前列腺癌实验室诊断指标的选择及最佳阈值探讨

目的探讨血清游离前列腺特异性抗原（fPSA）、总前列腺特异性抗原（TPSA）及其比值（f／T）在前列腺癌（PCa）诊断中的应用价值，并应用受试者工作特征（ROC）曲线对其最佳阚值进行确定。方法应用Roche Modular P／E生化、免疫一体机测定48例PCa患者和78例非PCa患者其中良性前列腺增生（BPH）54例，急性尿潴留（24例]血清中TPSA和fPSA水平，同时计算f／T比值，应用ROC曲线进行分析。结果TPSA、fPSA和f／T比值在PCa患者组显著升高。应用ROC曲线分析，确定TPSA、fPSA、f／T的阈值分别为6．58、3．52ng／mL和0．37，阈值处TPSA、fPSA及f／T的灵敏度分别为72．5％、64．6％和54．1％，特异性分别为83．4％、74．0％和60．5％，TPSA、IPSA、f／T分别及联合检测的ROC曲线下面积分别为0．78、0．72、0．69和0．88。结论TPSA、fPSA及f／T可作为PCa的实验室检测指标，三者联合检测可提高对PCa诊断的灵敏度和特异性。

The value of fPSA, TPSA,f/T Ratio and optimal threshold in prostate carcinoma

Objective To explore the value of serum total prostate specific antigen（TPSA）,free prostate specific antigen（fPSA） and f/T ratio in the diagnosis of carcinoma of prostate（PCa）, and to determine the optimal threshold value of these different prostate specific antigens by using ROC curves. Methods The level of TPSA,fPSA and f/T ratio were measured in the 48 cases of PCa,78 cases of non-Pca（54 cases of BPH and 24 cases of AUR ） by Roche Modular P/E automatic Chemistry and immunology instrument. Results The level of TPSA, fPSA and f/T ratio show significant difference between the cases of PCa group and non- PCa group（P〈0.01 ,P〈0. 01 ,P〈0.01）. The optimal threshold value of TPSA, fPSA and f/T ratio are 6.58ng/mL, 3.52ng/mL,0.37 respectively. The ROC curve shows the sensitivity of TPSA, fPSA and all of the three indexes are 72.5 %, 64. 6 %, 84.1% respectively, while the specificity of them is 83.4% ,74.0% ,90.5% respectively. The area under the ROC curve（ACUROC） of TPSA, fPSA , f/T ratio and all of them are 0. 78,0. 72,0. 69 and 0.88 respectively. Conclusion The indexes of TPSA, fPSA and f/T ratio can be used to diagnose the PCa. The combined application of TPPA,fPSA and f/T ratio can improve the sensitivity and the specificity of the diagnosis of prostate cancer.