Jung K, Meyer A, Lein M, Rudolph B, Schnorr D, Loening S A
Department of Urology, University Hospital Charité, Humboldt University Berlin, Germany.
J Urol. 1998 May;159(5):1595-8. doi: 10.1097/00005392-199805000-00050.
We demonstrate the effect of chronic inflammation of the prostate on the ratio of free-to-total prostate specific antigen (PSA) in serum calculated as a percentage of free PSA and, therefore, that percentage of free PSA is an unspecific means to distinguish among prostate cancer, chronic prostatitis and benign prostatic hyperplasia (BPH).
Total, free and percentage of free PSA was measured in 66 men with prostate cancer, 119 with BPH and 17 with asymptomatic chronic prostatitis. In all patients the diagnosis was histopathologically confirmed by microscopic examination of prostatic specimens after sextant biopsy, transurethral prostatic resection or prostatectomy.
The median values of total, free and percentage of free PSA were 4.11 microg./l., 0.75 microg./l. and 20.4% in patients with BPH, 10.0 microg./l., 0.84 microg./l. and 8.5% in those with prostate cancer, and 7.60 microg./l., 1.23 microg./l. and 10.6% in those with chronic prostatitis. Patients with prostate cancer and chronic prostatitis had a significantly lower percentage of free PSA than those with BPH. Receiver operating characteristics curve analysis showed that percentage of free PSA as a discriminator between prostate cancer and BPH was not suitable for differentiating between prostate cancer and chronic prostatitis.
Chronic prostatitis is not characterized by elevated total PSA concentrations alone but also by a decreased percentage of free PSA, a tendency similar to that in prostate cancer. This unspecific change in percentage of free PSA must be considered to interpret the percentage of free PSA correctly.
我们证明了前列腺慢性炎症对血清中游离前列腺特异性抗原（PSA）与总PSA比值（以游离PSA的百分比计算）的影响，因此，游离PSA的百分比是区分前列腺癌、慢性前列腺炎和良性前列腺增生（BPH）的非特异性方法。
对66例前列腺癌患者、119例BPH患者和17例无症状慢性前列腺炎患者测定了总PSA、游离PSA及游离PSA百分比。所有患者均经六分区活检、经尿道前列腺切除术或前列腺切除术后前列腺标本的显微镜检查进行组织病理学确诊。
BPH患者总PSA、游离PSA及游离PSA百分比的中位数分别为4.11μg/l、0.75μg/l和20.4%；前列腺癌患者分别为10.0μg/l、0.84μg/l和8.5%；慢性前列腺炎患者分别为7.60μg/l、1.23μg/l和10.6%。前列腺癌和慢性前列腺炎患者的游离PSA百分比明显低于BPH患者。受试者工作特征曲线分析表明，游离PSA百分比作为前列腺癌和BPH的鉴别指标，不适用于区分前列腺癌和慢性前列腺炎。
慢性前列腺炎的特征不仅在于总PSA浓度升高，还在于游离PSA百分比降低，这一趋势与前列腺癌相似。在正确解释游离PSA百分比时，必须考虑游离PSA百分比的这种非特异性变化。
