Okegawa T, Kinjo M, Watanabe K, Noda H, Kato M, Miyata A, Murata A, Yoshii M, Nutahara K, Higashihara E
Department of Urology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
BJU Int. 2000 Apr;85(6):708-14. doi: 10.1046/j.1464-410x.2000.00602.x.
To compare the ratio of free prostate specific antigen (fPSA), total PSA (tPSA) and complexed PSA (cPSA, measured using a novel immunoassay) with other variables used to detect prostate cancer in patients with intermediate serum PSA levels of 4.1-10.0 ng/mL.
From July 1997 to August 1998, 140 consecutive patients were assessed; all had intermediate serum PSA levels and/or abnormal findings on a digital rectal examination. All patients underwent transrectal ultrasonography (TRUS)-guided biopsy, and the prostate and transition zone volumes were determined by TRUS. Free and tPSA were measured using the Tandem-R assay (Hybritech Corp., San Diego, CA). PSA complexed with alpha1-antichymotrypsin (cPSA) was measured using an appropriate assay. The ability of cPSA, free-to-total PSA ratio (f/tPSA), free-to-complexed PSA ratio (f/cPSA), tPSA density of the whole prostate (PSAD), of the transition zone (tPSATZ), and cPSA density of the whole prostate (cPSAD) and of the transition zone (cPSATZ) to improve the power of PSA in detecting prostate cancer was evaluated using receiver operating characteristic (ROC) curves. Results Of the 140 patients, 126 had histologically confirmed benign disease and 14 had prostate cancer. The cPSA alone had better specificity for detecting prostate cancer than had tPSA alone but the difference was not significant. The area under the ROC curve for f/cPSA was larger than those for all other variables. With a 93% sensitivity for detecting prostate cancer, a f/cPSA threshold of 25% would result in fewer unnecessary biopsies (40% f/cPSA specificity) than with all other PSA variables. The difference in the resolution was significant between f/cPSA and tPSA, cPSA, tPSAD and tPSATZ, but not with f/tPSA, cPSAD or cPSATZ. In patients with a prostate volume of < 30 mL, the cPSATZ showed better specificity for prostate cancer than tPSA alone.
Measuring the level of cPSA and its derivatives may provide better differentiation of prostate cancer and benign disease than tPSA alone in patients with a tPSA level of 4.1-10.0 ng/mL.
比较游离前列腺特异性抗原（fPSA）、总前列腺特异性抗原（tPSA）和复合前列腺特异性抗原（cPSA，采用新型免疫测定法测量）与其他用于检测血清PSA水平处于4.1 - 10.0 ng/mL之间的前列腺癌患者的变量的比值。
1997年7月至1998年8月，对140例连续患者进行评估；所有患者血清PSA水平均处于中等范围和/或直肠指检有异常发现。所有患者均接受经直肠超声（TRUS）引导下活检，并通过TRUS测定前列腺和移行区体积。使用Tandem - R测定法（Hybritech公司，加利福尼亚州圣地亚哥）测量游离PSA和tPSA。使用适当的测定法测量与α1 - 抗糜蛋白酶结合的PSA（cPSA）。使用受试者操作特征（ROC）曲线评估cPSA、游离PSA与总PSA比值（f/tPSA）、游离PSA与复合PSA比值（f/cPSA）、整个前列腺的tPSA密度（PSAD）、移行区的tPSA密度（tPSATZ）、整个前列腺的cPSA密度（cPSAD）以及移行区的cPSA密度（cPSATZ）提高PSA检测前列腺癌能力的情况。结果：140例患者中，126例经组织学证实为良性疾病，14例患有前列腺癌。单独的cPSA在检测前列腺癌方面比单独的tPSA具有更好的特异性，但差异不显著。f/cPSA的ROC曲线下面积大于所有其他变量。以25%的f/cPSA阈值检测前列腺癌时，灵敏度为93%，与所有其他PSA变量相比，可减少不必要的活检（f/cPSA特异性为40%）。f/cPSA与tPSA、cPSA、tPSAD和tPSATZ在分辨率上的差异显著，但与f/tPSA、cPSAD或cPSATZ无差异。在前列腺体积<30 mL的患者中，cPSATZ在检测前列腺癌方面比单独的tPSA具有更好的特异性。
在tPSA水平为4.1 - 10.0 ng/mL的患者中，测量cPSA及其衍生物水平可能比单独测量tPSA能更好地区分前列腺癌和良性疾病。
