在总前列腺特异性抗原（total PSA）范围为2.5 - 4.0 ng/ml时，用于早期检测前列腺癌的前列腺特异性抗原原酶：初步分析

Proenzyme psa for the early detection of prostate cancer in the 2.5-4.0 ng/ml total psa range: preliminary analysis.

作者信息

Sokoll Lori J, Chan Daniel W, Mikolajczyk Stephen D, Rittenhouse Harry G, Evans Cindy L, Linton Harry J, Mangold Leslie A, Mohr Phaedre, Bartsch Georg, Klocker Helmut, Horninger Wolfgang, Partin Alan W

机构信息

Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.

出版信息

Urology. 2003 Feb;61(2):274-6. doi: 10.1016/s0090-4295(02)02398-1.

DOI:10.1016/s0090-4295(02)02398-1

PMID:12597929

Abstract

OBJECTIVES

To determine the clinical utility of using proenzyme prostate-specific antigen (pPSA) for early detection of prostate cancer in the 2.5 to 4.0 ng/mL total PSA range. pPSA, the precursor form of PSA that contains a 7 amino acid leader peptide, and truncated forms such as [-2]pPSA and [-4]pPSA can be measured in serum by research immunoassay.

METHODS

Archival serum from 119 men (noncancer, 88; cancer, 31), obtained before biopsy and in the total PSA range of 2.5 to 4.0 ng/mL, were assayed for total PSA, free PSA (fPSA), and pPSA. pPSA was defined as the sum of the [-2], [-4], and [-7] forms, and the percent pPSA (%pPSA) was defined as pPSA/fPSA.

RESULTS

pPSA averaged 4.6% +/- 0.4% (SEM) of total PSA and 39.3% +/- 3.5% of fPSA. PSA and %fPSA values were similar between the noncancer and cancer groups, and %pPSA tended to be higher in the cancer group (50.1% +/- 4.4%) compared with the noncancer group (35.5% +/- 6.7%; P = 0.07). Using receiver operating characteristic analysis to assess clinical utility, the area under the curve for %pPSA was 0.688 compared with 0.567 for %fPSA. At a fixed sensitivity of 75%, the specificity was significantly greater for %pPSA at 59% compared with %fPSA at 33% (P <0.0001).

CONCLUSIONS

In the 2.5 to 4.0 ng/mL total PSA range, 75% of cancers can potentially be detected with 59% of unnecessary biopsies being spared using %pPSA; use of %fPSA would result in sparing only 33% of unnecessary biopsies. A large prospective clinical trial is needed to confirm these preliminary findings.

摘要

目的

确定在总前列腺特异性抗原（PSA）范围为2.5至4.0 ng/mL时，使用前列腺特异性抗原酶原（pPSA）进行前列腺癌早期检测的临床实用性。pPSA是PSA的前体形式，包含一个7个氨基酸的前导肽，其截短形式如[-2]pPSA和[-4]pPSA可通过研究性免疫测定法在血清中进行检测。

方法

对119名男性（非癌症患者88名；癌症患者31名）活检前获取的、总PSA范围为2.5至4.0 ng/mL的存档血清进行总PSA、游离PSA（fPSA）和pPSA检测。pPSA定义为[-2]、[-4]和[-7]形式的总和，pPSA百分比（%pPSA）定义为pPSA/fPSA。

结果

pPSA平均占总PSA的4.6%±0.4%（标准误），占fPSA的39.3%±3.5%。非癌症组和癌症组之间的PSA和%fPSA值相似，癌症组的%pPSA（50.1%±4.4%）相较于非癌症组（35.5%±6.7%；P = 0.07）有升高趋势。使用受试者工作特征分析评估临床实用性，%pPSA的曲线下面积为0.688，而%fPSA为0.567。在固定灵敏度为75%时，%pPSA的特异性显著高于%fPSA，分别为59%和33%（P <0.0001）。