前列腺特异性抗原（PSA）及其相关参数在PSA灰区诊断前列腺癌的临床研究

The use of prostate- specific antigen （PSA） and correlated indexes in detecting pros- tate cancer in patients with PSA levels of 4 - 10 ng/mL

目的比较前列腺特异性抗原（prostate—specific antigenPSA）及其相关参数如前列腺特异性密度（PSAD）、前列腺移行带抗原密度（PSADtz）、游离前列腺特异性抗原比例（F／TPSA）在PSA为4～10ng／ml水平时鉴别前列腺癌（prostate cancer PCa）的作用。方法分析2004年至2009年2月期间192例血清总PSA浓度在4．0～10．0ngL范围内的前列腺穿刺病人，经直肠超声（TRUS）测定前列腺体积（PV）及内腺体积（TZV），并根据病理结果对PSA及相关指标进行统计学分析。结果占本组病例的15．1％（29／192）。前列腺癌组与良性前列腺增生（benign prostate hyperplasia BPH）组中患者的年龄、tPSA、flea、F／TPSA、差异均无统计学意义（P〉0．05），PCa组PV、PVtz显著小于非癌组，差异有统计学意义（P〈0．01），而PSAD、PSADtz值较BPH组升高（P〈0．01），差异具有显著性。受试者工作特性曲线（receiver operator characteristic curve ROC）曲线下的面积（AUC）从大到小为PSADtz〉PSAD〉tPSA〉F／TPSA，但Aucpsadtz与AUCpsad差异无统计学意义（P〉0．05）。当PSADtz取0．315ng／ml 2为临界值时，其敏感度及特异度分别为88．9％、77．1％。在诊断敏感度均为88．9％的情况下，PSADtz比值诊断特异性高于PSAD的诊断特异性（71．1％ v．s．56．6％）诊断为前列腺癌者29例。结论在本组研究中，当tPSA在诊断灰区时，PSAD和PSADtz对前列腺癌有较好的预测意义，我们推荐PSADtz取0．32ng／ml 2为临界值，以提高前列腺在灰区的断特异度和敏感度。

Objectives This study examined the clinical significance of prostate - specific antigen and correlated indexes such as PSAD, PSADtz, F/TPSA in the differential diagnosis of prostate cancer with an emphasis on patients with total PSA values between 4.0 and 10.0 ng/ml （ the diagnostic gray zone）. Methods We studied continuous 192 cases with serum PSA between 4 - 10ng/ml consecutively from 2004 to February of 2009 and compared the differences of TPSA and PSA correlated variable between these two kinds of diseases. Results There are 29 cases （15.1%） who were diagnosed with prostate cancer. There was no difference in patient age, tPSA, fPSA, and fPSA/tPSA ration level between PCa group and BPH group（ p 〉 0.05 ）, whereas PV and PVtz were significantly smaller than that of BPH（ p 〈 0. 01 ） ; In contrast PSAD and PSADtz level of PCa group were significantly higher than that of BPH group（ p 〈0.05）. The area under ROC curve of three indexes in descending order was PSADtz, PSAD, tPSA and F/TPSA radio. And there was no significant difference in the AUG between PSADtz and PSAD（ p 〉0.05 ）. The sensitivity and specificity of PSADtz at a cutoff value of 0. 315 ng/ml 2 was 88.9% and 71.1%, respectively. To keep sensitivity of 88.9%, the specificity of PSADtz is better than PSAD （71.1% v.s. 56.6% ）. Conclusions In the PSA gray zone, PSAD and PSADtz have better prediction for prostate cancer, and a PSADtz cutoff of 0. 315ng/mL 2 was recommended in our study, which could enhance the sensitivity and specificity of detecting for prostatic cancer.