Prostatic volume and volume-adjusted prostate-specific antigen as predictive parameters for prostate cancer patients with intermediate PSA levels

The object of the study was to examine the usefulness of volume-adjusted prostate-specific antigen (PSA) parameters for prediction of prostate cancer in the patients with intermediate PSA levels. The subjects were 235 patients with intermediate PSA levels (range: 4.1-10.0 ng/ml) whose prostate volume (PV) and prostate transition zone volume (TZV) were evaluated between August 1996 and April 2004. PSA, PV, TZV, PSA density (PSAD) (PSA/PV) and PSA transition zone density (PSATZD) (PSA/TZV) were assessed with the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Simple and multivariate logistic regression analyses were used to analyze the odds ratios of age, PSA, PSAD, PSATZD, PV, TZV, digital rectal examination (DRE) and transrectal ultrasonography (TRUS) findings. Fifty-five patients (23.4%) of 235 patients had biopsy-proven prostate cancer. The univariate analysis revealed significant differences in the mean values of age, PSAD, PSATZD, PV, TZV and DRE between the patients with cancer and the non-cancer patients. The ROC curve analysis revealed that PV, TZV, PSAD and PSATZD had significant predictive values as compared with that of PSA. However, there was no difference in AUC between them. The stepwise logistic regression analysis showed that the age, PV, PSATZD and DRE had significant predictive values, and that PSATZD had the most predictive power. In conclusion, both PSAD and PSATZD had significant predictive values in discriminating prostate cancer. Furthermore, the stepwise logistic regression analysis showed that PSATZD had the strongest predictive value.     

Follow-up of men with elevated prostate-specific antigen and one set of benign biopsies at prostate cancer screening

OBJECTIVE: To study the follow-up of men with elevated prostate-specific antigen (PSA) (>3 ng/ml) after one benign set of sextant biopsies. From the G?teborg branch of the European Randomised Study of Screening for Prostate Cancer (ERSPC). METHOD: 456 men with one set of benign sextant biopsies were followed every second year for 4 years with PSA determinations. In cases of elevated PSA, transrectal ultrasound (TRUS) guided sextant biopsies were suggested. Digital rectal examination (DRE), prostate volume, PSA, PSA density (PSAD) and the ratio between free and total PSA (PSA F/T) were recorded. RESULTS: Complete data were available for 322 men. 3 groups were identified. In 84/322 (26%) men cancer was found ("cancer" group). 182/322 (56%) had benign biopsies ("benign" group) and 56/322 (17%) had normalised PSA ("normalised PSA" group). Median prostate volumes were 36, 46, and 33 cc respectively in the three groups. DRE and/or TRUS were abnormal in only 30% of the men in all groups. Cancer was not found in any prostate >70 cc volume. In prostates of <20 cc either cancer was found or PSA was normalised. The "normalised PSA" group had initial PSA, PSAD and PSA F/T similar to cancer, normalising during follow-up. CONCLUSIONS: Patients with one negative sextant biopsy still have a high likelihood of cancer, especially men with persistently elevated PSA and small prostates (<20 cc) while the majority of men with large prostates (>70 cc) have PSA elevation due to benign prostate hyperplasia (BPH) and not to cancer.     

Volume-adjusted prostate-specific antigen (PSA) variables in detecting impalpable prostate cancer in men with PSA levels of 2-4 ng/mL: transabdominal measurement makes a significant contribution

OBJECTIVE: To examine whether prostate-specific antigen (PSA) levels adjusted according to prostate volume improve prostate cancer detection using transrected biopsies in men with PSA levels of 2-4 ng/mL, and benign findings on a digital rectal examination (DRE). PATIENTS AND METHODS: Men aged < or = 79 years and with serum PSA levels of 2-4 ng/mL and normal DRE findings were prospectively enrolled. Eligible patients were recommended for transrectal prostate biopsies after measuring prostate volumes with transrectal (TRUS) and transabdominal (TAUS) ultrasonography, and transition zone volumes with TRUS. In addition to PSA levels and the free-to-total PSA ratio, volume-adjusted PSA levels, PSA densities determined by TRUS (PSAD(TRUS)), and TAUS (PSAD(TAUS)), and PSA transition zone densities (PSATzD) were compared using receiver operating characteristic analysis. RESULTS: Prostate cancer was diagnosed in 31 (22%) of the 139 men who had prostate biopsies. The area under the curve (AUC) of PSAD(TRUS) (0.796) and PSATzD (0.792) was similar and significantly greater than that of PSA (AUC 0.588) and the free-to-total PSA ratio (AUC 0.658). PSAD(TAUS) was a significantly better indicator of prostate cancer than PSA levels alone (P = 0.043). CONCLUSION: As predictors of prostate cancer, there were no significant differences between PSAD(TRUS) and PSATzD. Although PSAD(TAUS) was worse than PSA variables adjusted by total and transition zone prostate volumes determined by TRUS, it was a better predictor than the PSA value alone in men with a low PSA level. These results indicate that TAUS is worthwhile where the routine use of TRUS before biopsy is difficult.     

Evaluation of magnetic resonance imaging-based prostate-specific antigen density of the prostate in the diagnosis of prostate cancer

OBJECTIVES: We evaluated prostate-specific antigen (PSA) density of the prostatic volume (PSAD) estimated using transrectal ultrasonography (TRUS; TRUS-based PSAD), magnetic resonance imaging (MRI; MRI-based PSAD), and PSA density of the transition zone (TZ) volume (PSATZD) estimated using MRI (MRI-based PSATZD) in the diagnosis of prostate cancer (PCa). METHODS: One hundred and twenty patients, who were suspected to have PCa based on PSA, ranged between 4.1 and 20.0 ng/mL were enrolled in this study. RESULTS: The prostatic volume estimated using TRUS was smaller than the volume estimated using MRI by 11.4% in the patients with PSA levels ranging 4.1-20.0 ng/mL, 7.2% in those 4.1-10.0 ng/mL, and 15.7% in those 10.1-20.0 ng/mL, respectively. PSA levels were correlated with the prostatic volume estimated using TRUS and MRI, and TZ volume estimated using MRI in the patients without PCa; however, the level was not correlated with them in the patients with PCa. The area under the receiver operating characteristic curve of MRI-based PSAD was higher than that of TRUS-based PSAD; however, there was no statistical difference. Stepwise logistic regression analysis for the prediction of PCa by using PSA-related parameters confirmed that MRI-based PSATZD was the most significant predictor in patients with PSA levels in the range of 4.1-20.0 ng/mL (P < 0.001), the range of 4.1-10.0 ng/mL (P = 0.002), and the range of 10.1-20.0 ng/mL (P < 0.001), respectively. CONCLUSIONS: The prostatic volume estimated using TRUS was smaller than the volume estimated using MRI. MRI-based PSATZD is the most significant predictor in the four parameters.     

Community‐based prostate cancer screening in Japan: Predicting factors for positive repeat biopsy

Objectives: To assess possible predictors in determining criteria for repeat biopsy in a prostate cancer screening population. Methods: A total of 50 207 men over 55 years‐of‐age have participated in a prostate cancer screening program in Otokuni, Kyoto, Japan for 12 years. Transperineal systematic biopsy was carried out in case of positive digital rectal examination (DRE) or positive transrectal ultrasonography (TRUS) or a prostate‐specific antigen (PSA) value greater than 10.0 ng/mL. For those with a PSA level from 4.1 to 10.0 ng/mL, and negative DRE and TRUS findings, biopsy was indicated only when PSA density (PSAD) was greater than 0.15. The same indication was applied for the repeat biopsy. Results: A repeat biopsy after an interval of more than 2 years was carried out in 140 patients and was positive in 50 (36%) patients. The PSA value at the diagnosis of cancer declined from the initial value in six (12%) patients. On multivariate logistic regression analysis, PSA velocity (PSAV) as well as PSAD and DRE findings at latest screening were independent predictors for positive repeat‐biopsy outcome. The odds ratio (95% confidence intervals) of PSAV >0.48, latest PSAD >0.33 and positive latest DRE were 4.17 (1.05–18.5), 4.15 (1.31–14.0), and 3.62 (1.06–13.2), respectively. A combination of three variables defined as positive if any of these were positive, reduced 31% of unnecessary biopsies while missing 8% of low volume, low grade cancers. Conclusions: A combination of latest PSAD, PSAV and positive DRE at latest screening might help to reduce unnecessary repeat biopsies in high‐risk patients with an initial negative biopsy.     

Retrospective evaluation of PSA density for selection of biopsy candidates with prostate specific antigen in the gray zone

PURPOSE: We examined the usefulness of prostate specific antigen density (PSAD) for selection of biopsy candidate with prostate specific antigen levels between 4.1 and 10.0 ng./ml. in prostate cancer screening retrospectively. MATERIALS AND METHODS: The screening was conducted on male candidates in Natori city, aged 55 years or older, for 6 years from 1994 through 1999. We could analyze serum PSA levels and PSA density in 118 men with PSA levels between 4.1 and 10.0 ng./ml. All of 118 men underwent ultrasound guided systematic prostate biopsy regardless of findings of digital rectal examination and transrectal ultrasound. Prostate volume was estimated by transrectal ultrasound measurements using the prolate ellipse formula (pi/6 x length x width x height). PSAD was calculated by dividing serum PSA level by prostate volume. Serum PSA levels were determined by Tandem-R assay. RESULTS: In 118 men, twenty-five men had prostate cancer. There was no significant difference in mean PSA between those with prostate cancer and those without prostate cancer, but the difference was significant in the mean PSA density (mean 0.26 and 0.16, respectively, p < 0.0001). Receiver operating characteristic curves for PSA and PSAD demonstrated superior benefit for PSAD in 118 men. A sensitivity, a specificity, a positive predictive value and a negative predictive value of PSAD cut-off of 0.15 were 88%, 52.7%, 33.3% and 94.2%. PSAD cut-off of 0.18 showed the highest sum of sensitivity and specificity, which gave a sensitivity of 80%, a specificity of 72%, a positive predictive value of 43.5% and a negative predictive value of 93.1%. PSAD cut-off of 0.15 would seem to be preferable to cut-off of 0.18 because of less cancer missing. CONCLUSIONS: Although further studies are needed to determine optimal cut-off value to be used in clinical practice, PASD seems to be useful for the selection of biopsy candidates with PSA levels of 4.1 to 10.0 ng./ml. in the prostate cancer screening.     

Examination for indication of systematic biopsy for diagnosis of prostate cancer]

BACKGROUND: Systematic biopsy has been commonly used for detection of prostate cancer. Nevertheless, as this examination occasionally gives patients severe complications it is necessary to give careful consideration for application of this examination. Thus, we analyzed retrospectively 145 cases who underwent transrectal ultrasonography (TRUS) guided systematic biopsy to evaluate the application of systematic biopsy, correlating with the findings of digital rectal examination (DRE), prostate specific antigen (PSA), the findings of transrectal ultrasonography (TRUS) and the results of biopsies. METHODS: Between May, 1995 and May, 1997, 143 patients who were suspected to have prostate cancer with either of PSA and DRE, and 2 patients who received visual laser ablation of prostate (VLAP), underwent TRUS guided systematic biopsy of prostate. We evaluated diagnostic efficacy of PSA, DRE, TRUS, prostate-volume-specific PSA, and PSA density (PSAD). RESULTS: Sensitivity, specificity and positive predictive value (P.P.V.) are 78.4%, 62.8% and 53.5% for DRE, 100.0%, 4.4% and 41.8% for PSA, 88.2%, 60.0% and 52.9% for TRUS, 87.8%, 72.1% and 64.2% for prostate-volume-specific PSA, 100.0%, 30.6% and 45.4% for PSAD, respectively. Ten of 69 patients (14.5%) whose PSA levels were 4.0 to 10.0 ng/ml were diagnosed as cancer, and positive for both or either of DRE and TRUS. Twenty-seven who were negative for both of DRE and TRUS were not diagnosed as prostate cancer. Using the combination of prostate-volume-specific PSA, DRE and TRUS, we could eliminate 29 non-cancer men (21.5%) whose PSA level was greater than 4.0 ng/ml from systematic biopsy. CONCLUSION: On the diagnosis of prostate cancer, the combination of prostate-volume-specific PSA, DRE and TRUS is very useful to exclude unnecessary systematic biopsy, if an urologist could be used to and trained for DRE and TRUS.     

Prostate specific antigen density for discriminating prostate cancer from benign prostatic hyperplasia in the gray zone of prostate-specific antigen.

Serum prostate specific antigen (PSA) is currently the best blood marker for prostate cancer. However, low specificity for detection of prostate cancer, especially in the gray zone of PSA, is a problem. We evaluated the clinical significance of PSA density (PSAD) in gray zone PSA cases with conversion of serum PSA to a Stanford reference value. In a series of histologically confirmed 63 benign prostatic hyperplasia (BPH) patients and 234 prostate cancer patients, 36 BPH patients and 25 prostate cancer patients had gray zone PSA levels. Serum PSA was measured with the Markit-F or Markit-M PA assay. All data were converted to Stanford reference values. We used transabdominal ultrasound to determine prostate volume. PSAD was determined as the serum PSA/prostate volume ratio. The mean PSA values for BPH and prostate cancer were 6.42 +/- 1.80 and 7.80 +/- 2.15 ng/ml (p = 0.0116), respectively, and prostate volume was 33.4 +/- 14.1 ml and 17.1 +/- 8.2 ml, respectively (p < 0.0001). The mean PSAD for prostate cancer was 0.572 +/- 0.363 while that for BPH was 0.218 +/- 0.085 (p = 0.0001). Cut-off values with sensitivity > 90% were 0.218 for PSAD and 30 ml for prostate volume. At these cut-off values, specificity reached 56% for each marker. In discriminating prostate cancer from BPH in the gray zone of PSA, PSAD demonstrated better performance than PSA.     

Prostate cancer detection by prostate-specific antigen-related parameters

Total serum prostate-specific antigen (PSA) levels, free-to-total PSA ratio (F/T ratio) and PSA density (PSAD) were compared to clarify the clinical significance of these parameters in the diagnosis of prostate cancer (CaP) with intermediate PSA concentrations (4-10 ng/ml). PSAD and F/T ratio were obtained during the period from May 1999 to April 2001 from 43 patients with serum PSA concentrations of 4-10 ng/ml who underwent ultrasound-guided systematic sextant biopsies. PSAD was compared with total serum PSA and F/T ratio via receiver operating characteristic (ROC) curves for diagnosis of CaP. Diagnosis of CaP and non-CaP was made in 12 (27.9%) and 31 (72.1%) of the 43 patients, respectively. Mean serum PSA, PSA density and F/T ratio were 7.308 +/- 0.636 ng/ml, 0.271 +/- 0.039 ng/ml/cm3 and 16.225 +/- 4.911% in patients with CaP and 6.300 +/- 0.289 ng/ml, 0.178 +/- 0.020 ng/ml/cm3 and 15.213 +/- 0.980% in those with non-CaP, respectively. The ROC curve analysis demonstrated that PSAD predicted the biopsy outcome significantly better than F/T ratio and total PSA in all 43 patients (p < 0.05). In distinguishing CaP patients, the cutoff value of 0.16 ng/ml/cm3 for PSAD yielded a specificity level of 71.0% at a sensitivity level of 83.3%. Our study revealed that PSAD is a significant predictor in distinguishing CaP from non-CaP in Japanese men.     

Prostate biopsy in patients with long-term use of indwelling bladder catheter: What is the rationale?

ObjectiveAcute urinary retention (AUR) is expected to occur in 2% to 39% men with benign prostatic hyperplasia. To date, no study has elucidated the effect of long-term use of indwelling bladder catheter on serum prostate specific antigen (PSA) levels and on the incidence of prostate cancer (CaP). The aim of the present study is to analyze the incidence of CaP in patients with long-term use of indwelling bladder catheter and determine some practice patterns on this issue.Materials and methodsThe study comprised a retrospective analysis of data from 1,651 patients who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy from July 2004 to June 2009. Among these patients, 198 (12%) were using an indwelling bladder catheter during the biopsy for at least 1 month. The incidence of CaP was recorded according to total PSA levels. Other variables such patient age, free/total PSA rate, PSA density, prostate volume, and duration of catheter use was also analyzed. Men with a digital rectal examination suspicious for cancer were not considered for analysis.ResultsMedian patient age was 71 years (37 to 89 years). Overall, 25% of patients presented a CaP diagnosis. CaP incidence according to the PSA levels was 0%, 18.9%, 24.5%, and 40.6% for patients with PSA ≤4.0, 4.1–10.0, 10.1–20.0, and >20.0 ng/ml, respectively. When prostate volume was analyzed together, we demonstrated that only 1 (2.4%) patient with PSA below 10.0 ng/ml and prostate volume >60 g had CaP. Median total PSA, PSA density, and prostate volume were statistically different between patients with and without CaP.ConclusionsProstate biopsy should not be indicated for all patients with diagnosis of BPH and AUR who present an elevated PSA level. Patients with PSA below 10.0 ng/ml, and prostate volume >60 g should only undergo biopsy in selected cases. Patients with PSA >20.0 ng/ml and a prostate volume ≤60 g are at higher risk of CaP diagnosis.     

Predictive value of the international prostate symptom score for positive prostate needle biopsy in the low-intermediate prostate-specific antigen range

PURPOSE: Serum prostate-specific antigen (PSA) has a restricted predictive value for prostate cancer in the low-intermediate PSA range (2.5-10 ng/ml). Our aim was to determine the predictive value of the International Prostate Symptom Score (IPSS) for positive prostate needle biopsy (PNB) in patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy with a low-intermediate PSA level. PATIENTS AND METHODS: Between 2001 and 2004, the data of 389 consecutive patients applying for any urologic complaint to our department and who underwent TRUS-guided prostate biopsy due to an elevated serum PSA and/or abnormal digital rectal examination (DRE) were retrospectively analyzed. A total of 158 eligible patients with a low-intermediate PSA level were included in the study. The patient's age, PSA, free PSA, free/total PSA, prostate volume, PSA density (PSAD), pre-biopsy IPSS were compared in the positive and negative biopsy groups. RESULTS: Fifty-eight of 158 patients (37%) who underwent TRUS-guided prostate biopsy had positive PNBs. Forty-eight patients (30%) had abnormal DREs. In the positive PNB group, the mean age was older and PSAD was higher, but the means of the prostate volumes and total IPSS were lower (p<0.05). Multivariate analysis demonstrated that age and IPSS were independent predictors of a positive PNB (p<0.05). The odds ratio of mild IPSS for positive PNB controlled for age was 3.0 (95% CI 1.5-6.7). Receiver-operating characteristics analysis revealed a mild IPSS (AUC=0.640) and was a considerable predictor for positive PNB as well as PSAD (AUC=0.648). The sensitivity and specificity of IPSS with a cutoff value of 7.5 points were 31 and 87% for prediction of prostate cancer detection. CONCLUSION: In the low-intermediate PSA range, mild IPSS may be a predictive factor for positive PNB with a similar specificity of PSAD.     

Early detection of prostate cancer in the ESRD population

BACKGROUND: There are currently no prostate cancer screening guidelines specific to the end-stage renal disease (ESRD) population. With this in mind, we evaluated the clinical usefulness of digital rectal examination (DRE), serum total prostate-specific antigen (PSA), prostate-specific antigen density (PSAD) and transrectal ultrasound (TRUS) in predicting prostate cancer in men with ESRD. METHODS: Fifty male ESRD patients age 40 years and older with no prior history of prostate cancer were enrolled in the study. All patients underwent PSA measurement and a DRE followed by a TRUS. PSAD was calculated as the total PSA divided by the prostate volume. Ultrasound-guided prostate biopsies were performed on any patient with 1 or more of the following abnormal findings: a nodule detected on DRE; an abnormal TRUS; PSA > 4.0 ng/ml, or a PSAD > 0.15 ng/ml/cm3. RESULTS: Abnormal findings were detected in 19 patients. Two (4%) had an abnormal DRE, 3 (6%) had PSA > 4.0 ng/ml, 3 (6%) had PSAD > 0.15 ng/ml/cm3 and 16 (32%) had abnormal findings on TRUS. Three patients had 2 abnormal findings and 1 had 3. Of the 15 prostate biopsies performed, 4 (27%) revealed prostate cancer and 3 (20%) high-grade prostatic intraepithelial neoplasm (HGPIN) comprising 8% and 6%, respectively, of the studied population. Of the 4 patients diagnosed with prostate cancer, none had abnormal DRE, 2 (50%) had PSA > 4.0 ng/ml (sensitivity = 66.7% and PPV = 50% (p = 0.236)), 3 (75%) had PSAD > 0.15 ng/ml/cm3 (sensitivity = 100% and PPV = 75% (p < 0.018)), and 3 (75%) had abnormal findings on TRUS (sensitivity = 30% and PPV = 75% (p = 1.000)). CONCLUSION: Routine screening with PSA and DRE does not seem sensitive enough to predict the presence of the disease. Although TRUS detected abnormalities in 16 patients (32%), sensitivity was very low (30%). In our patients, PSAD increased the sensitivity and positive predictive value (PPV) of detecting prostate cancers compared to PSA alone.     

Predictive value of prostate specific antigen density in the detection of prostate cancer in patients with elevated prostate specific antigen levels and normal digital rectal findings or stage A prostate cancer

We compared the usefulness of PSA and PSA density (PSAD) in diagnosing prostate cancer in 102 men who had a PSA value higher than 4.0 ng/ml and normal digital rectal examination and who had undergone transrectal ultrasonography-guided systematic sextant biopsies of the prostate between August 1996 and October 1999. In addition, for a group of 53 patients who underwent retropubic simple prostatectomy, PSA, PSAD and PSA transition zone (PSA-TZ) examination results for those with stage A prostate cancer were compared with the results for those with benign prostatic hyperplasia (BPH). Of the former 102 men, 20 (19.6%) had prostate cancer. There was no significant difference in mean PSA level between patients with negative and those with positive biopsy results (mean 9.3 and 11.8, respectively, p = 0.295), but the mean PSAD of patients with positive biopsy results was significantly higher than that of those with negative results (mean 0.55 and 0.29, respectively, p = 0.0007). Of the 53 men who underwent retropubic simple prostatectomy, 10 (18.9%) were diagnosed with stage A prostate cancer. There was no significant difference in mean PSA, PSAD and PSA-TZ examination results between patients with BPH and those with stage A prostate cancer. For all 102 patients and for 71 patients with PSA levels of 4.1-10.0 ng/ml, a PSAD cutoff value of 0.1 reduced the number of biopsies 15.7% (16 of 102 cases), and 22.5% (16 of 71 cases), respectively. These results suggest that by measurement of PSAD some patients with benign disease could be spared a biopsy which would have been performed based on PSA results alone.     

Diagnostic value of prostate-specific antigen-related parameters in discriminating prostate cancer.

BACKGROUND: Using the percentage (of total) of free prostate-specific antigen (PSA) in discriminating prostate cancer (CaP) from benign prostate hyperplasia (BPH) has not been fully delineated in Japanese men. To clarify the clinical significance of percent free PSA, various parameters, including total prostate volume, percent free PSA, PSA density (PSAD) and PSA density of transition zone volume (PSAT), were compared. METHODS: Ninety-seven patients who had visited one of three community-based hospitals, and whose total PSA value ranged from 4 to 20 ng/mL were prospectively enrolled in this study. Fresh sera were applied to measure the percent free PSA. RESULTS: Of the 97 patients, CaP and BPH were diagnosed in 24 (25%) and 73 patients, respectively. In discriminating CaP patients, the cutoff values of 17% for percent free PSA, 0.3 ng/mL per cm3 for PSAT, and 0.19 ng/mL per cm3 for PSAD yielded specificity levels of 56, 40 and 58% at sensitivity levels of 92, 92 and 79%, respectively. As for the 65 patients with intermediate PSA, range 410 ng/mL, and normal digital rectal examination, the percent free PSA and total prostate volume statistically discriminated CaP patients from BPH patients. A multiple logistic regression model proved percent free PSA to be the only significant discriminating factor (P=0.045; odds ratio, 9.06). CONCLUSIONS: This prospective study revealed percent free PSA to be a significant useful predictor in discriminating CaP from BPH in Japanese men.     

以前列腺特异抗原水平分组筛查与前列腺穿刺阳性率的关系

目的探讨不同血清前列腺特异抗原(PSA)水平前列腺癌检出情况以及直肠指诊(DRE)、经直肠超声检查(TRUS)、PSA密度(PSAD)等指标对筛查前列腺穿刺活检病例的意义。方法回顾性分析在1996年4月至2002年12月间行TRUS引导前列腺6点系统穿刺活检的634例患者的诊断资料,对各PSA组(≤4.0,4.1~,10.1~和>20.0μg/L组)中前列腺癌的检出率,以及PSA、DRE、TRUS、PSAD等对前列腺癌的预测作用进行t检验、χ2检验和多因素Logistic回归分析。结果PSA≤4.0,4.1~,10.1~和>20.0μg/L各组的前列腺癌检出率分别为11.6%(17/146),26.8%(38/142),39.8%(68/171)和68.6%(120/175)。PSA的敏感性最高(93.0%),特异性低(33.0%);DRE、TRUS等诊断效率较低。随血清PSA水平升高,前列腺癌检出率以及DRE、TRUS的阳性预测值逐渐升高;在PSA4.1~20.0μg/L者中,PSAD对前列腺癌有较大的预测价值(OR=687.09±646.96,P=0.000)。以PSAD≥0.13μg.L-1.cm-3为截点筛查前列腺穿刺病例,可在不明显降低敏感性的基础上,减少阴性穿刺。结论各PSA组国人与欧美等国前列腺癌检出率有较大差别;DRE、TRUS的筛查作用与血清PSA水平有关;按PSA水平分组筛查穿刺病例,可提高前列腺穿刺的阳性率。     

Serum prostate-specific antigen as a predictor of prostate volume in men with benign prostatic hyperplasia

OBJECTIVES: To assess the utility of prostate-specific antigen (PSA) as a predictor of prostate volume by characterizing the relationship between prostate volume and serum PSA in men with symptomatic benign prostatic hyperplasia (BPH) and no evidence of prostate cancer, stratified by decade of life. METHODS: Placebo-controlled multicenter trials in patients with BPH and a safety study in normal young men provided baseline measurements of serum PSA and prostate volume. The analyses included patients with a baseline prostate volume measured by either transrectal ultrasound (TRUS) or magnetic resonance imaging and baseline serum PSA. A common central laboratory was used for all but one of the individual studies; both laboratories used the Hybritech method. Patients 80 years of age or older were excluded. Patients with a baseline serum PSA greater than 10 ng/mL were excluded to reduce the likelihood of including occult prostate cancer cases. The patients in the BPH trials were screened at baseline by digital rectal examination (DRE) and serum PSA. Those with suspicious findings underwent TRUS-guided biopsy; only patients with negative biopsies are included in these analyses. RESULTS: The analyses included 4627 patients, 4448 from the BPH trials and 179 from the safety study. The men in the BPH trials were older (mean age+SE, 63.7+0.10 years) than the men in the safety study (mean age + SE, 30.8+/-0.43), had larger prostates (mean volume+/-SE, 43.7+/-0.38 mL versus 26.3+/-0.49 mL in the safety study), and had higher serum PSA values (mean+/-SE, 2.6+/-0.03 ng/mL versus 0.7+/-0.39 ng/mL in the safety study). The relationship between prostate volume and serum PSA was evaluated using only the BPH trial data. Prostate volume and serum PSA have an age-dependent log-linear relationship (ie, their logarithms are linearly related, and the parameters of the relationship depend on age). Older men tend to have a steeper rate of increase in prostate volume with increasing serum PSA (P < 0.00 for differences between slopes), and there was a slight tendency for PSA density to increase with age. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of serum PSA to predict threshold prostate sizes in men with BPH. The ROC curve analyses revealed that PSA had good predictive value for assessing prostate volume, with areas under the curve ranging from 0.76 to 0.78 for various prostate volume cutoff points (30, 40, and 50 mL). Conclusions. Prostate volume is strongly related to serum PSA in men with BPH and no evidence of prostate cancer, and the relationship depends on age. Since treatment outcome or risk of long-term complications depend on baseline prostate volume, serum PSA can estimate the degree of prostate enlargement sufficiently accurately to be useful for therapeutic decision making. To achieve a specificity of 70% while maintaining a sensitivity between 65% and 70%, approximate age-specific criteria for detecting men with prostate glands exceeding 40 mL are PSA > 1.6 ng/mL, >2.0 ng/mL, and >2.3 ng/mL for men with BPH in their 50s, 60s, and 70s, respectively.     

Value of prostate volume measurement using transabdominal ultrasonography for the improvement of prostate-specific antigen-based cancer detection

PURPOSE: To examine value of prostate-speci fi c antigen (PSA) adjusted by prostate volume measured using transabdominal ultrasonography in prostate cancer detection among men with elevated PSA. METHODS: 238 men aged 79 years or younger with serum PSA levels of 2.0-20.0 ng/mL and normal digital rectal examination fi ndings were studied in terms of total and free PSA, prostate volumes with transrectal (TRUS) and transabdominal (TAUS) ultrasonography and transition zone volumes with TRUS prior to transrectal 10-core biopsy. In addition to sole PSA values and the free-to-total PSA ratio, volume-adjusted PSA values, PSA densities determined by TRUS (PSAD(TRUS)), and TAUS (PSAD(TAUS)), and PSA transition zone densities (PSATzD) were compared using receiver operating characteristic (ROC) analysis. RESULTS: Prostate cancer was diagnosed in 58 (24.4%) of the 238 men who underwent prostate biopsies. Of the areas under ROC curves (AUC) of studied parameters, PSATzD (AUC 0.751) was the best and signi fi cantly superior to PSAD(TAUS) (AUC 0.664, P = 0.007). However, PSAD(TAUS) exceeded PSA (AUC 0.559, P = 0.004) and showed potential capability of a one-fourth reduction in unnecessary biopsies without spoiling sensitivity (90%). Cancer detection rate was only 4.2% in the 48 patients whose prostate volume in TAUS was > 50 mL and PSAD(TAUS) was < 0.075. CONCLUSIONS: Since PSAD(TRUS) and PSATzD were signi fi cantly superior to PSAD(TAUS), TRUS is feasible as the standard fashion to determine prostate volume in the diagnosis of prostate cancers. However, TAUS is also worthwhile as it can improve the prostate cancer detection using sole PSA, and primary use of TAUS has the potential to reduce the substantial number of unnecessary biopsy safely.     

Serendipity in detecting disease in low prostate-specific antigen ranges

OBJECTIVE: To assess the magnitude of prostate cancer detection by serendipity (the coincidental detection of prostate cancer during the evaluation of an abnormal screening test result) when a digital rectal examination (DRE) and transrectal ultrasonography (TRUS) are used as initial screening tests for prostate cancer in men with low levels of prostate-specific antigen (PSA; 0.0-3.9 ng/mL). PATIENTS AND METHODS: In all, 117 participants of a population-based screening study were diagnosed with prostate cancer after a standard evaluation of an abnormal screening test result; 49 underwent radical prostatectomy. Serendipity was defined as either: (i) the presence of prostate cancer opposite to the side that raised suspicion for cancer on DRE and/or TRUS; (ii) a negative lesion-directed biopsy while cancer was present in one or more of the cores of the sextant biopsy; (iii) a tumour volume of < 0.5 mL on radical prostatectomy. RESULTS: Depending on the definition, 27-63% of prostate cancers detected at low PSA values were detected coincidentally and not as a result of a true-positive test result. The proportion of cancers detected by serendipity was inversely correlated with serum PSA level. CONCLUSION: A relatively high proportion of prostate cancers diagnosed in men with low PSA levels, and in which a biopsy was prompted by a suspicious DRE and/or TRUS, are considered to be detected by chance only. As these cancers are mostly small (< 0.5 mL), with potentially low biological aggressiveness, relying on serendipity seems disadvantageous in prostate-cancer screening. The level of serendipity in prostate cancer detection, the poor performance of the screening test, and high inter-observer variability, casts further doubt on the utility of DRE (and TRUS) as initial screening tests for prostate cancer in population-based screening.     

The value of prostatic specific antigen density in the early diagnosis of prostate cancer

In order to differentiate benign from malignant prostatic lesions, 42 patients were evaluated using the prostate specific antigen density (PSAD) test. All patients were evaluated with PSA determination, digital rectal examination (DRE), transrectal ultrasonography (TRUS) and ultrasound-guided prostatic biopsies. PSA was analyzed by the I-MX ABBOT assay. PSAD was determined by dividing the serum PSA by the volume of the prostate. Prostatic biopsies identified cancer in 3 of the 42 patients (6.38%). It is concluded that PSAD is valuable for the early diagnosis of localized prostatic carcinoma, especially when there are negative findings from DRE and/or TRUS.     

Changes in serum prostate-specific antigen following prostatectomy in patients with benign prostate hyperplasia

PURPOSE: To investigate how prostatectomy for patients with benign prostate hyperplasia (BPH) affected the serum prostate-specific antigen (PSA) levels. METHODS: In 193 patients who underwent prostatectomy for BPH, serum PSA levels were measured before and three months after the operation. The total prostate weight measured by transrectal ultrasonography (TRUS) and the weight of the surgical specimen were examined in relation to the pretreatment PSA value and the changes in PSA levels after the operation. RESULTS: The transition zone volume measured by TRUS could well estimate the weight of the surgical specimen in patients who underwent subcapsular prostatectomy and transurethral resection of the prostate. The concentration of preoperative serum PSA showed a significant correlation with the prostatic volume and with the transition zone volume. Removal of 1 g of BPH tissue reduced serum PSA levels by an average of 0.18 ng/mL. The change in serum PSA levels after the prostatectomy correlated with the total prostatic gland volume and with the transition zone volume. CONCLUSIONS: The elevated PSA levels in patients with BPH were caused by the enlargement of the transition zone. After the resection of the adenoma, PSA levels should be expected to decrease to the normal range.