The Preliminary Study Of Logistic Regression And ROC Curve In Analysising Multiple Tumor Markers In Differential Diagnosis Of Benign And Malignant Ascites

Objective: To analyze the tumor markers(CEA、CA125、CA19-9、 AFP)in benign and malignant ascites in order to obtain the sensitivity and specificity as well as the critical value for the differential diagnosis of benign and malignant ascites,and to establish a mathematical model of Logistic regression with CEA、CA125 、 CA19-9 joint detection to provide assistance for the differential diagnosis of benign and malignant ascites.Methods: We collected 174 patients with ascites from December 2015 to January 2018 in our hospital.Among them,86 patients with ascites(malignant ascites)diagnosed as malignant tumors were experimental group,and ascites of patients with non-malignant tumors(The benign ascites(88 cases)was the control group,and the ascites was taken for cytological examination and the detection of tumor markers CEA、CA125、CA19-9、AFP.The sensitivity of cytology test=true positive/(true positive+false negative)*100%,specificity=true negative/(true negative+false positive)*100%,positive likelihood ratio=sensitivity/(1-specificity)Degree)and negative likelihood ratio =(1-sensitivity)/specificity.The sensitivity,specificity and critical value of tumor markers(CEA、CA125、CA19-9、AFP)were analyzed by receiver operator characteristic curve(ROC).A mathematical model for the differential diagnosis of benign and malignant ascites was established by using logis(P)=b+a X1+c X2+d X3...+n Xn-1 for the combined detection of CEA,CA125 and CA19-9.Results: Of the 86 patients with malignant ascites,cytology tests showed that 24 cases of ascites cytology were positive,20 cases were indeterminate,42 cases were negative,88 cases of positive ascitic cytology test were positive,0 cases were negative,and 88 cases were negative.The sensitivity of ascitic cytology diagnosis was 24.4%,and the diagnostic specificity was 100%.The tumor markers of malignant ascites were CEA(132.5±47.8)ng/ml,CA199(120.5±47.8)U/ml,CA125(220.5±77.8)U/ml,AFP(176.4±54.5)ng/ml,and tumor markers CEA in 88 cases of benign ascites(4.8±2.6)ng/ml.CA199(26.4±6.8)U/ml,CA125(34.2±10.3)U/ml,and AFP(50.6±17.8)ng/ml were significantly higher than benign tumor markers in malignant ascites.The tumor markers in malignant ascites were significantly higher than those in benign lesions,and were statistically significant by independent samples Mann-Whitney U test(U=32.56,U=71.35,U=46.23,U=34.26,P<0.01),with statistical significance.The diagnostic performance of four tumor markers alone in malignant ascites was evaluated,and a ROC curve was drawn.The cutoff value of CEA in ascites was 6.8 ng/ml,the AUC was 0.867,the sensitivity was 72.0%,and the specificity was 88.1%.The cutoff value of CA199 in ascites was 34.6 U/ml,AUC was 0.812,sensitivity was 71.5%,and specificity was 83.1%.The cutoff value of CA125 in ascites was 39.5 U/ml,AUC was 0.800,sensitivity was 68.0%,and specificity was 71.2%.The cutoff value of AFP in ascites was 68.5 ng/ml,AUC: 0.570,sensitivity: 58.2%,and specificity: 68.2%.The AFP of AFP is 0.570.Combined detection using the parallel experimental detection of CEA + CA199 + CA125 three joint detection of the best,the sensitivity of 82.6%,a specificity of 92.8%,about 0.774 of the index,the coincidence rate of 86.9%,the positive likelihood ratio of 11.47 The negative likelihood ratio is 0.19.Using logistic regression analysis,the regression equation Y=logis(P)=-8.474+0.106XCEA+0.069XCA199+0.047XCA125 was obtained and the regression analysis model pre-test(ie,CEA,CA199,CA125 combined detection)was used as a new variable and CEA、CA199 and CA125 were used together for ROC curve analysis and comparison of diagnostic values.The new variable P after fitting had a cutoff value of 0.0325 at the largest possible index,sensitivity was 85.0%,specificity was 94.0%,and the Yoden index was 0.79.The AUC of the variable P is 0.951.conclusion: 1.The critical values of CEA、CA125、CA19-9 and AFP in ascites determined by chemiluminescent luminescent immunoassay were 6.8 ng/ml、39.5 U/ml、34.6 U/ml and 68.5 ng/ml,respectively.2.The identification of CEA、CA125 and CA19-9 in ascitic fluid using chemiluminescent luminescent immunological Logisitc regression analysis is of great significance in distinguishing between benign and malignant ascites.