic regression analysis screened out the EUS signs that can independently affect the expression of Ki-67 and risk stratification.R software was used to build a nomogram model for predicting Ki-67 index,and the receiver operating characteristic(ROC)curve and correction curve were used to evaluate the efficacy of Nomogram Model.Results:1.Tumor diameter(W=-4.730,P=0.000),cystic change(X2=4.270,P=0.039),calci-fication(X2=7.440,P=0.006),and surface ulceration(X2=10.817,P=0.001)of GIST have statistically differences in the lower-risk group and higher-risk group.Growth mode,heterogeneity,boundary,mucosal bridge,layer of origin and echo mode have no statistical significance in two groups(P>0.05).2.The binary logistic regression analysis reveals that tumor size(OR=1.069,95%CI=1.032-1.108,P=0.000)and calcification(OR=0.198,95%CI=0.059-0.657,P=0.008)are the independent risk factors for predicting the degree of malignancy.The area of ROC curve of tumor diameter is 0.760(95%CI=0.668-0.851).The area of ROC curve of tumor diameter combined with calcification signs is 0.806(95%CI=0.729-0.883).3.The mitotic index(X~2=12.654,P<0.001),tumor size(W=-4.750,P<0.001)and risk stratification(X~2=35.679,P<0.001)show significant statistical differences between Ki-67index≤5%group and Ki-67 index>5%group.The Ki-67 index are positively associated with mitotic index,tumor size and risk stratification(r=0.267,0.329 and 0.345).4.EUS signs such as cystic change(X~2=16.438,P<0.001)and surface ulceration(X~2=14.417,P<0.001)have significant difference between Ki-67 index≤5%group and Ki-67 index>5%group.The Ki-67 index are positively associated with cystic change,surface ulceration(r=0.280 and 0.271).The mode of growth,heterogeneity,location,mucosal bridge,calcification,layer of origin,boundary and echo pattern do not reach statistical differences(P>0.05).5.The binary logistic regression analysis reveals that tumor size(OR=1.053,95%CI=1.018-1.091,P=0.003),surface ulceration(OR=2.693,95%CI=1.073-6.270,P=0.035)and cystic change(OR=2.529,95%CI=1.073-6.270,P=0.045)are the effective variables to discriminate Ki-67 index.Tumor diameter combined with cystic change,surface ulceration has good performance in predicting Ki-67 index.6.The area under the ROC curve of the Nomogram model was 0.796(95%CI=0.716-0.875).The calibration curve of the nomogram model is closer to the ideal curve.7.Ki-67 index has difference between small GIST group and larger GIST group(X~2=4.160,P=0.041).Ki-67 index(X~2=16.698,P=0.001),cystic change(X~2=9.644,P=0.015)and surface ulceration(X~2=12.299,P=0.006)have significant differences in the risk stratification of small GIST.Conclusion:As the level of Ki-67 expression in GIST increase,the risk stratification of tumor are higher.Ki-67 index could be an effective supplement to the modified NIH stratification criteria.EUS signs is significant to predicting the risk stratification and Ki-67 index of GIST in preoperative.The nomogram model based on tumor size,cystic change and surface ulceration has good accuracy and consistency in predicting the expression level of Ki-67,providing a convenient tool for clinical observation.