Department of Urology, San Raffaele Turro, Vita-Salute San Raffaele University, Milan, Italy.
Eur Urol. 2011 Aug;60(2):214-22. doi: 10.1016/j.eururo.2011.03.052. Epub 2011 Apr 5.
Total prostate-specific antigen (tPSA), ratio of free PSA (fPSA) to tPSA (%fPSA), and PSA density (PSAD) testing have a very low accuracy in the detection of prostate cancer (PCa). There is an urgent need for more accurate biomarkers.
To compare the diagnostic accuracy of PSA isoform p2PSA and its derivatives in determining the presence of PCa at initial biopsy with the accuracy of other predictors in patients with tPSA 2.0-10 ng/ml.
DESIGN, SETTING, AND PARTICIPANTS: We conducted an observational prospective study in a real clinical setting of consecutive men with tPSA 2.0-10 ng/ml and negative digital rectal examination who were scheduled for prostate biopsy at a tertiary academic center.
Outpatient transrectal ultrasound-guided prostate biopsies were performed according to a standardized institutional saturation scheme (18-22 cores).
We determined the diagnostic accuracy of serum tPSA, %fPSA, PSAD, p2PSA, %p2PSA [(p2PSA/fPSA)×100] and the Beckman Coulter Prostate Health Index (phi; [p2PSA/fPSA×√tPSA]).
Overall, 107 of 268 patients (39.9%) were diagnosed with PCa at extended prostate biopsies. Statistically significant differences between patients with and without PCa were observed for age, prostate and transition zone volume, PSAD, %p2PSA, and phi (all p values<0.05). In univariate accuracy analysis, phi and %p2PSA were the most accurate predictors of PCa (area under the curve: 75.6% and 75.7%, respectively), followed by transition zone volume (66%), prostate volume (65%), patient age (63%), PSAD (61%), %fPSA (58%), and tPSA (53%). In multivariate accuracy analyses, both phi (+11%) and %p2PSA (+10%) significantly improved the accuracy of established predictors in determining the presence of PCa at biopsy (p<0.001). Although %p2PSA and phi were significantly associated with Gleason score (Spearman ρ: 0.303 and 0.387, respectively; p ≤ 0.002), they did not improve the prediction of Gleason score ≥7 PCa in multivariable accuracy analyses (p > 0.05).
In patients with a tPSA between 2.0 and 10 ng/ml, %p2PSA and phi are the strongest predictors of PCa at initial extended biopsies and are significantly more accurate than the currently used tests (tPSA, %fPSA, and PSAD) in determining the presence of PCa at biopsy.
总前列腺特异性抗原（tPSA）、游离前列腺特异性抗原（fPSA）与 tPSA 的比值（%fPSA）和前列腺特异性抗原密度（PSAD）检测在前列腺癌（PCa）的检测中准确性非常低。因此，我们迫切需要更准确的生物标志物。
比较 PSA 同工型 p2PSA 及其衍生物在初诊时通过活检确定 PCa 存在的诊断准确性与 tPSA 为 2.0-10ng/ml 患者中其他预测因子的准确性。
设计、设置和参与者：我们在一家三级学术中心进行了一项观察性、前瞻性研究，纳入了 tPSA 为 2.0-10ng/ml 且直肠指检阴性的连续男性患者，这些患者计划进行前列腺活检。
对门诊经直肠超声引导下的前列腺活检，根据标准化的机构饱和度方案（18-22 个核心）进行。
我们确定了血清 tPSA、%fPSA、PSAD、p2PSA、%p2PSA[（p2PSA/fPSA）×100]和贝克曼库尔特前列腺健康指数（phi；[p2PSA/fPSA×√tPSA]）的诊断准确性。
总的来说，在扩大的前列腺活检中，107 例（39.9%）患者被诊断为 PCa。在有和没有 PCa 的患者之间观察到年龄、前列腺和移行区体积、PSAD、%p2PSA 和 phi（所有 p 值<0.05）之间存在统计学显著差异。在单变量准确性分析中，phi 和 %p2PSA 是 PCa 最准确的预测因子（曲线下面积：75.6%和 75.7%），其次是移行区体积（66%）、前列腺体积（65%）、患者年龄（63%）、PSAD（61%）、%fPSA（58%）和 tPSA（53%）。在多变量准确性分析中，phi（+11%）和 %p2PSA（+10%）均显著提高了在活检中确定 PCa 存在的既定预测因子的准确性（p<0.001）。尽管 %p2PSA 和 phi 与 Gleason 评分显著相关（Spearman ρ：0.303 和 0.387，分别；p≤0.002），但它们并不能提高多变量准确性分析中 Gleason 评分≥7 PCa 的预测（p>0.05）。
在 tPSA 为 2.0-10ng/ml 的患者中，%p2PSA 和 phi 是初始扩大活检中 PCa 的最强预测因子，在确定活检中 PCa 的存在方面，其准确性明显优于目前使用的检测方法（tPSA、%fPSA 和 PSAD）。
