Djavan B, Zlotta A R, Byttebier G, Shariat S, Omar M, Schulman C C, Marberger M
Department of Urology, University Hospital of Vienna, Austria.
J Urol. 1998 Aug;160(2):411-8; discussion 418-9.
We compare the ability of several prostate specific antigen (PSA) parameters, including PSA density of the whole prostate and of the transition zone, percent free PSA and PSA velocity, to enhance the specificity for prostate cancer detection and to reduce unnecessary biopsies in men with serum PSA levels of 4 to 10.0 ng./ml.
This prospective study included 559 consecutive men referred for early prostate detection or lower urinary tract symptoms who had a serum PSA of 4.0 to 10.0 ng./ml. All men underwent prostatic ultrasonography and sextant biopsy with 2 additional transition zone biopsies. Specific biopsies of abnormal findings on digital rectal examination were also performed. In all cases if first biopsies were negative an additional set of biopsies was performed within 6 weeks. The ability of PSA density, PSA transition zone, PSA velocity and percent free PSA to improve the power of PSA in the detection of prostate cancer was evaluated with univariate and multivariate analyses as well as receiver operating characteristics (ROC) curves.
Of 559 patients 342 had histologically confirmed benign prostatic hyperplasia and 217 had prostate cancer. Mean serum PSA, PSA velocity, PSA density and PSA transition zone were statistically higher (p <0.018, p <0.037, p <0.0001 and p <0.0001, respectively) and percent free PSA was statistically lower (p <0.0001) in patients with prostate cancer than in those with benign disease. Multivariate analysis and ROC curves showed that PSA transition zone and percent free PSA were the most powerful and highly significant predictors of prostate cancer. Areas under the ROC curve for PSA transition zone and percent free PSA were 0.827 and 0.778, respectively (p=0.01 McNemar test). Combination of free-to-total PSA with PSA transition zone significantly increased the area under the ROC curve compared to PSA transition zone alone (p=0.020). With a 95% sensitivity for prostate cancer detection a PSA transition zone cutoff of 0.25 ng./ml./cc would result in the lowest number of unnecessary biopsies (47% PSA transition zone specificity) compared to all other PSA parameters. However, total prostate volume (greater than 30 cc in 422 men or less than 30 cc in 137) was an important factor in predicting the statistical performance of PSA transition zone. In fact, PSA transition zone did not outperform free percent PSA in sensitivity and specificity when the entire prostate gland volume was less than 30 cc (p=0.094 McNemar test).
PSA density of the transition zone enhances the specificity of serum PSA for prostate cancer detection in referred patients with a serum PSA of 4.0 to 10.0 ng./ml. compared to other PSA parameters currently available. While PSA transition zone was more effective in prostates greater than 30 cc and percent free PSA was more effective in prostates less than 30 cc, the combination of percent free PSA with PSA transition zone further increased prostate cancer prediction.
我们比较了几种前列腺特异性抗原（PSA）参数，包括整个前列腺和移行区的PSA密度、游离PSA百分比和PSA速率，以提高前列腺癌检测的特异性，并减少血清PSA水平为4至10.0 ng/ml的男性患者不必要的活检。
这项前瞻性研究纳入了559例因早期前列腺检测或下尿路症状而转诊的男性患者，他们的血清PSA为4.0至10.0 ng/ml。所有男性均接受了前列腺超声检查和六分区活检，并额外进行了2次移行区活检。对于直肠指检异常发现也进行了针对性活检。在所有病例中，如果首次活检为阴性，则在6周内进行额外的一组活检。通过单因素和多因素分析以及受试者工作特征（ROC）曲线，评估PSA密度、PSA移行区、PSA速率和游离PSA百分比在提高PSA检测前列腺癌能力方面的作用。
559例患者中，342例经组织学证实为良性前列腺增生，217例患有前列腺癌。前列腺癌患者的平均血清PSA、PSA速率、PSA密度和PSA移行区在统计学上显著更高（分别为p<0.018、p<0.037、p<0.0001和p<0.0001），而游离PSA百分比在统计学上显著更低（p<0.0001）。多因素分析和ROC曲线显示，PSA移行区和游离PSA百分比是前列腺癌最有力且高度显著的预测指标。PSA移行区和游离PSA百分比的ROC曲线下面积分别为0.827和0.778（p=0.01，McNemar检验）。与单独的PSA移行区相比，游离PSA与总PSA的组合显著增加了ROC曲线下面积（p=0.020）。对于前列腺癌检测具有95%的敏感性时，与所有其他PSA参数相比，PSA移行区的临界值为0.25 ng/ml/cc时，不必要活检的数量最少（PSA移行区特异性为47%）。然而，前列腺总体积（422例男性大于30 cc，137例小于30 cc）是预测PSA移行区统计学性能的一个重要因素。事实上，当整个前列腺体积小于30 cc时，PSA移行区在敏感性和特异性方面并不优于游离PSA百分比（p=0.094，McNemar检验）。
与目前可用的其他PSA参数相比，移行区的PSA密度提高了血清PSA检测转诊患者前列腺癌的特异性。虽然PSA移行区在大于30 cc的前列腺中更有效，游离PSA百分比在小于30 cc的前列腺中更有效，但游离PSA百分比与PSA移行区的组合进一步提高了前列腺癌预测能力。
