血清cPSA对前列腺癌诊断价值的研究

 目的　探讨血清中结合前列腺特异性抗原 (c PSA)在前列腺癌 (PCa)诊断中的临床价值。方法　用磁微粒子免疫化学发光法测定 72例良性前列腺增生 (BPH)患者和 38例PCa患者c PSA、t PSA ,并计算c PSA/t PSA比值。结果　c PSA及c PSA/t PSA比值可有效地区分BPH和PCa(P <0 .0 0 5 ) ,尤其是在诊断灰值区 (t PSA为 4～ 1 0ng/ml)时效果更显著。在以t PSA≤1 0 .0ng/ml和c PSA/t PSA≥0 .72为筛选界值联合对PCa进行筛选时 ,临床概率敏感度为 93.8%。结论　c PSA的引入及c PSA/t PSA比值的应用 ,对PCa的诊断具有重要临床意义 ,尤其是在前列腺特异性抗原的诊断灰值区。     

血清铁蛋白联合前列腺特异性抗原检测对前列腺癌的诊断价值

目的探讨血清铁蛋白(Ferr)、总前列腺特异性抗原(tPSA)、游离前列腺特异性抗原(f PSA)、fPSA/tPSA联合检测对前列腺癌(PCa)的诊断价值。方法选择90例PCa患者、84例前列腺良性病变患者和50例健康男性体检者分别作为PCa组、良性组和对照组,检测3组研究对象的血清Ferr、tPSA、fPSA水平并计算fPSA/tPSA,分析Ferr、tPSA、fPSA、fPSA/tPSA联合检测对PCa的诊断价值。结果PCa组患者的血清Ferr、tPSA、fPSA水平均高于良性组和对照组,fPSA/tPSA低于良性组和对照组,差异均有统计学意义(P﹤0.05)。良性组患者的血清Ferr、tPSA、fPSA水平均高于对照组,fPSA/tPSA低于对照组,差异均有统计学意义(P﹤0.05)。PCa患者的血清Ferr与tPSA、fPSA均呈正相关,tPSA与f PSA呈正相关,tPSA与fPSA/tPSA呈负相关(P﹤0.05)。血清Ferr、tPSA、fPSA、fPSA/tPSA联合检测诊断PCa的灵敏度、特异度、曲线下面积均高于四个指标的三联、两联、单独检测。结论PCa患者的血清Ferr、t PSA、fPSA水平均高于前列腺良性病变患者,fPSA/tPSA低于前列腺良性病变患者。血清Ferr、tPSA、f PSA、f PSA/tPSA联合检测对PCa具有较高的诊断价值,值得在临床中推广应用。     

血清PSA联合PSAD检测对前列腺癌的诊断价值

目的:探讨血清前列腺特异抗原（PSA）、前列腺特异抗原密度（PSAD）对前列腺癌的诊断价值。方法:检测经病理确诊的57例前列腺癌、125例前列腺增生患者的血清PSA。经直肠超声测定其前列腺的体积（PV）并计算PSAD。结果:前列腺癌组患者的PSA、PSAD明显高于前列腺增生组(P<0.05)。PSA值在4.1-10.0,10.1-20.0,>20.0ng/ml区间时PCa诊断率分别为8.8%,36.8%,54.4%。前列腺癌组的ROC曲线图中PSAD的AUC值（0.682）高于PSA的AUC值（0.601）,当取PSAD≥0.18ng/（ml·cm3）时,敏感性为84.5%,特异性为78.6%。比较58例重复穿刺患者的PSA、PSAD,只有PSAD差异有统计学意义(P<0.05)。结论:PSA动态监测结合PSAD是重复穿刺的重要参考指标,PSAD是PSA对前列腺癌诊断的有益补充。     

血清PSA、PSAD、ALP联合检测对前列腺癌骨转移的临床诊断价值

目的 探讨血清前列腺特异性抗原(PSA)、前列腺特异性抗原密度(PSAD)、碱性磷酸酶(ALP)联合检测对前列腺癌(PCa)骨转移的诊断价值.方法 回顾性分析98例PCa患者的临床资料,根据是否发生骨转移分为骨转移组(n=56)和非骨转移组(n=42).检测患者的血清PSA、PSAD、ALP水平,分析3项指标单独及联合检测对PCa骨转移的诊断价值.结果 98例PCa患者中,56例患者发生骨转移,骨转移率为57.1％.骨转移组患者的PSA和PSAD值均高于非骨转移组,差异均有统计学意义(P<0.05).ALP+PSA+PSAD联合诊断PCa骨转移的灵敏度(98.34％)、阳性预测值(90.53％)、阴性预测值(92.33％)及约登指数(73.84)均高于PSA、PSAD、ALP单独诊断的结果.结论 血清PSA、PSAD、ALP联合检测对于PCa骨转移具有较高的诊断价值,值得临床推广应用.     

PSAD和游离/总PSA比值在前列腺癌诊断中的意义

 目的　比较研究前列腺特异抗原(PSA)、PSA密度(PSAD)和游离/总PSA比值(F/TPSA)在前列腺癌诊断中的价值。方法　41例前列腺增生和22例前列腺癌患者,术前用放免法测定血清PSA和游离PSA。所有患者经直肠腔内B超测出前列腺体积,求得PSAD,用t检验比较分析。结果　前列腺癌组的PSA、PSAD均显著高于前列腺增生组(PSA：46.3±33.8μg/Lvs7.04±6.91μg/L,P=0.000021;PSAD：1.43±1.21μg。L-1。ml-1vs0.14±0.15ng。ml-1。ml-1,P=0.000055)。两组的F/TPSA比值无显著差异(0.18±0.11vs0.22±0.18,P=0.34)。结果　PSA和PSAD是鉴别前列腺癌的良好指标,对于PSA可疑者,PSAD有助于区分前列腺癌和前列腺增生,本组游离/总PSA比值不能帮助鉴别诊断。     

游离前列腺特异性抗原与总前列腺特异性抗原比值在前列腺癌鉴别诊断中的应用

 目的 探讨游离前列腺特异性抗原（fPSA）与总前列腺特异性抗原（tPSA）比值在前列腺癌（PCa）鉴别诊断中的意义。方法 采用电化学免疫发光技术对86例前列腺良性增生（BPH）45例PCa患者和60例健康男性体检者（正常对照组）血清fPSA和tPSA同时进行测定，并计算出fPSA／tPSA，进行统计分析。结果 BPH、PCa组tPSA水平明显高于正常对照组（P＜0.05）。PCa组和BPH组的血清tPSA差异亦有统计学意义，但当tPSA在4.0 ~ 10.0 μg／L范围时，PCa组血清fPSA／tPSA比值却明显低于BPH组（P＜0.01）。把fPSA／tPSA比值划分成8个区间，当fPSA／tPSA比值15 ％作为诊断灰区PCa诊断的临界值时，诊断的敏感性、特异性、阳性预测值、阴性预测值及正确诊断指数分别为72.8 %、67.5 %、62.5 %、82.2 %、50.2 %。结论 当血清tPSA处于诊断灰区时，联合检测fPSA／tPSA比值可明显提高tPSA对PCa早期诊断的特异性。     

PSAT 在前列腺穿刺活检中的意义

目的:探讨前列腺移行带特异性抗原密度(PSAT)在前列腺穿刺活检中的意义。方法:对120例患者行前列腺穿刺活检,其中PSA≥4ng/ml者105例,PSA<4ng/ml且直肠指诊及经直肠B超有阳性发现者15例。对PSA、PSAD和PSAT与前列腺穿刺活检的关系进行分析。结果:120例患者中经前列腺穿刺诊断为前列腺癌(PCa)63例,活检阳性率52.5,其中15例PSA<4ng/ml者中,活检结果为前列腺横纹肌肉瘤1例,前列腺小细胞癌2例,腺癌4例,良性前列腺增生8例;42例>20ng/ml者中32例为PCa,活检阳性率76.2;63例PSA4-20ng/ml者中24例为PCa,活检阳性率38.1;29例PSA4-10ng/ml者中10例为PCa,活检阳性率34.5。血清PSA4-20ng/ml患者,PSAD≥0.13或PSAT≥0.15时,敏感性均为100,特异性为20.5或17.9,阳性预测值为43.6或42.9,可避免12.7(8/63)或11.1(7/63)阴性穿刺结果。血清PSA4-20ng/ml时,前列腺穿刺阳性组和阴性组PSA分别为11.18±4.49和10.05±4.29ng/ml(P=0.318);PSAD分别为0.45±0.33和0.26±0.15(P=0.003);PSAT分别为0.94±0.65和0.43±0.24(P=0.000)。血清PSA、PSAD和PSAT的ROC曲线下面积分别为0.576、0.676和0.77,PSAT的ROC曲线下面积与PSA比较,差异均有统计学意义(P<0.05)。结论:PSA4-20ng/ml时,PSAT对预测患者是否行前列腺穿刺活检有较大帮助。     

f/T-PSA比值和PSA密度对TPSA灰区前列腺癌的诊断意义

目的探讨游离前列腺特异抗原/总前列腺特异抗原(fPSA/TPSA,f/T)比值和TPSA灰区前列腺特异抗原密度(PSAD)(4.0~10.0ng/m l)对诊断前列腺癌的临床意义。方法回顾性分析TPSA在灰区的38例前列腺癌和56例良性前列腺增生症血清PSA相关检测结果,将两组患者f/T比值和PSAD值进行对比分析。结果两组患者TPSA值无显著性差异(P=0.337);f/T比值(P=0.001)和PSAD值(P=0.012)有显著性差异。f/T比值在前列腺癌患者中较低,而PSAD值较高。当f/T比值和PSAD分别以0.15和0.16作为临界值时,其诊断前列腺癌的灵敏度和特异度分别为81.6%和75.0%、65.8%和57.1%。结论f/T比值和PSAD对TPSA灰区的前列腺癌的诊断有重要的临床意义。     

PSA、PSAD测定对前列腺癌诊断的价值

目的：探讨血清前列腺特异抗原（PSA）和前列腺特异性抗原密度（PSAD）作为前列腺癌（PC）诊断指标的价值。方法：采用放射免疫分析方法测定50例前列腺增生（BPH）患者36例前列腺癌（PC）患者的血清PSA水平，B超测定前列腺体积，计算单位体积的PSA值（PSAD），结果：PSA界限值定为4μg/L时，其诊断PC敏感度为94％，特异度为36％，准确度为60％，PSA界限值为10μg/L时，敏感度为89％，特异率为62％，准确度为73％，PSAD测定诊断PC敏感度为89％，特异度为90％，准确度为90％，结论：对于前列腺癌的诊断，PSAD值测定较PSA值测定的准确度高。     

3.0T多参数磁共振成像前列腺影像报告和数据系统V2.1评分联合前列腺特异性抗原密度在前列腺癌诊断中的应用

目的探讨3.0T多参数磁共振成像(Mp-MRI)前列腺影像报告和数据系统(PI-RADS)V2.1评分联合前列腺特异性抗原密度(PSAD)在前列腺癌(PCa)诊断中的应用。方法回顾性分析2017年5月至2021年10月南通市第二人民医院收治的82例疑似PCa患者的临床资料。获取所有患者3.0T Mp-MRI PI-RADS V2.1评分、血清PSAD水平、病理诊断结果。比较病理诊断的PCa与前列腺增生(BPH)患者的3.0T Mp-MRI PI-RADS V2.1评分及其分布以及血清PSAD水平。采用受试者工作特征(ROC)曲线, 以病理结果为金标准, 分析3.0T Mp-MRI PI-RADS V2.1评分、血清PSAD水平单独及二者联合对PCa的诊断效能。结果经病理诊断, PCa 43例(52.44%), BPH 39例(47.56%)。PCa与BPH患者3.0T Mp-MRI PI-RADS V2.1评分分布差异有统计学意义(Z=32.25, P<0.001);PCa患者3.0T Mp-MRI PI-RADS V2.1评分高于BPH患者[(4.29±0.25)分比(2.24...     

TPSA、F／T及PSAD在前列腺癌诊断中的意义

目的探讨血清中总前列腺特异性抗原（TPSA）、血清游离PSA（FPSA）与TPSA比值（F／T）及PSA密度（PSAD）在前列腺癌诊断中的意义。方法对50例健康体检男性、467例良性前列腺增生症（BPH）及116例前列腺癌患者TPSA、F／T及PSAD值的差异进行分析、比较。结果血清TPSA值前列腺癌组（53．26±33．10）高于BPH组（8．12±9．70）及对照组（1．51±1．17）;PSAD值前列腺癌组[（1．59±1．46）ng·ml^-1·cm^-3]高于BPH组[（0．14±0．17）ng·ml^-1·cm^-3]及对照组[（0．08±O．07）ng·ml^-1·cm^-3];而F／T值前列腺癌组（0．22±0．16）低于BPH组（0．27±0．15）及对照组（0．36±0．14）,差异均有统计学意义（P值均〈0．01）。PSA处于4～10ng／ml时,前列腺癌组F／T（0．18±0．13）显著低于BPH组（0．27±0．14）（P〈0．05）;前列腺癌组PSAD[（0．21±0．07）ng·ml^-1·cm^-3]显著高于BPH组[（0．11±0．06）ng·ml^-1·cm^-3]（P〈0．001）。取F／T值0．16、PSAD值0．15ng·ml^-1·cm^-3为临界值时,F／T、PSAD值灵敏度、特异度及阳性预测值分别为81．6％、78．2％、96．1％和53．8％、76．9％、97．9％,诊断效率最高。结论F／T、PSAD是诊断前列腺癌的良好指标,当PSA为4-10ng／ml诊断灰区时,F／T与PSAD对诊断前列腺癌有较好的价值。     

PSA,PSAD,fPSA在前列腺癌诊断中的应用

目的：测定１６例前列腺癌（ＰＣａ）和３３例前列腺增生（ＢＰＨ）患者血清前列腺特异性抗原（ＰＳＡ）,前列腺特异抗原密度（ＰＳＡＤ）及游离前列腺特异抗原（ｆＰＳＡ）。方法：采用放射免疫法。结果：显示ＰＳＡＤ对ＰＣａ诊断敏感度高而特异阳性预测值低,而ＰＳＡＤ及ｆＰＳＡ／ｔＰＳＡ比值（即参数百分率）是提高ＰＣａ和ＢＰＨ鉴别诊断阳性率的一种较好指标。结论：本实验结果在实际临床应用中有重要意义。     

Factors influencing the ratio of free to total prostate-specific antigen in serum

The ratio of free prostate-specific antigen (f-PSA) to total PSA (t-PSA) in serum, calculated as percent free PSA (f-PSA%), is lower in patients with prostate carcinoma (PCa) than in patients with benign prostate hyperplasia (BPH). This parameter facilitates discrimination between the 2 groups of patients, but there is an overlapping of data. A better understanding of factors influencing this ratio is of practical importance. Therefore, f-PSA% was measured in controls and patients suffering from BPH, PCa and chronic prostatic inflammation with t-PSA concentrations up to 20 μg/l using the IMMULITE assays. The relationships of f-PSA% to clinical situation, age, prostate volume, kind of treatment, and stage and grade of tumor were calculated. Compared with controls or BPH patients, mean f-PSA% values were reduced in PCa patients and in patients with chronic prostatic inflammation. The prostate volume was the most important factor to influence f-PSA%. The difference of f-PSA% between PCa and BPH patients with prostate volumes smaller than 40 cm³ was lost if the prostate volumes exceeded 40 cm³. No relationship of f-PSA% to pTNM stage or grade of tumor was observed. In contrast to t-PSA concentrations, the f-PSA% values were not age-dependent and were not influenced by any kind of treatment in BPH and PCa patients either, which simplifies the use of f-PSA% compared with t-PSA. Thus, for using f-PSA% in clinical practice and for interpreting the data correctly, the advantages shown have to be considered along with the potential limitations of f-PSA%. Int. J. Cancer 74:630–636.© 1997 Wiley-Liss, Inc.     

Prostate-specific Antigen Velocity (PSAV) and PSAV per Initial Volume (PSAVD) for Early Detection of Prostate Cancer in Chinese Men

Aim: To investigate the utility of prostate-specific antigen velocity (PSAV) and PSAV per initial volume(PSAVD) for early detection of prostate cancer (PCa) in Chinese men. Methods: Between January 2009 andJune 2012, a total of 193 men (aged 49–84 years, median 67 years) with at least 2 transrectal ultrasonography(TRUS) procedures and concurrent serum PSA measurements underwent prostate biopsy because of suspicionof PCa. The total group were classified into PCa and non-PCa groups, and the variables of the two groups werecompared. Univariate and multivariate analyses were used to investigate which variables were predictove. Thediagnostic values of PSAV, PSAVD and prostate-specific antigen density (PSAD) were compared using receiveroperating characteristic (ROC) analysis. Results: Prostate cancer was diagnosed in 44 (22.8%) of the 193 men.There were significant differences between the groups in last and initial prostate volumes determined by TRUS,initial age, last serum PSA levels, PSAV, PSAD and PSAVD. After adjusting for confounding factors, the oddsratios of PCa across the quartile of PSAVD were 1, 4.06, 10.6, and 18.9 (P for trend <0.001).The area under theROC curves (AUCs) of PSAD (0.779) and PSAVD (0.776) were similar and both significantly greater than thatof PSA (AUC 0.667). PSAVD was a significantly better indicator of PCa than PSAV (AUC 0.736). There was nostatistical significant difference between the AUC of PSAV and that of last serum PSA level. The sensitivity andspecificity of PSAVD at a cutoff of 0.023ng in participants with last serum PSA levels of 4.0ng/mL-10.0ng was73.7% and 70.7%, respectively. Conclusions: The results of this study demonstrated PSAVD may be a usefultool in PCa detection, especially in those undergoing previous TRUS examination.     

A higher PSA-density cut-off level in patients with intermediate PSA values for the early detection of prostate cancer

The use of PSA-density (PSAD) as an indicator for prostate biopsy at intermediate PSA values has generated controversy. There are investigators who consider that the determination of PSAD is futile, and that it is better to do a prostate biopsy based on PSA values alone, TRUS (Transrectal Ultrasound) findings and/or DRE examinations. Asian countries, especially in the Far East, are considered to have a low incidence of prostate cancer (PCa). However, based on western references, we still measure PSA-density with a cut-off level of 0.15 to promote prostate biopsy in patients with intermediate PSA values (4.1-10.0 ng/ml). Our study aims to evaluate the usefulness of PSAD as an indication for biopsy in patients with intermediate serum PSA values. To evaluate the usefulness of this indicator, we conducted a retrospective study of 132 uncatheterized (to minimize potential bias) BPH and PCa cases that were hospitalized in our department between 1995-1997 (3 years). This group comprised 127 BPH and 5 PCa patients. Mean age was 66.1 +/- 7.69 years; mean PSA was 7.92 +/- 9.289 ng/ml; mean prostate volume was 54.1 +/- 26.72 cc; mean PSAD was 0.15 +/- 0.185. More specifically, there were 49 patients with intermediate PSA values (47 BPH & 2 PCa). The receiver operator characteristic (ROC) curve revealed an optimum cut-off level of 0.19. At this level of PSA density, the measured sensitivity was 100% with a specificity of 79%. We concluded that, in our uncatheterized patients (without retention) series, the PSAD cut-off level for prostate biopsy (0.19) was higher than that in the western world (0.12 or 0.15).     

ROC曲线分析波谱定量分析在前列腺癌中的诊断价值

目的：探讨MR波谱（magnetic resonance spectroscopy,MRS）定量分析方法在前列腺癌（prostatic carci-noma,PCa）诊断中的意义。方法：对所有疑诊PCa患者行前列腺磁共振波谱分析,酶联免疫法测定血清前列腺特异抗原（PSA）,经直肠超声测定前列腺体积,计算前列腺特异抗原密度（PSAD）,经超声引导下系统穿刺活检证实的71例良性前列腺增生患者和31例PCa患者,分别测量各个位置（胆碱＋肌酸）/枸橼酸盐[（Cho＋Cre）/Cit]的比值,并取均值。结果：前列腺穿刺阳性组的PSA、PSAD及（Cho＋Cre）/Cit的比值分别为23.73±19.06、0.62±0.42、2.33±0.66;前列腺穿刺阴性组的PSA、PSAD及（Cho＋Cre）/Cit的比值分别为8.61±4.47、0.15±0.13、0.73±0.39。阳性组的检测值均较阴性组高（P〈0.05）。PSA、PSAD及（Cho＋Cre）/Cit在ROC曲线下的面积分别为0.71、0.76、0.84。在保持93.5%的敏感性以上时,PSA、PSAD及（Cho＋Cre）/Cit的特异性是43.7%、63.4%和83.1%,（Cho＋Cre）/Cit较PSA、PSAD能更好地检出PCa。结论：MRS分析方法定量评价PCa的代谢改变,有助于PCa的早期诊断,同时结合PSA、PSAD更有助于前列腺癌诊断的特异性。     

Frequency of PSA-mRNA-bearing cells in the peripheral blood of patients after prostate biopsy

Transrectal ultrasound (TRUS) guided prostate biopsy is standard diagnostic procedure for prostate cancer (PCa). However, possibility of dissemination of cancer cells by biopsy is not negligible. To investigate this possibility, we examined prostate specific antigen (PSA)-bearing cells in peripheral blood of the 108 patients before and after prostate biopsy. Peripheral blood samples were obtained from 108 patients with elevated serum PSA (sPSA) levels, who had undergone sextant prostate biopsy using TRUS. The presence of PSA-mRNA bearing cells was examined using the nested RT-PCR method enabling detection of one LNCaP cell diluted in 1 ml of whole blood. Among 108 patients, 62 and 46 were diagnosed with benign prostatic hyperplasia (BPH) and PCa, respectively. PSA-mRNA was detected in 3 PCa cases but in no BPH patients before and after biopsy, and in 16 BPH (25.8%) and in 21 PCa (45.7%) patients only after biopsy (P< 0.01). The patients with positive mRNA before biopsy had higher sPSA (P< 0.001), and those after biopsy had higher sPSA and PSA density (PSAD) levels (P< 0.05). Positive PSA-mRNA cases had more cancer involved biopsy cores than the negative PSA-mRNA cases (P< 0.001). Although further investigations are needed, the present findings suggest that prostate biopsy might scatter prostate cells in the blood stream especially in cases with high sPSA and, thus, might contribute to tumour spreading in the cases of prostate cancer.     

血清BSP水平联合PSADT检测在前列腺癌骨转移早期诊断中的价值

目的探讨骨代谢生化指标骨唾液酸蛋白 ( bone sialoprotein,BSP ) 联合前列腺特异性抗原倍增时间(prostate-specific antigen doubling time,PSADT)检测在前列腺癌骨转移临床诊断中的意义。方法选择 2009年1月-2011年4月我院收治的前列腺癌患者58例,依据诊断分为转移组（28例）和无骨转移组（30例）,取前列腺良性增生患者60例以及60例健康体检人员分别作为增生组和健康对照组。采用视觉模拟疼痛评分( VAS)评价骨痛程度;采用ELISA法检测血清BSP水平;采用电化学免疫发光技术检测血清f-PSA、t-PSA水平,采用倍增公式PSADT=lg(2) [log(PSA2)-log(PSA1)]计算PSADT;采用ROC曲线评价BSP、PSADT及两者联合检测在前列腺癌骨转移诊断中的意义。结果两组患者BSP水平均高于健康对照组和增生组(P<0.05);骨转移组患者血清BSP水平均明显高于无转移组(P<0.05);Pearson’s分析结果显示：前列腺癌骨转移患者的BSP和VAS骨痛评分呈显著正相关（P<0.05）;ROC曲线显示, BSP 诊断骨转移的敏感度和特异性分别为71.12%和72.8%;PSADT诊断骨转移的敏感度和特异性分别为84.15%和82.96%;BSP联合PSADT在前列腺癌骨转移诊断中的敏感度、特异性、AUC面积分别为91.26%,89.54%,0.932。结论BSP可能是前列腺癌骨转移患者的有效诊断指标;BSP和PSADT联合检测能大大提高前列腺癌骨转移的敏感度和准确性,便于前列腺癌骨转移的早期诊断。     

Progression of prostate cancer: diagnostic and prognostic utility of prostate-specific antigen, alpha2-macroglobulin, and their complexes

We previously reported cases of advanced prostate cancer (PCa) in which serum alpha2-macroglobulin (alpha2M) levels were markedly decreased to less than approximately 50 mg/dl whereas serum prostate-specific antigen (PSA) levels were remarkably increased. These cases were not complicated with disseminated intravascular coagulation (DIC). In this study, we measured serum PSA and alpha2M in 108 patients with either benign prostatic hyperplasia (BPH) or PCa to elucidate the relationship between PSA, i.e. the serum protease derived from the prostatic tissue, and alpha2M, i.e. the protease inhibitor that was the most abundantly contained in serum. alpha2M was determined by ELISA, total PSA and PSA-alpha1-antichymotrypsin (PSA-ACT) by EIA, and free-PSA by RIA in 44 patients with untreated BPH and 64 patients with untreated PCa. The ready association of alpha2M and PSA was assessed using Western blotting to identify complexes of the two. Levels of total serum PSA correlated positively with those of PSA-ACT in PCa (r = 0.99, p < 0.001), and both levels increased with advancing stage of disease. In contrast, the serum-free PSA/total PSA ratio (free/total PSA) and alpha2M levels decreased as the disease progressed. However, only the free/total PSA ratio attained significant difference for localized cancer in stage T1,2 versus BPH (p < 0.05). In stage M1b PCa, in which serum PSA levels were very high, there was a negative correlation between the total PSA and alpha2M values (r = -0.57, p < 0.05). In addition, serum alpha2M levels tended to decrease with progression of PCa. Serum total PSA levels correlated tightly with serum PSA-ACT levels. It is suggested that PSA is usually complexed with ACT in the serum. Free/total PSA was useful for differential diagnosis between early cancer and BPH. Levels of serum alpha2M of less than 50 mg/dl in PCa patients may indicate a possibility of bone metastases.