Haese A, Graefen M, Noldus J, Hammerer P, Huland E, Huland H
Department of Urology, University Clinic Eppendorf, Hamburg, Germany.
J Urol. 1997 Dec;158(6):2188-92. doi: 10.1016/s0022-5347(01)68192-8.
We correlated prostatic volume with the ratio of free-to-total prostate specific antigen (PSA) in serum from patients with prostatic cancer or benign prostatic hyperplasia (BPH) to evaluate how prostatic volume influences the ratio.
We evaluated sera from 395 patients (mean age 65 years, range 45 to 88) with prostate cancer (239) or BPH (156) for total PSA, free PSA and ratio of free-to-total PSA. For detection of total and free PSA we used an Immulite free and total PSA assay. Prostatic volume was determined with transrectal ultrasonography. Prostatic volume in BPH and prostate cancer patients was divided into 10 ml. groups, and mean ratio of free-to-total PSA was calculated for each volume group and both diseases. For statistical analysis Mann-Whitney U and Kruskal-Wallis tests were performed in addition to calculation of sensitivity and specificity, and receiver operator curves for prostates 60 ml. or less and greater than 60 ml.
For BPH patients the mean ratio of free-to-total PSA was 14.64 to 25.14% without a close relation to prostatic volume. In prostate cancer patients a proportional increase from 8.45 to 19.37% in the ratio of free-to-total PSA with volume was found. Mann-Whitney U analysis revealed significant differences in prostate cancer versus BPH only in patients with prostates of 60 ml. or smaller (p = 0.0008 to 0.029). No significant differences were seen when prostate cancer and BPH patients with prostates larger than 60 ml. were compared (p = 0.082 to 0.868). Kruskal-Wallis test confirmed independence of the ratio of free-to-total PSA from prostatic volume in BPH patients (p = 0.285) but dependence in prostate cancer patients (p <0.0001). Sensitivity was higher in patients with prostates 60 ml. or smaller (86.72%) than in patients with prostates larger than 60 ml. (66%), and specificity was lower at 45.78 and 56.16%, respectively.
We have shown that the ratio of free-to-total PSA is influenced by prostatic volume in patients with prostate cancer. The ratio of free-to-total PSA provides useful information for differentiate BPH from prostate cancer in patients with small prostates but it is less useful in patients with larger prostates, probably because of the larger proportion of benign hypertrophic tissue.
我们将前列腺癌或良性前列腺增生（BPH）患者血清中游离前列腺特异性抗原（PSA）与总PSA的比值与前列腺体积进行关联分析，以评估前列腺体积如何影响该比值。
我们评估了395例患者（平均年龄65岁，范围45至88岁）的血清，其中前列腺癌患者239例，BPH患者156例，检测总PSA、游离PSA以及游离PSA与总PSA的比值。我们使用免疫发光法检测总PSA和游离PSA。通过经直肠超声测定前列腺体积。将BPH和前列腺癌患者的前列腺体积分为10ml一组，计算每个体积组以及两种疾病的游离PSA与总PSA的平均比值。除计算敏感性和特异性外，还进行了Mann-Whitney U检验和Kruskal-Wallis检验，并绘制了前列腺体积60ml及以下和大于60ml患者的受试者操作特征曲线。
对于BPH患者，游离PSA与总PSA的平均比值为14.64%至25.14%，与前列腺体积无密切关系。在前列腺癌患者中，游离PSA与总PSA的比值随体积呈比例增加，从8.45%增至19.37%。Mann-Whitney U分析显示，仅在前列腺体积为60ml及以下的患者中，前列腺癌与BPH之间存在显著差异（p = 0.0008至0.029）。比较前列腺体积大于60ml的前列腺癌和BPH患者时，未发现显著差异（p = 0.082至0.868）。Kruskal-Wallis检验证实，BPH患者游离PSA与总PSA的比值与前列腺体积无关（p = 0.285），而在前列腺癌患者中则相关（p <0.0001）。前列腺体积60ml及以下患者的敏感性（86.72%）高于前列腺体积大于60ml的患者（66%），特异性分别为45.78%和56.16%，较低。
我们已表明，前列腺癌患者中游离PSA与总PSA的比值受前列腺体积影响。游离PSA与总PSA的比值为鉴别小前列腺患者的BPH和前列腺癌提供了有用信息，但对于大前列腺患者用处较小，可能是因为良性增生组织比例较大。
