血清PSA、PSAD和PSAT在前列腺穿刺活检中的意义

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)和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192例患者行前列腺穿刺活检,其中PSA≥4ng/ml者184例,PSA<4ng/ml且直肠指诊及经直肠B超有阳性发现者8例。对PSA、PSAD和PSAT与前列腺穿刺活检的关系进行分析。结果192例患者中经前列腺穿刺诊断为前列腺癌(PCa)100例,活检阳性率52.1%,其中8例PSA<4ng/ml者中,活检结果为前列腺横纹肌肉瘤1例,良性前列腺增生7例;93例PSA>20ng/ml者中80例为PCa,活检阳性率86.0%;91例PSA4~20ng/ml者中19例为PCa,活检阳性率20.9%。血清PSA4~20ng/ml患者,PSAD>0.10或PSAT>0.10时,敏感性均为100%,特异性为11.1%或4.2%,阳性预测值为22.9%或21.6%,可避免8.8%(8/91)或3.3%(3/91)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(13.2±4.7)和(11.4±4.6)ng/ml(P>0.05);PSAD分别为0.36±0.18和0.19±0.09(P=0.001);PSAT分别为0.67±0.36和0.32±0.18(P=0.000)。血清PSA、PSAD和PSAT的ROC曲线下面积分别为0.613、0.810和0.833,PSAD和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PSA>20ng/ml时应做前列腺穿刺活检;PSA4~20ng/ml时,PSAD和PSAT对预测患者是否行前列腺穿刺活检有较大帮助。     

Clinical value of prostate specific antigen based parameters for the detection of prostate cancer on repeat biopsy: the usefulness of complexed prostate specific antigen adjusted for transition zone volume

PURPOSE: To our knowledge the indications for repeat prostate needle biopsy in men whose previous transrectal ultrasound guided biopsy results revealed no evidence of cancer have not yet been defined. We identified the most effective method for detecting prostate cancer on repeat biopsy. MATERIALS AND METHODS: One or more systematic repeat prostate biopsies were performed in 144 consecutive patients, including 86 with prostate specific antigen (PSA) levels between 4 and 10 ng./ml. at repeat biopsy. Men in whom cancer was detected on repeat biopsies were compared with their counterparts in terms of digital rectal examination findings, PSA based parameters and an atypical prostate on initial prostate biopsy. RESULTS: Prostate cancer was detected on repeat biopsy in 39 of the 144 patients and in 19 on subset analysis of 86. Serum PSA levels at repeat biopsy did not differ significantly in patients with and without prostate cancer. According to receiver operating characteristics analysis the alpha1-antichymotrypsin-PSA complex adjusted for transition zone volume had the greatest area under the curve values, that is 0.756 for all 144 patients and 0.768 for the subset analysis of 86. Multiple logistic regression analysis of the subset of 86 patients showed that alpha1-antichymotrypsin-PSA complex adjusted for transition zone volume was the only significant independent predictor of cancer. CONCLUSIONS: alpha1-Antichymotrypsin-PSA complex adjusted for transition zone volume was the most powerful predictor of cancer in men who had undergone previous negative prostate biopsies. This parameter may be used to avoid more unnecessary repeat biopsies with an acceptable decrease in sensitivity.     

Effectiveness of percent free prostate specific antigen as a predictor of prostate cancer detection on repeat biopsy

BACKGROUND: The aim of this study was to identify predictors that can increase the accuracy of detecting prostate cancer on subsequent biopsies. METHODS: Between 1998 and 2003, a total of 235 men with prostate specific antigen (PSA) levels between 4.0 and 20 ng/mL underwent one or more systematic needle biopsies of the prostate. Of these men, 73 (31.1%) underwent one repeat biopsy and 26 (11.1%) underwent two or more repeat biopsies. We evaluated the results of prostate biopsies in relation to the morbidity of prostate cancer detected on repeat biopsies. RESULTS: Of the 73 men who underwent repeat biopsy, 16 (21.9%) had prostate cancer. Twenty-six men with one negative re-biopsy underwent two or more repeat biopsies, and five of these patients were found to have early stage prostate cancer. On repeat biopsy, there was a significant difference in percent free PSA between the cancer-detected group and the no-cancer-detected group (P < 0.01). A receiver operating characteristics (ROC) curve gave an optimal cut-off value for percent free PSA of 11%, demonstrating a significant difference in the cancer detection rate on repeat biopsy (P = 0.0009). Analysis of the data for re-biopsies showed that cancer-detected cases showed a raised PSA value and a simultaneously reduced percent free PSA (these differences were statistically significant). CONCLUSIONS: A low percent free PSA level increased the probability of a positive result in repeat biopsy. An increase in the accuracy of detecting cancer, especially on repeat biopsy, will promote the detection of more early stage prostate cancer.     

Implication of two additional lateral peripheral zone biopsy in the detection of prostate cancer

BACKGROUND: Despite the strenuous efforts in improving detection of prostate cancer, no standard technique for prostatic biopsy has been established to date. Extended tissue sampling in peripheral zone may possibly lead to enhanced prostate cancer detection. METHODS: Four hundred thirty-three candidates for ultrasound-guided prostatic biopsy were alternately assigned to two groups regarding biopsy techniques between January 1997 and June 1998, Group A, sextant biopsy group and Group B, two additional lateral peripheral zone sampling after standard sextant biopsy. The outcomes of prostatic biopsy were compared. RESULTS: Cancer detection rates were 19.2% (43/217) in Group A and 18.5% (40/216) in Group B. No statistically significant difference was noted (p > 0.05). Clinical stage, Gleason score and the presence of metastasis did not differ significantly between groups (p > 0.05). The incidence and duration of hematuria, hematospermia were essentially the same between groups (p > 0.05). High fever due to possible bacteremia developed only in Group B patients (p = 0.04). CONCLUSIONS: Routine use of additional peripheral zone biopsy is not recommended owing to the equivalent cancer detection rates between groups. The application of additional biopsy should be determined carefully since this may lead to increased incidence of serious complications.     

Complexed prostate specific antigen improves specificity for prostate cancer detection: results of a prospective multicenter clinical trial

PURPOSE: Complexed (c) prostate specific antigen (PSA) has been shown to enhance specificity for prostate cancer (CaP) detection over total PSA (tPSA), although a large multi-institutional prospective evaluation was required to confirm these findings. We compared the clinical performance of cPSA with tPSA as a first line test for CaP detection and secondarily to determine if PSA ratios, namely percent free PSA (fPSA) and percent cPSA, can provide further enhancement in diagnostic performance over cPSA or tPSA. MATERIALS AND METHODS: Consecutive men scheduled for initial biopsy of the prostate were enrolled prospectively at each of 7 university centers and community based urology practices. Serum was collected and tested with the Immuno 1 (Bayer Diagnostics, Tarrytown, New York), tPSA and cPSA, and Access (Beckman, Inc., San Diego, California) fPSA and tPSA methods. RESULTS: A total of 831 patients were evaluated, of whom 313 (37.5%) were diagnosed with CaP. ROC curve analysis performed from the results of all samples and those within the clinically relevant cPSA ranges of 1.5 to 3.2, 1.5 to 5.1, 1.5 to 8.3 and 3.2 to 8.3 ng/ml (tPSA 2 to 4, 2 to 6, 2 to 10 and 4 to 10 ng/ml, respectively) indicated a significant improvement in the AUC ROC curve for cPSA compared with tPSA (p < or =0.001). Using cutoff points that provide a sensitivity of 80% to 95% for CaP detection within the 1.5 to 8.3 ng/ml cPSA range cPSA provided a statistically significant enhancement in specificity over tPSA of 6.2% to 7.9%. Within the cPSA range of 1.5 to 3.2 ng/ml using a cutoff point of 2.5 ng/ml for tPSA and 2.2 ng/ml for cPSA provided a specificity of 21.2% and 35%, respectively, and 85% sensitivity for CaP detection. PSA ratios provided no further enhancement in specificity over cPSA within these ranges. CONCLUSIONS: The use of cPSA as a single test provided improved specificity over tPSA. Percent fPSA and percent cPSA offered little to no additional benefit in the differentiation of benign and malignant disease at clinically relevant cPSA concentrations.     

Transition zone biopsy in the detection of prostate cancer

OBJECTIVE: About 25% of all prostate cancers occur in the transition zone (TZ). We analyzed the impact of 4 systematic TZ and 2 systematic apex (AP) biopsies in addition to systematic sextant biopsies in an effort to establish the diagnostic importance of early prostate cancer. METHODS: One hundred and thirty patients underwent systematic transperineal multipoint prostate biopsy (biopsy of 12 sites, including 4 TZ and 2 AP biopsies). RESULTS: Forty-one of 130 men (31.5%) had biopsy specimens positive for cancer, and cancer originated in the TZ alone in 4 of these 41 patients (9.8%). Fourteen patients underwent radical retropubic prostatectomy. We compare the pathological findings of radical prostatectomy specimens and biopsy results. Prostate cancers predicted to be stage T(2c) by TZ biopsy were all classified as pT(2c) or greater. CONCLUSIONS: Routine TZ biopsy does not substantially increase the prostate cancer detection rate; however, it can be useful in patients who require repeat biopsy.     

Prostate specific antigen adjusted for transition zone epithelial volume: the powerful predictor for the detection of prostate cancer on repeat biopsy

PURPOSE: The indications for repeat prostate biopsy for persistently increased prostate specific antigen (PSA) in men with prostate cancer never detected on previous biopsy are not clear. In this study we determined that PSA adjusted for transition zone (TZ) epithelial volume is the most powerful predictor for detecting prostate cancer on repeat biopsy. MATERIALS AND METHODS: Repeat prostate biopsies including additional TZ cores were performed in 75 men with PSA between 4.0 and 10.0 ng/ml. TZ epithelial volume was calculated by multiplying TZ volume by the percent of epithelium, which was measured by morphometric analysis using image analysis computer software. RESULTS: Prostate cancer was detected on repeat biopsy in 19 of the 75 patients. Patients with prostate cancer had a significant smaller percent area of epithelium or glandular lumen than those without cancer. In patients without prostate cancer TZ epithelial volume significantly correlated with total PSA. According to ROC analysis PSA adjusted for TZ epithelial volume had the greatest AUC for cancer detection (0.879). This parameter was able to avoid more than 90% of unnecessary repeat biopsies with 90% sensitivity. Multiple logistic regression analysis showed that PSA complex adjusted for TZ epithelial volume was the significant independent predictor of cancer. CONCLUSIONS: PSA adjusted for TZ epithelial volume is the most powerful predictor of cancer in men who have undergone previous negative prostate biopsies and in whom PSA remains between 4.0 and 10.0 ng/ml.     

Relationship between initial prostate specific antigen level and subsequent prostate cancer detection in a longitudinal screening study

PURPOSE: Previous studies of archived blood samples from nonscreened populations have shown an association between the prostate specific antigen (PSA) and the subsequent detection of prostate cancer. In the current study we evaluated the relationship between the initial screening PSA and the subsequent risk of prostate cancer detected in a prospective, longitudinal screening study. We also examined the relationship between initial PSA and the clinicopathological features of the cancers detected. MATERIALS AND METHODS: Between May 1991 and November 2001 we enrolled 26,111 volunteers in our PSA and digital rectal examination based prostate cancer screening study. The men were followed biannually or annually depending on the results of previous screening tests. The chi-square and Kruskal-Wallis tests were used to compare the clinical stage, pathological stage and Gleason score of subsequently detected prostate cancers as well as the time to cancer detection in different initial screening PSA strata. RESULTS: The initial screening PSA stratum was strongly associated with the subsequent detection of prostate cancer as well as the clinicopathological stage and grade of the cancers detected. CONCLUSIONS: Even in the lower PSA ranges initial screening serum PSA can help identify men at increased risk for subsequent prostate cancer detected in a longitudinal screening study.     

Utility of prostate specific antigen doubling time in repeat biopsy for prostate cancer

PURPOSE: It is not rare that the repeat biopsy is performed when the initial biopsy was negative. However, there is not a clear indication for the repeat biopsy. We evaluated the utility of prostate specific antigen doubling time (PSA-DT) as indication for the repeat biopsy. MATERIALS AND METHODS: Of men 103 underwent repeat biopsy after initial negative prostate biopsy, 55 men who had three or more serial PSA measurements until repeat biopsy were evaluated. PSA-DT was calculated using a log-linear regression model and compared with other PSA-related parameters. RESULTS: Prostate cancer was diagnosed in 22 patients (40.0%). Mean PSA-DT in 55 patients was 59.3 months. Comparing of repeat positive biopsy group and negative group, PSA density (PSAD) and PSA velocity (PSAV) in the positive biopsy group were significantly greater than in the negative biopsy group. Age, serum PSA concentration at initial and repeat biopsy, PSA adjusted for volume of transition zone (PSATZ), free to total PSA ratio (%F/T) did not recognize significant differences between both biopsy groups. PSA-DT of positive biopsy group (35.1 months) was significantly shorter than that of negative biopsy group (76.5 months). None was diagnosed prostate cancer whose PSA-DT was longer than 96 months. CONCLUSION: When we considered prostate repeat biopsy, it was thought that PSA-DT could be one important material, but it was limitation for indication as to other PSA-related parameters.     

214例前列腺穿刺结果的前列腺癌病灶分布情况分析

目的探讨经直肠超声引导下经直肠前列腺穿刺活检结果的前列腺癌病灶分布情况。方法本组214例,其中214例前列腺特异抗原＞4．0ng/ml 203例,直肠指诊可疑前列腺癌41例；均行13针前列腺穿刺活检术。入选病例的年龄为50～90岁,平均69．8岁；PSA水平0．8～112．3ng/ml,平均18．7 ng/ml；前列腺体积12．3～182．5ml,平均61．3 ml；直肠指诊阴性者173例,阳性者41例。分析各穿刺部位的阳性率。结果5区13针法的阳性率为36．0%(77/214)。前列腺各穿刺部位的阳性率为：底部48/214(22．4%)、中部57/214(26．6%)、尖部57/214(26．6%)、外侧底部47/214(22．0%)、外侧中部61/214(28．5%)。各穿刺部位的阳性率的差异具有显著性(P＜0．001)。结论前列腺穿刺活检发现的前列腺癌病灶分布不均匀。前列腺的尖部、中部和外侧中部的穿刺阳性率较其它部位高。     

Prospective evaluation of prostate cancer detection by prostate specific antigen related parameters: comparison in serum and plasma samples.

PURPOSE: We compared the usefulness of serum and plasma samples for enhancing the specificity of prostate cancer detection. MATERIALS AND METHODS: We analyzed receiver operating characteristics curves to evaluate prospectively the cancer detection performance of prostate specific antigen (PSA) related parameters derived from serum and plasma samples in 248 and 249 consecutive patients, respectively. RESULTS: Receiver operating characteristics curve analysis showed that PSA density and transition zone PSA density were more powerful predictors of prostate cancer than total or free PSA in the group overall at intermediate serum PSA 2.1 to 10 ng./ml. and in the subgroup with total PSA 4.1 to 10 ng./ml. regardless of digital rectal examination findings. Percent free PSA performed significantly better than total PSA in patients with serum total PSA 4.1 to 10 ng./ml. PSA density, transition zone PSA density and percent free PSA did not differ substantially in patients with serum total PSA 4.1 to 10 ng./ml. However, none of these parameters distinguished patients with prostate cancer from those with benign histology when PSA was in the lower range of 2.1 to 4 ng./ml. The performance of these parameters was worse when plasma sample data were used for calculation. CONCLUSIONS: The performance of percent free PSA appears at least comparable to that of PSA density and transition zone PSA density in patients in this cohort with serum total PSA 4.1 to 10 ng./ml. without regard to digital rectal examination. The poor performance of these parameters in the lower PSA range underscores the need for other parameters to improve the specificity of cancer detection in elderly Japanese males. Continued use of serum samples is justified for measuring PSA related parameters by current assay techniques.     

前列腺移行带特异抗原密度检测前列腺癌的临床观察

目的　评价前列腺移行带特异抗原密度 (PSAT)检测前列腺癌 (PCa)的临床价值。　方法　用酶免法测定 30例PCa及 88例良性前列腺增生症 (BPH)患者血清PSA水平 ,用经直肠前列腺B超测定患者总前列腺体积及移行带体积 ,并计算PSA密度 (PSAD)及PSAT值。　结果　PSA在 4～ 10ng/ml时 ,PCa和BPH患者PSAD值分别为 0 .2 6± 0 .11、0 .13± 0 .0 6 ,两组间相比差别具有显著性意义 (P <0 .0 1) ;PSAT值则分别为 1.0 4± 0 .70、0 .2 1± 0 .13 ,两组间相比差别具有显著性意义 (P <0 .0 1)。若选择PSAD =0 .15作为判断患者是否需穿刺活检的标准 ,将有 2 7%的PCa漏诊 ,而若选择PSAT =0 .35作为判断患者是否需穿刺活检的标准 ,只有 9%的PCa漏诊 (P <0 .0 1)。　结论　PSAT是一种新的有效的检测PCa的方法 ,PSA在 4～ 10ng/ml范围时 ,用PSAT检测PCa较用PSAD更精确。     

Evaluation of prostate specific antigen (PSA) adjusted to transition zone in prostatic cancer detection

ObjectiveTo investigate if PSA adjusted to transition zone (PSA-TZ) can be considered as a predictor parameter of cancer with better specificity or not than PSA, PSA density (PSAD) or PSA free/total ratio.Material and methodsData of 706 patients with sextant prostatic biopsies are analyzed in prospective way because of prostatic cancer suspicion. Range of PSA was between 4 to 20 ng/ml. Determination of PSA-TZ was calculated by dividing the PSA value by the volume of the transition zone of the prostate applying the ellipsoid formula and comparison of obtained results in detection of cancer was performed by ROC curves analysis for each one of PSA-related parameters.ResultsOf the total group of patients, in 199 cases (28.2%) prostatic cancer was detected. Analysis by ROC curves demonstrated than PSA-TZ and PSAD were better predictors of cancer than PSA free/total ratio and PSA (p<0.0001). The cutoff value of PSA-TZ of 0.18 ng/ml/cc was considered as the best, obtaining a 95% sensitivity and a 27% specificity. For this sensitivity, PSA, PSAD and PSA free/total ratio only obtained 5, 9 and 16% specificity respectively. Areas under curve (AUC) obtained for PSA, PSA free/total ratio, PSAD and PSA-TZ were 0.539, 0.612, 0.694 and 0.722 respectively.ConclusionsPSA-TZ in the studied population was a parameter with better diagnostic specificity than PSA, PSAD and PSA free/total ratio for the same 95% sensitivity. This would justify its utility in clinical paractice reducing the number of unnecesary biopsies.     

Obesity, serum prostate specific antigen and prostate size: implications for prostate cancer detection

PURPOSE: Obesity has been associated with lower serum testosterone, theoretically resulting in decreased PSA production. Obesity has also been associated with prostatic enlargement, making the detection of existent cancer more difficult. Together these findings would result in an apparent protective effect of obesity on prostate cancer risk due to technical detection issues unrelated to cancer biology. We examined the association between BMI, and PSA and prostate weight in a cohort of men undergoing RP. MATERIALS AND METHODS: We evaluated the association of BMI with prostate weight and PSA using linear regression, adjusting for patient age at RP, year of RP, race, and pathological stage and grade in 1,414 men treated with RP between 1988 and 2004 at the 5 equal access medical centers that comprise the Shared Equal Access Regional Cancer Hospital Database. RESULTS: On multivariate analysis increasing BMI was associated with increasing prostate weight but only in men younger than 63 years and not in men 63 years or older (p-trend <0.001 and 0.44, respectively). In men younger than 63 years mean multivariate adjusted prostate weight +/- SE in those with a BMI of less than 25 vs 30 to 34.9 kg/m was 33.8 +/- 1.4 vs 41.4 +/- 1.6 gm. There was no significant association between BMI and preoperative PSA (p-trend = 0.70). CONCLUSIONS: In a cohort of men undergoing RP obesity was associated with larger prostate size but only in younger men. There was no association between BMI and PSA. Assuming equal PSA, the degree of prostatic enlargement observed in younger obese men in this study would be expected to result in a modest decrease in the odds of detecting prostate cancer in a contemporary series of PSA screened men due to the decreased sensitivity of cancer detection related to larger prostate size. Obesity may appear protective for prostate cancer in younger men due to technical issues unrelated to cancer biology.