Yu H J, Chie W C, Hsieh C H, Tsai C C, Lai M K
School of Public Health, National Taiwan University, Taipei, Taiwan, ROC.
J Formos Med Assoc. 1996 Oct;95(10):782-8.
Prostate-specific antigen (PSA) has become the most commonly used marker for the detection of prostatic adenocarcinoma (PCa) in recent years. To understand the clinical value of PSA testing in patients with prostate disease, the preoperative serum PSA values of 562 patients who underwent prostatic surgery from April 1993 to December 1995 were correlated with histologic findings in samples taken during surgery. Histopathologic findings revealed 93 cases of PCa and 469 cases of benign prostatic hyperplasia (BPH). Of the 220 patients with a serum PSA level within the normal range (0-4 ng/mL), PCa was diagnosed in six (2.7%) cases. However, among the 342 patients (61%) who had serum PSA > 4.0 ng/mL, BPH was diagnosed in 225 (75%) patients. With a PSA cutoff value of 4.0 ng/mL, the sensitivity, specificity and positive predictive value of PSA in distinguishing PCa from BPH were 94%, 45% and 25%, respectively. Raising the cutoff value to 10 ng/mL enhanced the specificity (76%) and positive predictive value (42%) with a slight compromise in sensitivity (85%). Of the 469 patients with BPH, 255 (54%) had a serum PSA > 4.0 ng/mL and 107 (24%) had a serum PSA > 10.0 ng/mL. Prostate volume, histologically documented prostatic inflammation and history of urinary retention prior to PSA determination may partly explain the abnormal elevation of serum PSA in patients with BPH. Our data confirmed the sensitivity of PSA in the detection of PCa in a country with a low incidence of PCa. However, a considerable proportion of patients with BPH had elevated serum PSA levels caused by factors unrelated to malignancy. Raising the cutoff value of PSA or employing adjunct parameters derived from PSA determination may be helpful in improving the diagnostic efficacy of PSA.
近年来，前列腺特异性抗原（PSA）已成为检测前列腺腺癌（PCa）最常用的标志物。为了解PSA检测在前列腺疾病患者中的临床价值，对1993年4月至1995年12月期间接受前列腺手术的562例患者的术前血清PSA值与手术中采集样本的组织学结果进行了相关性分析。组织病理学结果显示，93例为PCa，469例为良性前列腺增生（BPH）。在血清PSA水平处于正常范围（0 - 4 ng/mL）的220例患者中，有6例（2.7%）被诊断为PCa。然而，在血清PSA > 4.0 ng/mL的342例患者（61%）中，有225例（75%）被诊断为BPH。以4.0 ng/mL为PSA临界值，PSA区分PCa与BPH的敏感性、特异性和阳性预测值分别为94%、45%和25%。将临界值提高到10 ng/mL可提高特异性（76%）和阳性预测值（42%），但敏感性略有下降（85%）。在469例BPH患者中，255例（54%）血清PSA > 4.0 ng/mL，107例（24%）血清PSA > 10.0 ng/mL。前列腺体积、组织学记录的前列腺炎症以及PSA测定前的尿潴留病史可能部分解释了BPH患者血清PSA异常升高的原因。我们的数据证实了在PCa发病率较低的国家，PSA对PCa检测的敏感性。然而，相当一部分BPH患者的血清PSA水平升高是由与恶性肿瘤无关的因素引起的。提高PSA临界值或采用从PSA测定中得出的辅助参数可能有助于提高PSA的诊断效能。
