血清t-PSA及f-PSA/t-PSA联合诊断前列腺癌的价值评价

Evaluation of the diagnostic value of serum t-PSA combined with f-PSA/t-PSA in patients with prostate cancer

目的应用logistic回归模型结合多指标联合诊断试验ROC分析评价血清t-PSA及f-PSA/t-PSA在前列腺癌诊断及联合诊断中的效果。方法采用酶联免疫荧光法对56例前列腺癌和80例良性前列腺增生患者进行血清t-PSA和f-PSA检测。分析ROC曲线,确定两项指标最佳诊断值及其灵敏度、特异度。采用Logistic回归建立预测概率模型,获得新的统计量,计算各曲线下面积(AUC),获得最佳诊断点。结果 t-PSA和f-PSA/t-PSA比值对前列腺癌具有最佳诊断价值的切点分别为7.69 ng/mL,0.165,AUC分别为0.784和0.817,二者联合检测AUC为0.868。结论 t-PSA和f-PSA/t-PSA比值的联合诊断有效的提高了前列腺癌的诊断率,ROC曲线结合logistic回归模型简单有效,适用于多指标联合诊断试验的分析评价。

[ Objective ] To explore the application of logistic model in ROC analysis, and to evaluate the clinical value and discriminatory power of total prostate-specific antigen （t-PSA） and free prostate-specific antigen （f-PSA） in prostate cancer. [Methods] t-PSA and f-PSA levels were measured in 56 patients with prostate cancer and 80 patients with benign prostatic hyperplasia （BPH） with enzyme-linked fluorescent assay （ELFA）. Sensitivity, specificity were calculated for each test. Receiver-operating characteristic curves （ROC） were analyzed. Based on the binary logistic regression model, the predictors or probabilities were obtained and applied to establish the empirical and binormal model of the ROC curves to compare the area under the curve （AUC）. [ Results ] The confirmed limitation with the best diagnostic value of the t-PSA and f-PSA/t-PSA in prostate cancer were 7.69 ng/mL and 0.165 respectively, the AUC of which were 0.784 and 0.817 respectively. The combined predicted ROC AUC was 0.868. [Conclusion ] Combined measurement of t-PSA and f-PSA/t-PSA can improve the diagnostic accuracy of prostate cancer efficiently, ROC analysis combined with the logistic model is simple and useful, especially forthe screening test with multiple markers for classification.