Parsons J Kellogg, Brawer Michael K, Cheli Carol D, Partin Alan W, Djavan Robert
The James Buchanan Brady Urological Institute, The Johns Hopkins Medical Institutions Baltimore, MD 21287, USA.
BJU Int. 2004 Jul;94(1):47-50. doi: 10.1111/j.1464-410X.2004.04899.x.
To compare the performance of complexed prostate-specific antigen (cPSA) to total PSA (tPSA) and percentage free PSA (f/tPSA) in the diagnosis of prostate cancer for the tPSA range 2.6-4.0 ng/mL.
Consecutive men scheduled for prostate biopsy were enrolled prospectively at 14 different sites in two multicentre studies in Europe and the USA. Serum obtained before biopsy was tested with the ACS:180 and Immuno 1 tPSA and cPSA assays (Bayer Diagnostics, Tarrytown, NY, USA) and the Access fPSA and tPSA assays (Beckman, Inc., San Diego, CA, USA). Receiver operating characteristics (ROC) curves were generated to compare the diagnostic performance of tPSA, cPSA and f/tPSA.
Of 316 men with a tPSA of 2.6-4.0 ng/mL, 82 (26%) were diagnosed with prostate cancer on biopsy. ROC analysis of all 316 men showed an area under the curve (AUC) for cPSA of 0.63, significantly greater than the AUC for tPSA of 0.56 (P = 0.008). At a sensitivity of 95%, threshold values of 2.3 ng/mL for cPSA and 2.73 ng/mL for tPSA provided specificities of 20.1% and 9.8%, respectively. f/tPSA was only available for 205 of the 316 (65%) men and the AUC for cPSA was 0.63, and did not significantly differ from the f/tPSA AUC of 0.64 (P = 0.58).
As a single test, cPSA provides improved specificity over tPSA and comparable specificity to f/tPSA for detecting prostate cancer, and may reduce the number of unnecessary prostate biopsies in the 2.6-4.0 ng/mL tPSA range.
比较复合前列腺特异性抗原（cPSA）与总前列腺特异性抗原（tPSA）以及游离前列腺特异性抗原百分比（f/tPSA）在总前列腺特异性抗原水平为2.6 - 4.0 ng/mL时对前列腺癌的诊断性能。
在欧洲和美国的两项多中心研究中，于14个不同地点前瞻性纳入计划进行前列腺活检的连续男性患者。活检前采集的血清采用ACS:180和Immuno 1总前列腺特异性抗原及复合前列腺特异性抗原检测法（美国纽约塔里敦的拜耳诊断公司）以及Access游离前列腺特异性抗原和总前列腺特异性抗原检测法（美国加利福尼亚州圣地亚哥的贝克曼公司）进行检测。绘制受试者工作特征（ROC）曲线以比较总前列腺特异性抗原、复合前列腺特异性抗原和游离前列腺特异性抗原百分比的诊断性能。
在316名总前列腺特异性抗原水平为2.6 - 4.0 ng/mL的男性中，82名（26%）经活检诊断为前列腺癌。对所有316名男性进行的ROC分析显示，复合前列腺特异性抗原的曲线下面积（AUC）为0.63，显著大于总前列腺特异性抗原的曲线下面积0.56（P = 0.008）。在敏感度为95%时，复合前列腺特异性抗原的阈值为2.3 ng/mL，总前列腺特异性抗原的阈值为2.73 ng/mL，其特异性分别为20.1%和9.8%。在316名男性中，仅有205名（65%）可检测游离前列腺特异性抗原百分比，复合前列腺特异性抗原的曲线下面积为0.63，与游离前列腺特异性抗原百分比的曲线下面积0.64无显著差异（P = 0.58）。
作为单一检测指标，在检测前列腺癌方面，复合前列腺特异性抗原比总前列腺特异性抗原具有更高的特异性，与游离前列腺特异性抗原百分比的特异性相当，并且可能减少总前列腺特异性抗原水平在2.6 - 4.0 ng/mL范围内不必要的前列腺活检数量。
