前列腺特异抗原对前列腺癌诊断和疗效监测的价值探讨

目的 探讨前列腺特异抗原(tPSA)、游离PSA(fPSA)以及fPSA/tPSA在前列腺癌(PCa)诊断和疗效监测中的临床价值。方法 采用全自动化学发光免疫分析仪测定36例正常人、42例前列腺增生(BPH)和44例前列腺癌患者tPSA、fPSA,并计算fPSA/tPSA比值。同时,对29例前列腺癌患者术后tPSA、fPSA进行动态监测。结果 fPSA/tPSA对PCa诊断的特异性为88.1％,诊断指数为0.79,显著高于单独tPSA(P<0.05)。结论 fPSA/tPSA的引入提高了对PCa诊断的特异性,动态监测是提示肿瘤是否转移与复发最理想的指标。     

ALP、PSA及其相关指标与前列腺癌骨转移的关系

目的 探讨ALP、PSA及其相关指标(fPSA、fPSA/tPSA、PSAD)与前列腺癌骨转移的关系,及对前列腺癌骨转移诊断的预测作用.方法 回顾分析2005年9月至2009年2月在我院经前列腺穿刺活检或手术后病理检查确诊的167例前列腺癌患者.以ECT、X线片、CT/MRI或骨活检诊断骨转移,分析ALP、PSA、fPSA、fPSA/tPSA、PSAD与前列腺癌骨转移的关系及对骨转移的诊断价值.结果 167例前列腺癌患者中骨转移104例(62.3%),非骨转移63例(37.7%).骨转移组ALP、PSA及PSAD明显高于非骨转移组(均P<0.01),而两组间fPSA/tPSA差异无统计学意义(P>0.05).PSA>50 ng/ml组骨转移率明显高于PSA>20～50 ng/ml组、>10～20 ng/ml组和≤10 ng/ml组(均P<0.05);ALP>90 U/L组骨转移率明显高于ALP≤90 U/L组(P<0.05);PSAD>0.4 ng·ml-1·cm-3组骨转移率明显高于PSAD≤0.4 ng·ml-1·cm-3组(P<0.05).以ALP>90 U/L、PSA>50 ng/ml和PSAD>0.4 ng·ml-1·cm-3为界分别分析ALP、PSA、PSAD、PSA+ALP、PSA+PSAD和PSA+PSAD+ALP对前列腺癌骨转移诊断的预测价值,发现指标联合应用后阳性预测值及阴性预测值较单一指标好,PSA+PSAD+ALP联合应用的敏感度、特异度、阳性预测值及阴性预测值最佳,分别为100%、79.17%、91.38%及100%.结论 ALP、PSA及PSAD均为判断前列腺癌患者有无骨转移的可靠指标,PSA+PSAD+ALP联合应用有助于预测前列腺癌骨转移,当患者PSA<50 ng/ml、PSAD<0.4 ng·ml-1·cm-3及ALP<90 U/L时,几乎可排除骨转移.     

前列腺腺癌患者血清PSA水平对Gleason评分的预测价值

目的探讨前列腺腺癌患者血清前列腺特异性抗原(PSA)水平对Gleason评分的预测价值。方法研究血清PSA三种主要指标和Gleason分级主要指标均值;比较不同组别之间的差异,分析血清PSA与Gleason评分相关性,并观察血清总PSA(tPSA)与Gleason评分之间变化趋势。结果血清tPSA≤4.0、4.1~10.0、10.1~20.0、20.1~100.0、100.0ng/mL组Gleason评分均值分别为6.31±0.47、6.66±0.89、7.04±1.11、7.56±1.03以及7.91±1.01;血清游离PSA(fPSA)≤1.0、1.1~10.0、10.0组Gleason评分均值分别为6.45±0.69、6.98±0.98以及7.75±1.05;血清总PSA(tPSA)t/fPSA≤0.16、0.17~0.50以及0.50组Gleason评分均值分别为6.72±0.88、7.45±1.04以及8.36±1.12。血清tPSA、fPSA以及fPSA/tPSA比值分别与Gleason评分、主要分级以及次要分级显著正相关;Gleason评分、主要分级以及次要分级均随血清tPSA、fPSA以及fPSA/tPSA逐渐增加而增加。结论前列腺腺癌患者血清PSA对Gleason评分的具有预测价值;与fPSA和fPSA/tPSA比值相比,tPSA是最有预测价值的指标。     

结合前列腺特异性抗原在前列腺癌诊断中的临床价值

目的探讨结合前列腺特异性抗原(cPSA)在前列腺癌中的临床诊断意义。方法用化学发光免疫分析法检测前列腺癌(Pca)25例,前列腺增生(BPH)30例及正常对照组30例的血清总前列腺特异性抗原(tPSA)、cPSA和游离前列腺特异性抗原(fPSA)的浓度;计算f/tPSA比值并对tPSA、f/tPSA、cPSA进行统计学比较和ROC曲线分析。结果cPSA、tPSA在BPH组、Pca组分别与正常对照组比较均存在显著性差异(p<0.005),若以cPSA15.75ng/ml作为截断点诊断Pca,其敏感性、特异性、阳性预测值、实验有效率各参数均比较理想,分别为79.17%,92.86%,90.48%,88.46%。另tPSA,cPSA,fPSA三者在ROC曲线下的面积分别为tPSA>cPSA>f/tPSA。结论cPSA在鉴别前列腺增生和前列腺癌中具有较大的临床价值,建议临床以cPSA15.75ng/ml作为截断点,这能大幅度地提高cPSA对前列腺癌的检出率,减少或避免不必要的前列腺活检。     

f/tPSA比值对tPSA值为2.6～4.0ng/ml前列腺癌的诊断意义

目的探讨利用血清游离前列腺特异性抗原(fPSA)和总前列腺特异性抗原(tPSA)的比值(f/tPSA),提高tPSA2.6～4.0ng/ml前列腺癌的诊断率的价值。方法对117例tPSA在2.6～4ng/ml可疑前列腺癌患者行直肠B超引导下前列腺穿刺活检,对患者血清tPSA,fPSA及f/t PSA值及其他临床病理资料进行统计学分析。结果经病理诊断良性前列腺增生(BPH)82例和前列腺癌35例,35例癌中Gleason score≤4分共6例(17%),Gleason score5-7分和8-10分别为22例(63%)和7例(20%)。前列腺癌的f/tPSA明显高于BPH(P＜0.01),以f/tPSA0.22为界值,诊断癌的特异性为83%,敏感性为71%,阳性预测值为68%。结论f/t PSA作为一项辅助检查可提高tPSA 2.6～4.0ng/ml前列腺癌的诊断率。     

血浆纤维蛋白原水平与前列腺癌临床病理特征的关系研究

目的分析血浆纤维蛋白原(FIB)与前列腺癌临床病理特征的关系,探讨FIB在前列腺癌患者病情评估中的临床价值。方法回顾性分析从2006年1月至2017年12月间珠江医院456例前列腺癌(PCa)患者及322例前列腺增生(BPH)患者的临床病理资料。分析前列腺癌患者术前血浆纤维蛋白原水平与纤维蛋白原(FIB)、Gleason评分、总前列腺特异抗原(tPSA)值、游离前列腺特异抗原(fPSA)值、游离前列腺特异抗原百分比(f/tPSA)、年龄、体质量指数(BMI)、临床T分期(cT)、有无淋巴结转移、有无骨转移、危险度分级之间的相关性。结果两组患者的术前血浆FIB中位水平分别为3.52(2.97~4.35)g/L、3.12(2.61~3.45)g/L。前列腺癌组显著高于前列腺增生组,差异有统计学意义(P<0.05)。前列腺癌患者术前血浆FIB水平与年龄、tPSA、Gleason评分、c T分期改变呈正相关性(P<0.05)。结论前列腺癌患者术前血浆纤维蛋白原水平与肿瘤病理评分、临床T分期以及相关血清指标有密切关系,可以联合相关影像及实验室检查结果预测患者疾病进展情况及其转归。     

ROC曲线分析比较tPSA、fPSA／tPSA和PSAD在PSA灰区前列腺癌诊断中的价值

目的 ROC曲线分析探讨前列腺特异性抗原密度(PSAD)、总PSA(tPSA)和游离PSA/总PSA(fPSA/tPSA)3者在PSA灰区前列腺癌(PCa)中的临床诊断价值.方法 同顾性分析tPSA在4～10ng/ml之间的前列腺增生(BPH)患者75例和前列腺癌患者31例.化学发光法测定血清tPSA和fPSA,经直肠超声(TRUS)测定前列腺体积,计算fPSA/tPSA和PSAD.比较BPH组和PCa组间tPSA、PSAD和fPSA/tPSA各指标的差异,分析各指标在ROC曲线卜的面积、各指标的诊断特异性及敏感性.结果 PCa组与BPH组tPSA差异无统计学意义(P＞0.05),PCa组fPSA/tPSA比值较BPH组降低(P＜0.01),PSAD值较BPH组升高(P＜0.05).ROC曲线下的面积从大到小为fPSA/tPSA＞PSAD＞tPSA.在诊断敏感性相同的情况下,fPSA/tPSA比值诊断特异性高于PSAD的诊断特异性.当fPSA/tPSA临界值取0.16时,诊断前列腺癌的灵敏度和特异性为67.7%和79.7%,PSAD临界值取0.12时,其灵敏度和特异性为61.3%和62.7%.结论 当tPSA在诊断灰区时,PSAD和fPSA/tPSA可以提高前列腺癌的诊断特异性和敏感性,fPSA/tPSA较PSAD有更高的诊断价值.     

血清tPSA、PSAD及Gleason评分在前列腺癌分期中的应用价值

目的:探讨血清前列腺特异性抗原(PSA)系列及穿刺组织活检Gleason评分在前列腺癌病理分期的预测价值。方法:回顾性分析我院1999～2008年病理证实为前列腺腺癌的124例患者资料,将该124例患者根据术后病理、骨扫描和CT或MRI结果分为A、B两组。骨扫描、CT、MRI或术后证实为有周围浸润或远处转移者归为A组;无周围浸润且无远处转移者归为B组。比较两组之间以上各指标的差异。通过多因素回归分析筛选前列腺癌病理分期的影响因子。运用工作特征曲线(ROC曲线)比较各指标的预测价值。结果:tPSA、穿刺活检Gleason评分值A组明显高于B组(P<0.05);多元Logistic回归分析中,仅tPSA进入模型,被认为是最主要的预测因子。ROC曲线对前列腺病理分期预测效力比较:联合分析tPSA与穿刺活检Gleason评分预测效果明显高于其他指标,工作特征曲线下面积(AUC)从大到小依次为Gleason评分+tPSA>tPSA>PSAD+tPSA+Gleason评分。结论:tPSA依然是临床上对前列腺癌病理分期较好的预测因素;联合穿刺组织活检Gleason评分,可以提高预测准确度,对指导临床治疗和预后有重要意义。     

前列腺健康指数的发现与应用

前列腺特异抗原(PSA）是目前临床上用来诊断前列腺癌(PCa)的最常用指标，但是当PSA为4～10 ng/mL时，即临床上称为PSA灰区时， PSA对诊断PCa的特异性较低。前列腺健康指数(PHI）是总前列腺特异抗原(tPSA）、游离前列腺特异抗原(fPSA）和前列腺特异性抗原同源异构体(p2PSA)的多因素数学组合，其诊断效能显著高于PSA。PHI一经发现后就引起了国际学者的关注，并在过去的10年内发展迅速。本文对PHI发现和发展的历程进行简要梳理，以期为临床上PCa的早期诊断和筛查提供诊断思路。     

ELRP与开放术治疗前列腺癌的效果对比及血清PSMA、FPSAR的差异性表达

目的 探讨经腹膜外入路前列腺根治性切除术(ELRP)与开放术治疗前列腺癌的效果对比及血清前列腺特异性膜抗原（PSMA）、游离前列腺特异抗原百分率（FPSAR）的差异性表达。方法 回顾性分析2016年1月至2021年1月本院收治的62例前列腺癌患者的临床资料，按术式的不同分为研究组（36例，行ELRP术）和对照组（26例，行传统开放手术）。比较两组患者的围手术期情况，包括手术时间、术中出血量、住院时间、术后通气时间、尿管拔除时间。对比分析两组患者的术后并发症发生率。采用国际前列腺癌生活质量评分标准对两组患者的生活质量进行评估。记录两组患者术后１年的尿失禁发生率。采用酶联免疫吸附测定（ELISA）法检测患者PSMA水平，采用化学发光分析法测定总前列腺特异抗原（tPSA）、游离前列腺特异抗原（fPSA）水平，计算FPSAR（fPSA/tPSA）。结果 研究组的手术时间、术中出血量、住院时间、术后通气时间、尿管拔除时间均短于对照组（均P<0.001）；研究组的术后并发症发生率低于对照组[11.11%（4/36）vs.34.62%（9/26），P<0.05]；研究组术后1个月、术后6个月的生活质量评分高于对照组（P<0.05），且两组术后1个月、术后6个月的生活质量评分均高于术前（均P<0.05）；研究组的术后１年尿失禁发生率为2.78%（1/36），低于对照组的11.54%（3/26）（P<0.05）；两组术后1周的血清PSMA低于术前，血清FPSAR水平高于术前（均P<0.05），但两组术后1周的血清PSMA、FPSAR水平比较，差异均无统计学意义（均P>0.05）。结论 与开放术比较，ELRP术可改善围手术期情况，降低术后并发症发生率和尿失禁发生率，提高患者的生活质量，并且对术后患者的血清PSMA、FPSAR水平产生影响。     

Comparisons of the various combinations of free, complexed, and total prostate-specific antigen for the detection of prostate cancer

OBJECTIVES: We compared the ability of three prostate-specific antigen (PSA) ratios - free-to- total PSA ratio (fPSA/tPSA), free-to-complexed PSA ratio (fPSA/cPSA), and complexed-to-total PSA ratio (cPSA/tPSA) - to distinguish prostate cancer from benign prostatic hyperplasia (BPH). METHODS: We tested 258 consecutive patients who underwent transrectal ultrasound-guided prostate needle biopsy because of an abnormal digital rectal examination or a Tandem-R PSA of >4.1 ng/ml. Free PSA (fPSA) and total PSA (tPSA) were measured by Tandem-R assay. alpha(1)-Antichymotrypsin-complexed PSA (cPSA) was measured by Markit-M PSA-ACT assay. RESULTS: Of the 258 patients, 204 had BPH, and 54 had prostate cancer. The specificity at 96% sensitivity for fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA was 23, 25, and 33%, respectively. Of 162 patients with tPSA between 4.1 and 10.0 ng/ml, 132 had BPH and 30 had prostate cancer. The specificity at 96% sensitivity for f/tPSA, f/cPSA and c/tPSA was 32, 44, and 41%, respectively. There was no significant difference in the area under the receiver-operating characteristic curves among fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA in the overall PSA range or in tPSA between 4.1 and 10.0 ng/ml. CONCLUSION: fPSA/tPSA, fPSA/cPSA, and cPSA/tPSA did not differ in their ability to distinguish prostate cancer from BPH.     

Comparative evaluation of various prostate specific antigen ratios for the early detection of prostate cancer

OBJECTIVE: To compare the performance of various ratios using total prostate specific antigen (PSA), complexed PSA (cPSA) and free PSA (fPSA) in the early detection of prostate cancer. PATIENTS AND METHODS: The study included 535 consecutive patients evaluated at a prostate cancer detection clinic between January 1998 and October 1999. Patients had blood samples drawn before transrectal ultrasonography and prostate biopsy to measure PSA, cPSA and fPSA. Receiver operating characteristic (ROC) curves (sensitivity vs 1 - specificity) were used to evaluate the performance of PSA, cPSA, f/tPSA, cPSA/tPSA, fPSA/cPSA, tPSA/prostate volume (PV), fPSA/PV, and cPSA/PV. The areas under the curve (AUC) were calculated for each ratio. The performance of each ratio over all patients or in those with a tPSA of 4-6 or 4-10 ng/mL were evaluated. RESULTS: Of the 535 patients, 204 (38%) had biopsy-confirmed prostate cancer. The AUC obtained with tPSA alone was 0.64; when measured for all patients the cPSA/PV (0.78), PSA/PV (0.77), f/tPSA (0.76) and fPSA/cPSA (0.75) performed better than tPSA alone. Furthermore, in patients with a tPSA of 4-10 ng/mL, tPSA/PV (0.72), cPSA/PV (0.71), f/tPSA (0.69), fPSA/cPSA (0.69) and cPSA/tPSA (0.62) performed better than tPSA alone (0.52). Finally, in patients with a tPSA of 4-6 ng/mL, PSA/PV and cPSA/PV performed better than the other ratios. CONCLUSIONS: The use of PSA ratios gives a higher sensitivity and specificity for detecting prostate cancer than the use of tPSA alone.     

Comparison of two investigative assays for the complexed prostate-specific antigen in total prostate-specific antigen between 4.1 and 10.0 ng/mL

OBJECTIVES: To determine the ability of complexed prostate-specific antigen (cPSA) levels to diagnose prostate cancer. METHODS: Between September 1998 and March 1999, cPSA levels in 182 consecutive patients with an abnormal digital rectal examination (DRE) or a total PSA (tPSA; Tandem-R assay) level greater than 4.1 ng/mL were examined. Levels of cPSA were measured by the Markit-M PSA-ACT (alpha(1)-antichymotrypsin) assay (cPSA-MM) and Bayer Immuno 1 complexed PSA assay (cPSA-BI). Free PSA (fPSA) was measured by the Tandem-R free PSA assay. RESULTS: Of the 140 patients with tPSA between 4.1 and 10.0 ng/mL, 116 were histologically confirmed as having benign tissue; the remaining 24 were diagnosed with prostate cancer. To ensure a 92% sensitivity of cancer detection, a cutoff value for the tPSA, cPSA-MM, and cPSA-BI assays of 4.8 ng/mL, 2.7 ng/mL, and 4.6 ng/mL, respectively, was determined. The percentage of negative biopsies prevented at these cutoff (ie, specificity) values was 14%, 23%, and 24%. No significant differences among these three assays were found. At 92% sensitivity, the cutoff value for the fPSA/tPSA, fPSA/cPSA-MM, and fPSA/cPSA-BI ratios was 18%, 27%, and 18%, respectively. The specificity was 35%, 49%, and 51%. No significant differences were found among these three fPSA ratios. Significant differences were noted between tPSA and the fPSA/cPSA-MM ratio and between tPSA and the fPSA/cPSA-BI ratio. No differences were seen among the other PSA parameters. CONCLUSIONS: No difference in the ability of cPSA levels to distinguish prostate cancer and noncancer was observed between cPSA-MM and cPSA-BI or between their fPSA ratios. Only the fPSA/cPSA-MM and fPSA/cPSA-BI ratios provided significantly enhanced diagnostic performance compared with tPSA.     

Predictors of prostate cancer on repeat prostatic biopsy in men with serum total prostate-specific antigen between 4.1 and 10 ng/mL

OBJECTIVES: We determine whether the different molecular forms of prostate-specific antigen (PSA) and other PSA variables can predict prostate cancer in men undergoing repeat prostate needle biopsy. METHODS: Between 1997 and 2001, repeat biopsy was performed in 97 patients who had undergone prior negative prostate biopsy. The ability of total PSA (tPSA), complexed PSA (cPSA), free PSA (fPSA), free-to-total PSA (fPSA/tPSA), free-to-complexed PSA (fPSA/cPSA), complexed-to-total PSA (cPSA/tPSA), tPSA density (tPSAD), cPSA density (cPSAD), transition zone tPSA density (tPSATZ) and transition zone cPSA density (cPSATZ) was assessed by univariate and multivariate analyzes as well as receiver operating characteristics (ROC) curves. RESULTS: Prostate cancer on repeat biopsy was detected in 24% of subjects (23 of 97) who had a negative initial biopsy. The PSA parameters cut-off to ensure a 96% sensitivity of cancer detection, were 29% using fPSA/tPSA, 32% using fPSA/cPSA, 0.18 ng/mL/cc using tPSATZ and 0.16 ng/mL/cc using cPSATZ. The fPSA/tPSA would have prevented 32% of negative biopsies, the fPSA/cPSA 28%, the tPSATZ 23% and the cPSATZ 30%. ROC curve analysis fPSA/tPSA, fPSA/cPSA ratios, tPSATZ and cPSATZ were significantly better predictors of repeat biopsy results than tPSA or cPSA, but there was no significant difference in the ROC curves among these four PSA parameters. In the multivariate logistic regression analysis these four PSA parameters were significant predictors for cancer detection in the repeat biopsy group (P < 0.001). CONCLUSION: fPSA/tPSA ratio, fPSA/cPSA ratio, tPSATZ and cPSATZ enhance the specificity of PSA testing compared to tPSA or cPSA when determining which patients should undergo repeat biopsy.     

Mass screening of prostate cancer in a Chinese population：the relationship between pathological features of prostate cancer and serum prostate specific antigen

Aim: To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA). Methods: A total of 12027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen tPSA test (by Elisa assay). Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was > 4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subsequent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS. Inc., Chicago. USA). Results: Of the 12027 cases, 158 (including 137 patients whose serum tPSA values were 4.0 ng/mL and 21 patients [serum tPSA < 4.0 ng/mL] who had obstructive symptoms) undertook prostate biopsy. Of the 158 biopsies, 41 cases of prostatic carcinoma were found (25.9 %, 41/158). The moderately differentiated carcinoma and poorly differentiated carcinoma accounted for 61% and 34%, respectively. A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r = 0.312, P < 0.01) was established. A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r = 0.406, P < 0.01), indicating a significant linear relationship between serum tPSA and the size of tumor. Conclusion: This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men. Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer. This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.     

Diagnostic accuracy of percent free prostate-specific antigen in prostatic pathology and its usefulness in monitoring prostatic cancer patients.

INTRODUCTION: The aim of our study was to evaluate the clinical usefulness of percent free prostate-specific antigen (PSA) [ratio of free PSA (fPSA) to total PSA (tPSA); f/tPSA] in prostatic pathology and its usefulness in monitoring prostatic cancer patients. PATIENTS AND METHODS: Our prospective study was carried out on 470 consecutive male patients referred to our outpatient urological clinic for observation. We looked for relationships between tPSA, fPSA and percent free PSA and the patient's age, prostatic volume and histologic diagnosis as assessed by prostatic biopsies or surgical specimens (benign prostatic hypertrophy, carcinoma, hypertrophy with inflammation). In all cases, we calculated the specificity, sensitivity and diagnostic accuracy of percent free PSA in the diagnosis of prostatic diseases, using cutoff values ranging from 14 to 20%. In prostatic cancer patients, we considered the relationships between the various PSA molecular forms and staging, grading and follow-up values. We also evaluated the effects of hormonosuppressive therapy on the serum markers and noted for which tPSA value percent free PSA possessed the greatest diagnostic accuracy. RESULTS: While tPSA and fPSA values appeared to be correlated with patient age and prostatic volume, percent free PSA did not show a relationship with these parameters. The specificity, sensitivity and overall diagnostic accuracy were better assuming a 16% cutoff value for percent free PSA than with other cutoff values. Prostatic inflammation associated with benign hypertrophy can cause false positives in both tPSA and f/tPSA measurements, since 60% of these patients have an f/tPSA ratio below 16%. In diagnosing carcinoma, the diagnostic accuracy of percent free PSA is 100% when tPSA is between 2.5 and 4.0 ng/ml. Percent free PSA is not linked with staging in prostatic cancer, but it does appear to be related to the Gleason score. In patients receiving hormonosuppressive treatment, f/tPSA decreased significantly, and more so in patients with a higher Gleason score. In patients with disease in rapid progression, percent free PSA was lower than in patients in a stable condition. CONCLUSIONS: Based on our experience, 16% as the f/tPSA cutoff value for discriminating between benign and malignant pathologies is the best possible choice, as it provides the highest overall values of sensitivity, specificity and diagnostic accuracy (80, 61.5 and 84.5%, respectively) in the diagnosis of prostatic cancer. We believe that f/tPSA is not a definitive test for diagnosing prostatic cancer. Our observations on the behavior of percent free PSA in relation to prostatic carcinoma grading and staging and in the follow-up of carcinoma patients are interesting; however, further studies are needed to define the appropriate role of f/tPSA in patients with an established diagnosis of prostatic carcinoma and in the follow-up of patients with prostatic cancer.     

The percentage of free prostate-specific antigen does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy

OBJECTIVE: To determine whether the percentage of free/total prostate-specific antigen (f/tPSA) can predict the pathological features in patients with clinically localized prostate cancer before radical prostatectomy. PATIENTS AND METHODS: Univariate and multivariate logistic regression was used to analyse data from 171 untreated patients who underwent radical prostatectomy. Variables included the total PSA (tPSA), fPSA, f/tPSA, biopsy Gleason score, clinical stage and patient age. RESULTS: In 115 patients with pathologically organ-confined tumours ( pT2N0) the mean (SD) tPSA value was 6.9 (5.6) ng/mL; in 56 patients with extracapsular disease ( pT3pN0/N+) it was 10.2 (7.6) ng/mL; the respective f/tPSA values were 14.9 (8.1)% and 14.2 (12.9)%. In the univariate and multivariate analysis, tPSA and biopsy Gleason score were highly significant in predicting extracapsular disease (P < 0.001 and 0.002) but the f/tPSA was not (P = 0.18). There was no significant difference between the mean f/tPSA and final Gleason scores. CONCLUSION: The f/tPSA does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy. Knowing the f/tPSA provides no significant additional information in predicting extracapsular disease when the biopsy Gleason score and tPSA are known.     

Clinical utility of human glandular kallikrein 2 within a neural network for prostate cancer detection

OBJECTIVE

To assess, using artificial neural networks (ANNs), human glandular kallikrein 2 (hK2), prostate‐specific antigen (PSA), and percentage free/total PSA (f/tPSA), for discriminating between prostate cancer and benign prostatic hyperplasia (BPH).

MATERIAL AND METHODS

Serum samples from 475 patients with prostate cancer (n = 347) or BPH (n = 128) within the PSA range of 1–20 ng/mL were analysed for tPSA, fPSA and hK2 (research assay, Toronto, Canada). Data were analysed in the ranges of 1–4, 2–4, 4–10, and 2–20 ng/mL tPSA. Back‐propagation ANN models with the variables PSA, f/tPSA, and hK2, hK2/fPSA and hK2/(f/tPSA) were constructed. The diagnostic validity was evaluated by receiver‐operating characteristic (ROC) curve analysis.

RESULTS

Whereas the median concentration of hK2 was not significantly different between patients with BPH or prostate cancer in any of the tPSA ranges, the f/tPSA, hK2/fPSA and hK2/(f/tPSA), and the hK2‐based ANN outputs were always significantly different between patients with prostate cancer or BPH. Using ROC curve comparison, all variables were significantly better than hK2 in all ranges. The hK2‐based ANN performed better than f/tPSA except in the 4–10 ng/mL tPSA range. At 90% and 95% sensitivity, the hK2‐based ANN was also significantly better than f/tPSA in the 1–4 ng/mL tPSA range. hK2/(f/tPSA) achieved equal results to the hK2‐based ANN except in the range 2–20 ng/mL tPSA.

CONCLUSIONS

The hK2‐based ANN improves the outcome of f/tPSA but not hK2/(f/tPSA) in almost all analysed subgroups. When comparing the results at 90% and 95% sensitivity the hK2‐based ANN only performed significantly better than f/tPSA in the lowest tPSA range. Only in lower tPSA ranges do hK2‐based ANNs show an advantage for further improving prostate cancer detection.