Díaz F, Morell M, Rojo G
Biochemistry Section, Faculty of Medicine, Málaga University, Spain.
Arch Esp Urol. 1997 May;50(4):415-8.
To evaluate the efficiency of PSA excess in distinguishing prostate cancer (PC) in its early stages from benign prostatic hypertrophy (BPH) and compare it with the efficiency of serum PSA.
A cross-sectional study was carried out on 27 patients with PC and 46 with BPH, whose serum PSA and prostatic volume were determined. PSA excess was calculated as the difference between serum PSA and predicted PSA according to the gland volume, calculating the latter as the prostatic volume multiplied by factor 0.3 ng/ml/g.
PSA excess values were significantly higher in patients with PC, while serum PSA levels were not different between the two populations studied. Receiver operating curves (ROC plots) showed a higher diagnostic utility for PSA excess, with a maximum efficiency of 73% at a cut-off point of -13 ng/ml. The predictive value of a positive result is slightly higher for serum PSA, but PSA excess showed a predictive value of a negative result superior to that of PSA.
评估前列腺特异抗原（PSA）过量在早期鉴别前列腺癌（PC）与良性前列腺增生（BPH）中的效率，并将其与血清PSA的效率进行比较。
对27例PC患者和46例BPH患者进行了横断面研究，测定了他们的血清PSA和前列腺体积。PSA过量定义为血清PSA与根据腺体体积预测的PSA之间的差值，后者通过前列腺体积乘以0.3 ng/ml/g的系数计算得出。
PC患者的PSA过量值显著更高，而在所研究的两个人群中血清PSA水平并无差异。受试者工作特征曲线（ROC曲线）显示PSA过量具有更高的诊断效用，在截断点为-13 ng/ml时最大效率为73%。血清PSA阳性结果的预测价值略高，但PSA过量阴性结果的预测价值优于PSA。
