与α1抗糜蛋白酶结合的前列腺特异性抗原（PSA）比例，可提高总PSA为10至30μg/L男性中前列腺癌与良性前列腺增生之间的鉴别能力。

The proportion of prostate-specific antigen (PSA) complexed to alpha(1)-antichymotrypsin improves the discrimination between prostate cancer and benign prostatic hyperplasia in men with a total PSA of 10 to 30 microg/L.

作者信息

Martínez Manuel, España Francisco, Royo Montserrat, Alapont José M, Navarro Silvia, Estellés Amparo, Aznar Justo, Vera César D, Jiménez-Cruz Juan F

机构信息

Department of Urology, Research Center, La Fe University Hospital, 46009 Valencia, Spain.

出版信息

Clin Chem. 2002 Aug;48(8):1251-6.

PMID:12142381

Abstract

BACKGROUND

The aim of this study was to assess the diagnostic accuracy of the proportion of prostate-specific antigen (PSA) complexed to alpha(1)-antichymotrypsin (PSA-alpha(1)ACT:PSA ratio) in the differential diagnosis of prostate cancer (CaP) and benign prostatic hyperplasia (BPH) in men with total PSA of 10-30 microg/L.

METHODS

We used our immunoassays (ELISAs) for total PSA and PSA-alpha(1)ACT complex to study 146 men. In 123, total PSA was between 10 and 20 microg/L; 66 of these had CaP and 57 BPH. In 23 men, total PSA was between 20 and 30 microg/L; 14 of these had CaP and 9 BPH. We calculated the area under the ROC curves (AUC) for total PSA, PSA-alpha(1)ACT complex, and PSA-alpha(1)ACT:PSA ratio, and determined the cutoff points that gave sensitivities approaching 100%.

RESULTS

In the total PSA range between 10 and 20 microg/L, the AUC was significantly higher for the PSA-alpha(1)ACT:PSA ratio (0.850) than for total PSA (0.507) and PSA-alpha(1)ACT complex (0.710; P <0.0001). A cutoff ratio of 0.62 would have permitted diagnosis of all 66 patients with CaP (100% sensitivity) and avoided 19% of unnecessary biopsies (11 of 57 patients). In the total PSA range between 20 and 30 microg/L, the AUC for the PSA-alpha(1)ACT:PSA ratio (0.980; 95% confidence interval, 0.82-0.99) was greater than the AUC for total PSA (0.750; 95% confidence interval, 0.51-0.89; P = 0.042). In this range, a cutoff point of 0.64 would have permitted the correct diagnosis of all 14 patients with CaP and 6 of the 9 with BPH.

CONCLUSIONS

The diagnostic accuracy of the PSA-alpha(1)ACT:PSA ratio persists at high total PSA concentrations, increasing the specificity of total PSA. Prospective studies with large numbers of patients are needed to assess whether the ratio of PSA-alpha(1)ACT to total PSA is a useful tool to avoid unnecessary prostatic biopsy in patients with a total PSA >10 microg/L.

摘要

背景

本研究旨在评估在总前列腺特异性抗原（PSA）水平为10 - 30μg/L的男性中，与α1 - 抗糜蛋白酶结合的PSA比例（PSA - α1ACT:PSA比值）在前列腺癌（CaP）和良性前列腺增生（BPH）鉴别诊断中的诊断准确性。

方法

我们使用针对总PSA和PSA - α1ACT复合物的免疫测定法（酶联免疫吸附测定）对146名男性进行研究。其中123名男性的总PSA在10至20μg/L之间；这些患者中66例患有CaP，57例患有BPH。另外23名男性的总PSA在20至30μg/L之间；其中14例患有CaP，9例患有BPH。我们计算了总PSA、PSA - α1ACT复合物以及PSA - α1ACT:PSA比值的ROC曲线下面积（AUC），并确定了敏感性接近100%的临界值。

结果

在总PSA为10至20μg/L的范围内，PSA - α1ACT:PSA比值的AUC（0.850）显著高于总PSA的AUC（0.507）和PSA - α1ACT复合物的AUC（0.710；P <0.0001）。临界比值为0.62时，可诊断出所有66例CaP患者（敏感性100%），并避免19%的不必要活检（57例患者中的11例）。在总PSA为20至30μg/L的范围内，PSA - α1ACT:PSA比值的AUC（0.980；95%置信区间，0.82 - 0.99）大于总PSA的AUC（0.750；95%置信区间，0.51 - 0.89；P = 0.042）。在此范围内，临界值为0.64时，可正确诊断出所有14例CaP患者以及9例BPH患者中的6例。