Significance of prostate-specific antigen--alpha(1)-antichymotrypsin complex for diagnosis and staging of prostate cancer.

OBJECTIVE: To evaluate the clinical significance of measuring the prostate-specific antigen-alpha(1)-antichymotrypsin (PSA-ACT) for differentiating prostate cancer from benign prostate hypertrophy (BPH) and for the staging of prostate cancer. METHODS: Before treatment, total PSA (tPSA) and PSA-ACT were measured in 120 patients with prostate cancer and in 150 patients with BPH using immunofluorometric techniques with different monoclonal antibodies against PSA and ACT. Furthermore, the tPSA and PSA-ACT densities of the whole prostate (PSAD and ACTD, respectively) were calculated. RESULTS: tPSA, PSAD, PSA-ACT and ACTD levels in patients with prostate cancer paralleled the clinical stage and were significantly higher than those in patients with BPH. Furthermore, these four values were significantly higher in patients with pathologically extraprostatic disease than those with organ-confined disease. Receiver operating characteristics analysis among patients with PSA values of 4.1-10 ng/ml revealed that the areas under the curve for tPSA and ACTD were similar to those for PSA-ACT and ACTD, respectively and that no significant differences in the differentiation between prostate cancer and BPH were observed among these parameters. CONCLUSIONS: Measurement of PSA-ACT provides useful information for the clinical staging of prostate cancer and differential diagnosis between prostate cancer and BPH; however, compared with tPSA, PSA-ACT may not be significantly superior in the diagnosis and staging of prostate cancer.     

Value of free-to-total prostate-specific antigen ratio for detection and staging of prostate cancer

Background. We aimed to evaluate the clinical usefulness of measurement of the free-to-total (F/T) ratio of prostate-specific antigen (PSA) for the differentiation of prostate cancer from benign prostate hyperplasia (BPH) and for the staging of prostate cancer. Values for PSA density (PSAD) and PSAD adjusted to the transition zone volume (PSAD-T) were also evaluated in patients with mildly elevated PSA levels (4.1–10 ng/ml). Methods. Total and free PSA and the F/T ratio were determined in 80 men with prostate cancer and 48 men BPH before treatment. PSA levels were measured with a chemiluminescent enzyme immunoassay. Results. Patients with prostate cancer had a significantly lower F/T ratio than those with BPH. A cut-off value of 14% for the F/T ratio provided a positive predictive value of 81.6% and a negative predictive value of 65.4%. The F/T ratio did not differ between patients with clinically localized and metastatic prostate cancer. In patients with a PSA value of 4.1–10 ng/ml, a cut-off value of 14% for the F/T ratio provided a sensitivity of 66.7% and a specificity of 76.2%. Sixty percent of the missed cancer in patients with an F/T value of 14% or more could be rescued using the PSAD value. Conclusion. Measurement of the F/T PSA ratio has good sensitivity and specificity in distinguishing prostate cancer from BPH, especially in patients with a PSA level of 4.1–10 ng/ml. However, compared with serum PSA level, the F/T PSA ratio is not valuable for the clinical staging of prostate cancer. Received: June 23, 1999 / Accepted: September 22, 1999     

The ratio of prostate-specific antigen (PSA) to prostate volume (PSA density) as a parameter to improve the detection of prostate carcinoma in PSA values in the range of < 4 ng/mL

BACKGROUND: The objective of this study was to evaluate the prostate specific antigen (PSA) density (PSAD) (the quotient of PSA and prostate volume) compared with the percent free PSA (%fPSA) in different total PSA (tPSA) ranges from 2 ng/mL to 20 ng/mL. Possible cut-off levels depending on the tPSA should be established. METHODS: In total, 1809 men with no pretreatment of the prostate were enrolled between 1996 and 2004. Total and free PSA were measured with the IMMULITE PSA and Free PSA kits (Diagnostic Products, Los Angeles, CA). Prostate volume was determined by transrectal ultrasound. The diagnostic validity of tPSA, %fPSA, and PSAD was evaluated by receiver operation characteristic (ROC) curve analysis. RESULTS: The PSAD differed significantly (P < 0.0001) between patients with prostate carcinoma and patients with benign prostatic hyperplasia in all analyzed ranges of tPSA and prostate volume. At the 90% and 95% sensitivity levels and regarding the area under the ROC curve (AUC) within the tPSA range of 2-4 ng/mL, The PSAD was significantly better than tPSA and %fPSA. Within the tPSA range of 4-10 ng/mL, the PSAD did not perform better than %fPSA. CONCLUSIONS: PSAD showed a better performance than %fPSA at tPSA concentrations < 4 ng/mL for detecting prostate carcinoma, with a significantly larger AUC for PSAD (0.739) compared with %fPSA (0.667). PSAD did not perform better than %fPSA when the tPSA range of 4-10 ng/mL was analyzed. Different PSAD cut-off values of 0.05 at tPSA 2-4 ng/mL, 0.1 at tPSA 4-10 ng/mL, and 0.19 at 10-20 ng/mL were necessary to reach 95% sensitivity.     

Free-to-total prostate-specific antigen (PSA) ratio contributes to an increased rate of prostate cancer detection in a Japanese population screened using a PSA level of 2.1–10.0 ng/ml as a criterion

BACKGROUND: Although the free-to-total prostate-specific antigen (PSA) ratio (f/t ratio) is low in prostate cancer, its usefulness in mass screening remains unclear. We examined the clinical usefulness of the f/t ratio for screening in a Japanese population. METHODS: Since 2000, we have performed PSA screening in Japanese men aged 55-69 years. From 2000 to 2002, patients with total PSA (tPSA) levels over 2.1 ng/ml were referred to the urological clinic for secondary screening, regardless of the f/t ratio. We analyzed both the tPSA level and the f/t ratio in prostate cancer patients, and since 2003, subjects with tPSA levels ranging from 2.1-10.0 ng/ml and f/t ratios higher than 0.22 have not been referred for secondary screening. Here, we report the results of tPSA screening, comparing findings in the two periods (2000-2002 and 2003-2005). RESULTS: Between 2000 and 2005, we performed the tPSA screening test in 27 730 men, and detected 214 cases of prostate cancer. Sixty patients (28.0%) showed tPSA levels between 2.1 and 4.0 g/ml. There were no differences in cancer detection rates between the two periods in the populations referred for an initial screening. However, the percentage of individuals referred for secondary screening decreased from 17.0% to 13.0% during the later period (P < 0.001). The cancer detection rate in all patients with biopsies rose from 13.5% in the earlier period to 22.7% in the later period for the group with tPSA between 2.1 and 10.0 ng/ml (P < 0.001). CONCLUSION: The f/t ratio may be a useful additional screening parameter for patients showing tPSA levels between 2.1 and 10.0 ng/ml on their initial screening examination.     

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。     

复合PSA及相关指标在前列腺癌诊断中的应用

Objective:To study the diagnostic value of complex PSA(cPSA),the calculated free/total PSA(f/t PSA) raio and total PSA(tPSA)in the differentiation of prostate cancer from benign prostate hyperplasia.Methods:The tPSA,cPSA and fPSA were measured using the Bayer ACS-180 chemiluminescence immuno-assay.152 patients(21 with prostate cancer and 131 with benign prostate hyperplasia proven by tissue pathology)whose serum total PSA ranged from 0.2-20.0ng/ml were accessed from July 2001 to May 2002 consecutively.The correlation between tPSA and cPSA was analyzed.The re-ceiver operator characteristic curves(ROC curve)were generated by plotting the sensitivity versus specificity.Areas under the curve were calculated for each assay.Logistic regression analysis was used to evaluate the ability of the indices as independent varia-bles to predict prostate cancer.Results:In the experimental group,the areas under the ROC curve of cPSA ,tPSA and fPSA/tPSA ratio were 0.811,0.799 and 0.376 respectively.The specificity for tPSA,fPSA/tPSA ratio and cPSA were 62%,57% and 4.7%,respectively,at cotoff yield-ing 95% sensitivity.Serum cPSA concentration was determined to be the best index among the three through logistic regression analy-sis.Conclusion:The serum levels of cPSA and tPSA are better indices than f/tPSA in the differentiation of prostate cancer from benign prostate hyperplasia.At the same level of sensitivity,cPSA has a higher specificity than tPSA.Serum cPSA may be a better indicator in the prediction of prostate cancer of early stage.     

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。     

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).     

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。     

Transperineal ultrasound-guided 12-core systematic biopsy of the prostate for patients with a prostate-specific antigen level of 2.5–20 ng/ml in Japan

Background The aim of this study was to investigate the cancer detection rate in patients with a prostate-specific antigen (PSA) level of 2.5 to 20ng/ml, using transperineal ultrasound-guided systematic biopsy of the prostate.Methods Three hundred consecutive patients with PSA levels of 2.5 to 20ng/ml underwent transperineal ultrasound-guided 12-core systematic biopsy of the prostate.Results Prostate cancer was detected in 108 of the 300 patients (36.0%). The cancer detection rates in patients with total PSA levels of 2.5–4.0, 4.01–10.0 and 10.01–20.0ng/ml were 18.2%, 31.0%, and 50.0%, respectively. The cancer detection rates in patients with prostate volumes of less than 30cc and over 50cc were almost 50%, and 13.3%, respectively. The cancer detection rate in patients with a PSA density (PSAD) of less than 0.10ng/ml per cc was only 5.6%, and no prostate cancer was detected in patients with a free-to-total PSA ratio (% f PSA) over 40%.Conclusion We demonstrated a high prostate cancer detection rate by the transperineal ultrasound-guided 12-core systematic biopsy method in patients with PSA levels of 2.5 to 20ng/ml. Accordingly, if the number of core biopsies is further increased overall, except in patients with a large prostate volume, and if the indication for biopsy is decided based on the PSAD and %f PSA, then the cancer detection rate by the present method may be further improved, with fewer unnecessary biopsies.     

前列腺癌实验室诊断指标的ROC曲线分析

目的应用ROC曲线分析血清游离前列腺特异性抗原（fPSA）,总前列腺特异性抗原（tPSA）及其比值（fP-SA/tPSA）在前列腺癌中的诊断价值。方法应用受试者工作特征曲线（ROC）对健康男性组,前列腺增生组及前列腺癌组血清tPSA,fPSA及fPSA/tPSA结果进行分析。结果前列腺癌组血清的tPSA、fPSA及f/t与其余两组比较均有差异。经ROC曲线分析,tPSA、fPSA及f/t的阈值分别为7.14μg/L、1.31μg/L及0.235。三者分别及联合检测的ROC曲线下面积分别为0.905、0.770、0.352与0.968。结论 tPSA、fPSA及f/t三者联合检测可以提高对前列腺癌的诊断。     

Clinical significance of the LacdiNAc‐glycosylated prostate‐specific antigen assay for prostate cancer detection

To reduce unnecessary prostate biopsies (Pbx), better discrimination is needed. To identify clinically significant prostate cancer (CSPC) we determined the performance of LacdiNAc‐glycosylated prostate‐specific antigen (LDN‐PSA) and LDN‐PSA normalized by prostate volume (LDN‐PSAD). We retrospectively measured LDN‐PSA, total PSA (tPSA), and free PSA/tPSA (F/T PSA) values in 718 men who underwent a Pbx in 3 academic urology clinics in Japan and Canada (Pbx cohort) and in 174 PC patients who subsequently underwent radical prostatectomy in Australia (preop‐PSA cohort). The assays were evaluated using the area under the receiver operating characteristics curve (AUC) and decision curve analyses to discriminate CSPC. In the Pbx cohort, LDN‐PSAD (AUC 0.860) provided significantly better clinical performance for discriminating CSPC compared with LDN‐PSA (AUC 0.827, P = 0.0024), PSAD (AUC 0.809, P < 0.0001), tPSA (AUC 0.712, P < 0.0001), and F/T PSA (AUC 0.661, P < 0.0001). The decision curve analysis showed that using a risk threshold of 20% and adding LDN‐PSA and LDN‐PSAD to the base model (age, digital rectal examination status, tPSA, and F/T PSA) permitted avoidance of even more biopsies without missing CSPC (9.89% and 18.11%, respectively vs 2.23% [base model]). In the preop‐PSA cohort, LDN‐PSA values positively correlated with tumor volume and tPSA and were significantly higher in pT3, pathological Gleason score ≥ 7. Limitations include limited sample size, retrospective nature, and no family history information prior to biopsy. LacdiNAc‐glycosylated PSA is significantly better than the conventional PSA test in identifying patients with CSPC. This study was approved by the ethics committee of each institution (“The Study about Carbohydrate Structure Change in Urological Disease”; approval no. 2014‐195).     

A new Model Consists of Intravesical Prostatic Protrusion,Prostate Volume and Serum Prostatic-Specific Antigen in the Evaluation of Prostate Cancer

The Prostate-specific antigen (PSA) level is largely used to diagnose prostate cancer (PCa) in last decades. However, its specificity is low in patients with a PSA level ranging from 4.0 to 10.0 ng/ml. This study aims to define the correlation between intravesical prostatic protrusion (IPP) and PSA and to establish a new model to predict PCa. A total of 339 patients order than 45 years examined between October 2010 and June 2012 were enrolled. Eligible patients were recommended for transrectal ultrasonography (TRUS)-guided prostate biopsies after measuring total prostate volume (TPV), tranzisional zone volume (TZV) and IPP. The levels of total PSA (tPSA), free PSA (fPSA) were analyzed by using Hybritech calibrated Access tPSA and fPSA assays. A new mathematical model, named IPP removed PCa predicting score (IRPPS), consists of tPSA, TZV and IPP was established. The predictive accuracy of IRPPS, PSA density (PSAD), %PSA and tPSA were compared using receiver-operator characteristic (ROC) analysis. Eighty-six patients had PSA levels of 4.0–10.0 ng/ml. Twenty of them were diagnosed as PCa. Using ROC curves, the areas under the curve for IRPPS, PSAD and %PSA and tPSA were 0.786, 0.768 and 0.664 and 0.585, respectively. We suggested IPP grade had a significant relationship with serum tPSA levels. The predictive accuracy of IRPPS was higher than the other 3 indictors.     

Evaluation of free-to-total prostate specific antigen ratio in the diagnosis of prostate cancer

It'sreportedthatfreetototalprostatespecificantigenration(f/tPSA)canprovidemorebenefitthanthesingleuseofprostatespecificantigen(PSA)inthediagnosisofprostatecancer(PCa).WemeasuredserumPSAandfPSAlevelsin62casesofbenignprostatichyperplasia(BPH)and40casesofPCausingradioimmunoassay,withpatients'agerange59y-89y.RESULTSPSA,fPSAandf/tPSAareshowninTable1.BoththesetwogroupsshowslinearcorrelationbetweenPSAandfPSA,correlationcoefficientofBPHis0.55(P<0.01),ofPCais0.44(P<0.01).Twoslopesha…     

Molecular forms of prostate‐specific antigen in serum with concentrations of total prostate‐specific antigen <4 μg/L: Are they useful tools for early detection and screening of prostate cancer?

Molecular forms of prostate-specific antigen (PSA) improve the differentiation between benign prostatic hyperplasia (BPH) and prostate cancer (PCa) in men with total PSA concentrations between 4 and 10 microg/l. To evaluate the diagnostic utility of free PSA (fPSA) and complexed PSA forms for identification of men with PCa in the low PSA range of <4 microg/l, total PSA (tPSA), alpha(1)-antichymotrypsin complexed PSA (PSA-ACT) and fPSA (Roche Elecsys [ES] system) as well as tPSA and complexed PSA (cPSA) (Bayer Immuno 1 system) were measured in archival serum samples from 31 untreated patients with PCa, 66 patients with BPH, and 90 men without prostatic disease. The median ratios of fPSA/tPSA, PSA-ACT/tPSA and cPSA/tPSA were significantly different between patients with BPH and PCa (27.2 vs. 19.4%, 64 vs. 88%, 77.2 vs. 88.2%, p < 0.05). No associations between PSA forms and tumor stage and grade were found. Analysis of the receiver operating characteristic curves showed that these ratios could discriminate better between BPH and PCa patients than determination of the analytes tPSA, fPSA, cPSA and PSA-ACT alone. The use of one of the ratios would have eliminated roughly half of the unnecessary biopsies in this study. The ratios should be considered as potential tools to increase the selectivity of PCa detection at low PSA concentration. The ratios fPSA/tPSA and cPSA/tPSA can be determined using commercially available assays so that one of these ratios could be preferred instead of PSA-ACT determination. The ratios could be useful in assessing the risk of PCa in the individual and therefore in deciding on prostate biopsy for final diagnosis.     

Prostate specific antigen complexed to alpha-1-antichymotrypsin in patients with intermediate prostate specific antigen levels

BACKGROUND: The authors attempted to evaluate prospectively the usefulness of serum prostate specific antigen (PSA) complexed to alpha-1-antichymotrypsin (PSA-ACT) in the early detection of prostate carcinoma and its ability to discriminate between prostate carcinoma and benign prostatic hyperplasia (BPH), especially among patients with intermediate PSA levels. METHODS: Between December 1999 and August 2000, systematic sextant biopsies were performed on 281 prospective patients with prostate carcinoma who had serum PSA levels between 4.1 ng/mL and 20.0 ng/mL. The serum samples were assayed by using kits that were designed specifically for measuring serum PSA, PSA-ACT, and free PSA levels. The clinical values of PSA, PSA-ACT, the free PSA to total PSA ratio (F/T ratio), the free PSA to PSA-ACT ratio, PSA density (PSAD), and PSA-ACT density (ACTD) were compared by using receiver operating characteristic (ROC) curve analysis. RESULTS: Biopsy yielded no evidence of malignancy in 198 patients, and prostate carcinoma was confirmed in 83 patients. ROC analysis demonstrated that the area under the curve (AUC) for PSA-ACT was greater than that for total PSA and was equivalent to that for the F/T ratio in both groups of patients (PSA ranges of 4.1-20.0 ng/mL and 4.1-10.0 ng/mL, respectively). The AUC for the ACTD was greater than the AUC for the PSAD and had the highest value of all parameters. CONCLUSIONS: The measurement of PSA-ACT represents an alternative to the use of total and free PSA. The ACTD value is the most useful for discriminating between BPH and prostate carcinoma.     

Rationale for using serum prostate-specific antigen (PSA) level and PSA density (PSAD) to detect prostatic malignancy in a country with low prostate cancer incidence

Prostate-specific antigen (PSA) and PSA density (PSAD) values in Indonesia had been found uniquely much higher than the normal accepted values in western countries. However, PSA more than 10 ng/ml and PSAD above 0.15 in intermediate PSA of 4-10 ng/ml are still indicative of a prostate biopsy. This condition had led to unnecessary biopsies in view of the low incidence of prostatic carcinoma in our country. Our objective is to find alternative serum PSA levels and PSAD cutoff points that enhance the specificity and sensitivity of prostate cancer detection. This retrospective cross-sectional study included 805 consecutive patients from 40 to 95 years old in Sumber Waras Hospital (SWH) and Cipto Mangunkusumo Hospital (CMH) from 1994 to 1997. All patients underwent digital rectal examination (DRE) and transrectal ultrasonography (TRUS) to measure prostate volume. After the serum PSA level was determined and PSAD was calculated, prostate biopsies were performed if the PSA level was greater than 10 ng/ml or PSAD more than 0.15 at intermediate PSA levels of 4-10 ng/ml. The ability of PSA, intermediate PSA level, and PSAD to improve the accuracy of prostate cancer detection was evaluated using univariate analysis. Among 805 patients, 240 patients had PSA level < 4 ng/ml, 230 patients had PSA level 4-10 ng/ml, and 335 had PSA level > 10 ng/ml. Of the 230 patients with intermediate PSA level, 108 had PSAD > 0.15. Thirty-five patients had histologically confirmed prostatic carcinoma, i.e., 3 of 108 patients with PSA 4-10 ng/ml and PSAD > 0.15, and 32 of 335 patients with PSA > 10 ng/ml. There were 105 and 303 unnecessary biopsies in those groups. With a PSA cutoff level of > or = 8 ng/ml, we found 100% sensitivity to prostate cancer. PSAD > or = 0.20 within a PSA level of 8-30 ng/ml gave 100% sensitivity to prostate cancer. Using these new cutoffs there would be 148 biopsies (33.4%) saved. We concluded from this study that the commonly accepted values of serum PSA level and PSAD resulted in many unnecessary biopsies in our patients. Instead, the most sensitive cutoff points to perform prostate biopsy are serum PSA level greater than 8.0 ng/ml, and PSAD of more than 0.20 at an intermediate serum PSA level of 8-30 ng/ml.     

前列腺特异性抗原的检测对前列腺癌及前列腺增生的诊断意义

目的　探讨血清总前列腺特异性抗原 (t PSA)、游离PSA (f PSA)、PSA密度 (PSAD )及其f PSA/t PSA比值对前列腺癌 (PCa)及前列腺增生 (BPH )的诊断价值。方法　采用酶联免疫分析方法 (ELISA )检测未经治疗的 62例BPH患者和 2 4例PCa患者血清f PSA、t PSA水平 ,并计算f PSA/t PSA值和PSAD ,对检测结果进行统计学处理。结果　BPH组与PCa组的f PSA、t PSA水平均明显高于对照组 (P <0 .0 1) ;前列腺癌组的f PSA /t PSA值明显小于对照组及前列腺癌增生组 (P <0 .0 1) ;PCa组PSAD明显大于对照组和BPH组 (P <0 .0 1)。结论　检测f PSA/t PSA和PSAD比单一检测f PSA、t PSA可显著提高对PCa诊断的特异性及符合率 ,对前列腺体积较大的BPH和PCa患者 ,检测PSAD更有意义     

The Significance of PSA Modified Parameters （F/T）/ PSAD for Diagnosing Prostatic Cancer in the Grey Zone of 4-10 ng/ml

OBJECTIVE To investigate the diagnostic value of modified prostate specific antigen(PSA)parameters in the diagnosis of prostate cancer(PCA) when the serum PSAis in a grey zone of 4~10 ng/ml. METHODS The results of serum PSA determinations of the patients receiving a transrectal ultrasound-guided multiphase prostatic biopsy,were retrospectively analyzed.In the 88 patients with a serum PSA value of 4-10 ng/ml,the final diagnosis of PCA was made in 21,and that of benign prostate hyperplasia(BPH)in 67 patients.The percentage of the free-serum PSA([FPSA]/total-serum PSA[TPSA],F/T),PSA density(PSAD)and the sensitivity and specificity of the new PSA modified parameter(F/T)/PSAD in diagnosing PCA,within a set threshold value,was compared. RESULTS In the 88 patients with serum PSA in the grey zone of 4.0-10.0 ng/ml,there was no significant difference in comparing the TPSA between the 21 PCA patients and 67 BPH patients(P>0.05).However, there was a significant difference in the value of modified PSA parameters, such as F/T,PSAD and(F/T)/PSAD,between the PCA and the BPH groups (P<0.001).As the cut off point-value of the F/T,PSAD and(F/T)/PSAD was set at 0.16,0.15 and 0.8,the diagnostic sensitivity for PCA was 66.7%, 76.2%and 85.7%,and the specificity was 41.8%,43.3%and 68.7%,respectively.There was no significant difference in the sensitivity comparing the modified parameters for diagnosing PCA(P>0.05),whereas an overt predominance was present in the specificity of(F/T)/PSAD for PCAdiagnosis (P<0.05). CONCLUSION In the serum PSA grey zone of 4-10 ng/ml,a modified PSA parameter can improve the PCA diagnostic accuracy rate.With a considerably high sensitivity,application of the(F/T)/PSAD may effectively enhance the diagnostic specificity,which is superior to the F/T and PSAD, and can be expected to be one of the new indices derived from the PSA.