Multicenter Optimization and Validation of a 2-Gene mRNA Urine Test for Detection of Clinically Significant Prostate Cancer before Initial Prostate Biopsy.

PURPOSE: A 2-gene, urine based molecular test that combines mRNA biomarkers with clinical factors can risk stratify patients for clinically significant prostate cancer. To ensure the generalizability of assay results we optimized and validated the clinical model for men with serum prostate specific antigen less than 10 ng/ml who were undergoing initial prostate biopsy. MATERIALS AND METHODS: Urine samples were collected from 1,955 men from The Netherlands, France and Germany prior to an initial prostate biopsy and study subjects were divided into training and validation cohorts. Urinary HOXC6 and DLX1 mRNA levels were quantified and RNA results were then combined with other risk factors in a clinical model optimized to detect ISUP (International Society of Urological Pathology) Grade Group 2 or greater prostate cancer in men with prostate specific antigen less than 10 ng/ml. Results in the validation cohort were compared with the PCPTRC (Prostate Cancer Prevention Trial Risk Calculator), version 2.0. RESULTS: The optimal clinical model included urinary HOXC6 and DLX1 mRNA levels, patient age, digital rectal examination and prostate specific antigen density (serum prostate specific antigen/prostate volume). In the 715 validation cohort subjects with prostate specific antigen less than 10 ng/ml the AUC was 0.82 with 89% sensitivity, 53% specificity and 95% negative predictive value. The PCPTRC AUC was 0.70. The full validation cohort of 916 men including all prostate specific antigen levels yielded an AUC of 0.85 with 93% sensitivity, 47% specificity and 95% negative predictive value. The PCPTRC AUC was 0.76. CONCLUSIONS: The 2-gene based urine assay, which is optimized for biopsy naïve patients with serum prostate specific antigen less than 10 ng/ml, demonstrated high sensitivity and negative predictive value to detect clinically significant prostate cancer. These data support using the test to help guide initial prostate biopsy decisions.

Clinically significant Prostate Cancer diagnosed using a urinary molecular biomarker-based risk score: two case reports.

BACKGROUND: Identifying men for a repeat prostate biopsy is a conundrum to urologists. Risk calculators (RCs) such as the European Randomized Study of Screening for Prostate Cancer (ERSPC) RCs have been developed to predict the outcome of prostate biopsies and have been shown to improve diagnostic accuracy compared to PSA alone. However, it was recently shown that the outcome for high-grade prostate cancer (PCa) upon biopsy tended to be underestimated in men with previous negative biopsies using ERSPC RC model 4. For these men, an individualized approach combining the clinical information with the outcome of biomarker-related urine tests may help to make a more informed decision. CASE PRESENTATION: Two men, aged 66 and 69 respectively when presented in the clinic, show the typical dilemma of urologist and patient for electing repeat prostate biopsy. Both men had normal DRE findings, did not have a family history of PCa, presented with serum PSA values between 3 and 10 ng/ml and the first biopsies were negative for disease. The ERSPC RC4 did not indicate a biopsy in these men. The urinary molecular biomarker-based test for HOXC6 and DLX1, combining biomarker-expression profiling with clinical risk factors, resulted in SelectMDx Risk scores for these men that were higher than the cut-off of the test. Based on this outcome, mpMRI was performed with an outcome of PI-RADS ≥4 in both men. Histopathological evaluation of TRUS-guided biopsies confirmed high-grade PCa. CONCLUSIONS: The urinary molecular biomarker-based risk score played a pivotal role in the diagnosis of clinically significant PCa whereas ERSPC RC4 outcome would not have indicated further diagnostic follow-up in these two cases. The timely diagnosis was shown to be crucial for the curative treatment by radical retropubic prostatectomy and the potential life-years gained for these two vital males.

Rational basis for the combination of PCA3 and TMPRSS2:ERG gene fusion for prostate cancer diagnosis.

BACKGROUND: The prostate cancer gene 3 (PCA3) and TMPRSS2:ERG gene fusion are promising prostate cancer (PCa) specific biomarkers. Our aim was to simultaneously quantify the expression levels of PCA3 and TMPRSS2:ERG in a panel of benign prostatic hyperplasia (BPH), normal prostate adjacent to PCa (NP) and PCa tissue samples, to provide a rational basis for the understanding of the false-positive and false-negative results of the urine assays. METHODS: The tissue samples were carefully histopathologically characterized to obtain homogeneous groups. The mRNA was isolated, transcribed into cDNA and the relative expressions of PCA3 and TMPRSS2:ERG were measured using a quantitative real-time polymerase chain reaction. The expression levels of PCA3 and TMPRSS2:ERG were compared between the different groups. RESULTS: We included 48 BPH, 32 NP, and 48 PCa. The PCA3 expression levels progressively increased from BPH to NP (3 times) and finally to PCa (30 times). There were one false-positive sample and seven false-negative samples. The TMPRSS2:ERG gene fusion was found in 8.3% of the BPH, 15.6% of the NP, and 50% of the PCa samples. The use of TMPRSS2:ERG in the PCA3 negative cases allowed diagnosis of four of the seven false-negative samples and added one false-positive, but we had to define a cut-off value to avoid eight false-positive results. CONCLUSIONS: Considering tissue expression of the markers, most of the false-negative results of the PCA3 test were corrected by TMPRSS2:ERG (57%) and the combination of both had a higher sensitivity for PCa diagnosis. Some of the control samples did express TMPRSS2:ERG and a cut-off value had to be defined to avoid false-positive results.

Recurrent gene fusions in prostate cancer: their clinical implications and uses.

Gene fusions, resulting from chromosomal rearrangements, have been attributed to leukaemias and soft tissue sarcomas. The recent discovery of a recurrent gene fusion TMPRSS2-ERG in approximately half of the prostate cancers tested indicates that gene fusions also play a role in the onset of common epithelial cancers. Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the Western male population. It is a heterogeneous disease, both in terms of pathology and clinical presentation. Since the discovery of the TMPRSS2-ERG fusion, other gene fusions have been reported, most of which result in the androgen-regulated over-expression of the oncogene ERG or other ETS transcription factors. The high prevalence of these gene fusions represents a distinct class of tumours, which may give more insight in the heterogeneity of the disease. These gene fusions are of interest as biomarkers for diagnosis of prostate cancer, and some of them could be useful in predicting the presence of aggressive disease. This review focuses on the biological significance and clinical implementation of gene fusions, and particularly the most commonly reported TMPRSS2-ERG fusion, in prostate cancer.

Biomarkers for the diagnosis of prostatic inflammation in benign prostatic hyperplasia.

BACKGROUND: Chronic prostatic inflammation could be a central mechanism in benign prostatic hyperplasia (BPH) progression. Currently, the histological examination of prostate biopsies remains the only way to diagnose prostatic inflammation. Our objective was to find new noninvasive biomarkers for the diagnosis of prostatic inflammation. METHODS: Ninety BPH samples were investigated in two steps. First, a hypothesis was generated using a profiling procedure with a panel of 96 genes on an initial set of 30 samples. Then, the candidate biomarkers were validated on a large number of samples (n = 90). Gene expression was compared with the histological prostatic inflammation score based on the density and the confluence of lymphoid nodules. Finally, protein transcripts of the candidate biomarkers were investigated in urine samples and compared with clinical data. RESULTS: Of the 96 genes, nine were significantly correlated with the inflammation score on the initial set of patients. Four of them were validated on the complete set of patients: CCR7, CD40LG, CTLA4, and ICOS. ICOS and CTLA4 protein levels were readily measured in urine samples using a conventional ELISA procedure. High-ICOS expression in urine was associated with a higher post-void residual and a lower maximum urinary flow rate. CONCLUSIONS: Four genes were significantly upregulated at the mRNA level in the prostate tissue of patients with severe inflammation score. Two proteins were measured in urine samples, and were associated with maximum uroflowmetry and post-void residual. A prospective clinical study is needed to confirm their clinical relevance.

Differential expression of PCA3 and its overlapping PRUNE2 transcript in prostate cancer.

BACKGROUND: PCA3 is one of the most prostate cancer (PrCa)-specific markers described so far. Recently, a new genomic structure of PCA3 as well as new flanking and overlapping gene transcripts has been identified. Furthermore, a co-regulation of PCA3 and its overlapping gene PRUNE2(BMCC1) has been suggested. Our aim was to assess the diagnostic performance of a new PCA3 isoform (PCA3-TS4) and to study the interactions between PCA3 and BMCC1 in PrCa. METHODS: We used SYBR Green quantitative (q)PCR with specific primers to compare PCA3 and BMCC1 expression of normal versus tumor tissue of human prostate. PCA3-TS4 plasmid was created to calculate the absolute amounts of PCA3 transcripts. The androgen regulation of PCA3 and BMCC1 expression was studied in LNCaP and 22Rv1 cells stimulated with 5alpha-dihydrotestosterone. RESULTS: We have not found any relevant diagnostic advantage of the PCA3-TS4 isoform over the "classical" PCA3 isoform in our group of PrCa patients. Additionally, PCA3-TS4 appears to be only a minor PCA3 transcript. We were also unable to confirm the hypothesis that BMCC1 isoforms are androgen-induced in vitro. CONCLUSIONS: Despite the presence of the recently identified marginal PCA3 transcripts in human PrCa, the previously described major PCA3 isoform still constitutes the best target for diagnostic purposes. PCA3 and BMCC1 are overlapping genes in reverse orientation that do not appear to be co-regulated.

Predictive value of PCA3 in urinary sediments in determining clinico-pathological characteristics of prostate cancer.

PURPOSE: PCA3 urine tests have shown to improve the specificity in prostate cancer (PCa) diagnosis, and have thus the potential to reduce the number of unnecessary prostate biopsies and to predict repeat biopsy outcomes. In this study, PCA3 was correlated with clinical stage, biopsy Gleason score (GS), radical prostatectomy GS, tumor volume, and pathological stage to assess its potential as predictor of PCa aggressiveness. METHODS: In this study, 351 men admitted for prostate biopsies based on serum PSA levels >3 ng/ml, an abnormal DRE, and/or a family history of PCa were included. Post-DRE urinary sediments from 336 men were tested using a transcription-mediated amplification-based PCA3 test, and assay results were correlated with clinical stage and biopsy GS. In a sub-cohort of 70 men who underwent radical prostatectomy, the PCA3 values were correlated to their radical prostatectomy GS, tumor volume, and pathological stage. RESULTS: In this patient cohort we could not find a correlation between clinical stage, biopsy GS, radical prostatectomy GS, tumor volume, and pathological stage. CONCLUSIONS: The predictive value of PCA3 for PCa aggressiveness features as reported in earlier studies cannot be confirmed in our study. Experimental differences (urine sediments vs. whole urine) and cohort may explain this. The exact place of PCA3 as prognostic test for PCa remains the subject of investigation.

Preliminary evaluation of the effect of dutasteride on PCA3 in post-DRE urine sediments: a randomized, open-label, parallel-group pilot study.

BACKGROUND: Dutasteride is commonly used in patients that are also at risk for prostate cancer (PCa). Therefore, the influence of dutasteride on PCa markers has to be studied. To date, only the effect of dutasteride on serum prostate-specific antigen (PSA) has been studied. This was the first study to investigate the effect of dutasteride on the new PCa marker PCA3, longitudinally and in a dose dependent manner. METHODS: From April 25, 2005 to October 31, 2006, 16 subjects with benign prostatic hyperplasia (BPH) and 9 subjects with clinically localized PCa were enrolled at the urological outpatient clinics of one university hospital and one community hospital. Eight subjects with BPH and five with PCa received 0.5 mg dutasteride once daily for 3 months, eight with BPH and four with PCa received 3.5 mg. No subjects were withdrawn because of adverse effects. RESULTS: In all four groups both 0.5 and 3.5 mg dutasteride had a variable effect on the PCA3 score. In contrast, its other effects were consistent as it rapidly reduced serum DHT by >or=90%, over time increased serum T by 20-30%, over time halved serum PSA and decreased prostate volume by 10-16%. CONCLUSIONS: In this exploratory/pilot study the effect of dutasteride on the PCA3 score was variable. This should be taken into account while using PCA3 in diagnostics. As this study was exploratory, the influence of androgen-deprivation therapy on the PCA3 score should be analyzed further.

Urinary Molecular Biomarker Test Impacts Prostate Biopsy Decision Making in Clinical Practice.

INTRODUCTION: There is an unmet need for noninvasive methods to better identify patients at increased risk for clinically significant prostate cancer. SelectMDx® is a molecular urine test validated for the detection of Gleason score 7 and higher cancers (ISUP [International Society of Urological Pathology] Grade Group 2-5). In this multicenter trial we evaluated the test's impact on prostate biopsy decision making in clinical practice. METHODS: The study involved 5 U.S. community urology practices which sequentially enrolled 418 patients who received a SelectMDx test between May 2016 and April 2017 while undergoing evaluation for initial prostate biopsy. All tests were ordered by the urologist for patient management. We determined biopsy and prostate cancer detection rates in patients with SelectMDx positive versus SelectMDx negative results. RESULTS: Of the 418 subjects evaluated with SelectMDx 253 (61%) had negative results and 165 (39%) had positive results. Subsequent biopsy rates for SelectMDx positive and negative cases were 60% (99) and 12% (32), respectively (p <0.001). Time from SelectMDx result to biopsy was shorter for those with positive vs negative results (median 2 vs 5 months, p=0.001). Of patients who underwent biopsy within 3 months of testing 71 (43%) with positive results underwent biopsy and 27 had cancers identified, including 10 greater than Grade Group 2. Of 9 patients with SelectMDx negative results (3.6%) who underwent biopsy 4 were diagnosed with cancer, all Grade Group 2 or less. CONCLUSIONS: SelectMDx had a significant impact on initial prostate biopsy decision making. Biopsy rates in SelectMDx positive cases were fivefold higher than in SelectMDx negative cases. These results describe the clinical utility of SelectMDx in real-world community urology practice.

Cost-effectiveness of SelectMDx for prostate cancer in four European countries: a comparative modeling study.

BACKGROUND: Low specificity of prostate-specific antigen results in a considerable number of unnecessary prostate biopsies in current practice. SelectMDx® predicts significant prostate cancer upon biopsy and is used to reduce the number of unnecessary initial prostate biopsies. Furthermore, potential overtreatment of insignificant prostate cancer can be reduced. Besides the diagnostic accuracy of the test, also the context in a specific country determines the potential health benefit and cost-effectiveness. Therefore, the health benefit and cost-effectiveness of SelectMDx were assessed in France, Germany, Italy, and Spain. SUBJECT AND METHODS: A decision model was used to compare the current standard of care in which men undergo initial prostate biopsy in case of an elevated prostate-specific antigen, to a strategy in which SelectMDx was used to select men for biopsy. Model inputs most relevant to each of the four countries were obtained. With use of the model long-term quality-adjusted life years (QALYs) and healthcare costs were calculated for both strategies. RESULTS: In all four countries, the SelectMDx resulted in QALY gain and cost savings compared with the current standard of care. In France, SelectMDx resulted in 0.022 QALYs gained and cost savings of €1217 per patient. For Germany, the model showed a QALY gain of 0.016 and a cost saving of €442. In Italy, the QALY gain and cost savings were 0.031 and €762. In Spain 0.020 QALYs were gained and €250 costs were saved. CONCLUSIONS: The results of the model showed that with SelectMDx, QALYs could be gained while saving healthcare costs in the initial diagnosis of prostate cancer. The significant presence of overtreatment in the current standard of care in all four countries was the main factor that resulted in the beneficial outcomes with SelectMDx.

Detection of TMPRSS2-ERG fusion transcripts and prostate cancer antigen 3 in urinary sediments may improve diagnosis of prostate cancer.

PURPOSE: Early detection of prostate cancer can increase the curative success rate for prostate cancer. We studied the diagnostic usefulness of TMPRSS2-ERG fusion transcripts as well as the combination of prostate cancer antigen 3 (PCA3) RNA and TMPRSS2-ERG fusion transcripts in urinary sediments after digital rectal examination (DRE). EXPERIMENTAL DESIGN: A total of 78 men with prostate cancer-positive biopsies and 30 men with prostate cancer-negative biopsies were included in this study. After DRE, the first voided urine was collected, and urinary sediments were obtained. We used semiquantitative reverse transcription-PCR (RT-PCR) analysis followed by Southern blot hybridization with a radiolabeled probe for the detection TMPRSS2-ERG fusion transcripts in these urinary sediments. A quantitative RT-PCR assay for PCA3 was used to determine the PCA3 score in the same sediments. RESULTS: TMPRSS2-ERG fusion transcripts can be detected in the urine after DRE with a sensitivity of 37%. In this cohort of patients, the PCA3-based assay had a sensitivity of 62%. When both markers were combined, the sensitivity increased to 73%. Especially in the cohort of men with persistently elevated serum prostate-specific antigen levels and history of negative biopsies, the high positive predictive value of 94% of TMPRSS2-ERG fusion transcripts could give a better indication which patients require repeat biopsies. CONCLUSION: In this report, we used for the first time the combination of the prostate cancer-specific biomarkers TMPRSS2-ERG and PCA3, which significantly improves the sensitivity for prostate cancer diagnosis.

The time-resolved fluorescence-based PCA3 test on urinary sediments after digital rectal examination; a Dutch multicenter validation of the diagnostic performance.

PURPOSE: To improve the specificity in prostate cancer diagnosis and to prevent unnecessary prostate biopsies, especially in the serum prostate-specific antigen (PSA) "gray zone" between 3 and 15 ng/mL, the implementation of prostate cancer-specific markers is urgently needed. The recently discovered prostate cancer antigen 3 (PCA3) is such a promising prostate cancer marker. In a previous single institution study, the PCA3 urine test clearly proved to be of diagnostic value. Therefore, the diagnostic performance of the PCA3 urine test was validated in a multicenter study. EXPERIMENTAL DESIGN: The first voided urine after digital rectal examination was collected from a total of 583 men with serum PSA levels between 3 and 15 ng/mL who were to undergo prostate biopsies. We determined the PCA3 score in these samples and correlated the results with the results of the prostate biopsies. RESULTS: A total of 534 men (92%) had an informative sample. The area under the receiver-operating characteristic curve, a measure of the diagnostic accuracy of a test, was 0.66 for the PCA3 urine test and 0.57 for serum PSA. The sensitivity for the PCA3 urine test was 65%, the specificity was 66% (versus 47% for serum PSA), and the negative predictive value was 80%. CONCLUSIONS: In this multicenter study, we validated the diagnostic performance of the PCA3 urine test in the largest group studied thus far using a PCA3 gene-based test. This study shows that the PCA3 urine test, when used as a reflex test, can improve the specificity in prostate cancer diagnosis and could prevent many unnecessary prostate biopsies.

DD3(PCA3), a very sensitive and specific marker to detect prostate tumors.

We identified DD3(PCA3) as one of the most prostate cancer-specific genes at present (M. J. Bussemakers et al. Cancer Res., 59: 5975-5979, 1999). Consequently, DD3(PCA3) is an interesting candidate for use as a diagnostic and/or prognostic marker. In this study we developed a method for the accurate quantification of DD3(PCA3) mRNA, using real-time quantitative reverse transcription-PCR. DD3(PCA3) was expressed at low levels in normal prostate but not in 21 selected other normal tissues, blood, or 39 tumor samples other than prostate. The diagnostic and prognostic value of DD3(PCA3) in normal, hyperplastic, and malignant prostate tissues was determined and compared with another promising tumor marker for prostate cancer, telomerase reverse transcriptase (hTERT gene), the expression of which is related to telomerase activity. Sensitivity and specificity estimates for both genes were calculated as the area under the receiver-operating characteristics curve (AUC-ROC). DD3(PCA3) (AUC-ROC, 0.98) demonstrated better diagnostic efficacy than hTERT (AUC-ROC, 0.88). Moreover, the median increase in mRNA expression in tumor tissues compared with nonmalignant prostate tissues was much higher for DD3(PCA3) (34-fold) than for hTERT (6-fold). In tumor tissues, the median expression of DD3(PCA3) was much higher than hTERT (5849 versus 10 normalized mRNA copies). A significant relationship was observed only between tumor stage and hTERT gene expression. We conclude that expression of the DD3(PCA3) gene is a very sensitive and specific marker for the detection of prostate tumor cells in a high background of normal (prostate) cells. Consequently, DD3 measurements may be used for clinical application in prostate needle biopsies or bodily fluids such as blood, ejaculate, urine, or prostate massage fluid.

Detection of High-grade Prostate Cancer Using a Urinary Molecular Biomarker-Based Risk Score.

BACKGROUND: To reduce overdiagnosis and overtreatment, a test is urgently needed to detect clinically significant prostate cancer (PCa). OBJECTIVE: To develop a multimodal model, incorporating previously identified messenger RNA (mRNA) biomarkers and traditional risk factors that could be used to identify patients with high-grade PCa (Gleason score ≥7) on prostate biopsy. DESIGN, SETTING, AND PARTICIPANTS: In two prospective multicenter studies, urine was collected for mRNA profiling after digital rectal examination (DRE) and prior to prostate biopsy. The multimodal risk score was developed on a first cohort (n=519) and subsequently validated clinically in an independent cohort (n=386). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The mRNA levels were measured using reverse transcription quantitative polymerase chain reaction. Logistic regression was used to model patient risk and combine risk factors. Models were compared using the area under the curve (AUC) of the receiver operating characteristic, and clinical utility was evaluated with a decision curve analysis (DCA). RESULTS AND LIMITATIONS: HOXC6 and DLX1 mRNA levels were shown to be good predictors for the detection of high-grade PCa. The multimodal approach reached an overall AUC of 0.90 (95% confidence interval [CI], 0.85-0.95) in the validation cohort (AUC 0.86 in the training cohort), with the mRNA signature, prostate-specific antigen (PSA) density, and previous cancer-negative prostate biopsies as the strongest, most significant components, in addition to nonsignificant model contributions of PSA, age, and family history. For another model, which included DRE as an additional risk factor, an AUC of 0.86 (95% CI, 0.80-0.92) was obtained (AUC 0.90 in the training cohort). Both models were successfully validated, with no significant change in AUC in the validation cohort, and DCA indicated a strong net benefit and the best reduction in unnecessary biopsies compared with other clinical decision-making tools, such as the Prostate Cancer Prevention Trial risk calculator and the PCA3 assay. CONCLUSIONS: The risk score based on the mRNA liquid biopsy assay combined with traditional clinical risk factors identified men at risk of harboring high-grade PCa and resulted in a better patient risk stratification compared with current methods in clinical practice. Therefore, the risk score could reduce the number of unnecessary prostate biopsies. PATIENT SUMMARY: This study evaluated a novel urine-based assay that could be used as a noninvasive diagnostic aid for high-grade prostate cancer (PCa). When results of this assay are combined with traditional clinical risk factors, risk stratification for high-grade PCa and biopsy decision making are improved.

Identification of a Candidate Gene Panel for the Early Diagnosis of Prostate Cancer.

PURPOSE: Serum PSA (sPSA) testing has led to the identification of patients with indolent prostate cancer, and inevitably overtreatment has become a concern. Progensa PCA3 urine testing was shown to improve the diagnosis of prostate cancer, but its diagnostic value for aggressive prostate cancer is limited. Therefore, urinary biomarkers that can be used for prediction of Gleason score ≥7 prostate cancer in biopsies are urgently needed. EXPERIMENTAL DESIGN: Using gene expression profiling data, 39 prostate cancer biomarkers were identified. After quantitative PCR analysis on tissue specimens and urinary sediments, eight promising biomarkers for the urinary detection of prostate cancer were selected (ONECUT2, HOXC4, HOXC6, DLX1, TDRD1, NKAIN1, MS4A8B, PPFIA2). The hypothesis that biomarker combinations improve the diagnostic value for aggressive prostate cancer was tested on 358 urinary sediments of an intention-to-treat cohort. RESULTS: A urinary three-gene panel (HOXC6, TDRD1, and DLX1) had higher accuracy [area under the curve (AUC), 0.77; 95% confidence interval (CI), 0.71-0.83] to predict Gleason score ≥7 prostate cancer in biopsies compared with Progensa PCA3 (AUC, 0.68; 95% CI, 0.62-0.75) or sPSA (AUC, 0.72; 95% CI, 0.65-0.78). Combining the three-gene panel with sPSA further improved the predictive accuracy (AUC, 0.81; 95% CI, 0.75-0.86). The accuracy of the three-gene predictive model was maintained in subgroups with low sPSA concentrations. CONCLUSIONS: The urinary three-gene panel (HOXC6, TDRD1, and DLX1) represents a promising tool to identify patients with aggressive prostate cancer, also in those with low sPSA values. The combination of the urinary three-gene panel with sPSA bears great potential for the early diagnosis of patients with clinically significant prostate cancer.

Applicability of biomarkers in the early diagnosis of prostate cancer.

Early diagnosis of prostate cancer can increase the curative success rate for this disease. Although serum prostate-specific antigen measurement is regarded as the best conventional tumor marker available, there is little doubt that it has great limitations. The threshold above which biopsies are indicated has now decreased to a serum prostate-specific antigen value of 3 ng/ml, which results in a negative biopsy rate of 70-80%. This can readily be explained by the fact that prostate-specific antigen is not specific for prostate cancer. Clinicians need more sensitive tools to help diagnose prostate cancer and monitor progression of the disease. Molecular oncology is playing an increasing role in the fields of diagnosis and therapy for prostate cancer and has already been instrumental in elucidating many of the basic mechanisms underlying the development and progression of this disease. The identification of new prostate cancer-specific genes, such as DD3PCA3, would represent a considerable advance in the improvement of diagnostic tests for prostate cancer. This could subsequently lead to a reduction of the number of unnecessary biopsies.

Prostate cancer antigen 3: diagnostic outcomes in men presenting with urinary prostate cancer antigen 3 scores ≥100.

OBJECTIVE: To describe the results of 3 rounds of diagnostic testing and linkage to the Dutch Cancer Registry for men with an initial prostate cancer antigen 3 (PCA3) score ≥100. METHODS: Within an earlier reported comparative study of PCA3 vs prostate-specific antigen in a prescreened population, 90 men with a PCA3 score ≥100 were identified and underwent biopsy, 28 prostate cancers (PCs) were found, 62 men remained at risk of a diagnosis of PC. All men were offered repeat testing; 6 PCs were found in 20 men at rebiopsy. Men with at least 1 negative biopsy (n = 56) were invited to undergo magnetic resonance imaging (MRI) studies and MRI-guided biopsies if indicated. Linkage to the Dutch Cancer Registry after 2.8 years of follow-up was performed for men with negative biopsies. RESULTS: Of the 56 men at risk, 28 agreed to participate in further testing. They were offered MRI studies; only 7 men agreed, and in 2, suspicious lesions were found and biopsies carried out. Only 1 PC was diagnosed and classified as T1c, Gleason 3 + 3 = 6. The overall findings of 3 rounds of testing and of linkage to the cancer registry show that eventually 35 PCs were detected in 90 men with PCA3 scores ≥100 (positive predictive value 38.9%). CONCLUSION: Finding no PC despite extended diagnostic efforts in many men with initial PCA3 scores ≥100 is unexpected and might be clinically relevant.

Prospective multicentre evaluation of PCA3 and TMPRSS2-ERG gene fusions as diagnostic and prognostic urinary biomarkers for prostate cancer.

BACKGROUND: Prostate cancer antigen 3 (PCA3) and v-ets erythroblastosis virus E26 oncogene homolog (TMPRSS2-ERG) gene fusions are promising prostate cancer (PCa) specific biomarkers that can be measured in urine. OBJECTIVE: To evaluate the diagnostic and prognostic value of Progensa PCA3 and TMPRSS2-ERG gene fusions (as individual biomarkers and as a panel) for PCa in a prospective multicentre setting. DESIGN, SETTING, AND PARTICIPANTS: At six centres, post-digital rectal examination first-catch urine specimens prior to prostate biopsies were prospectively collected from 497 men. We assessed the predictive value of Progensa PCA3 and TMPRSS2-ERG (quantitative nucleic acid amplification assay to detect TMPRSS2-ERG messenger RNA [mRNA]) for PCa, Gleason score, clinical tumour stage, and PCa significance (individually and as a marker panel). This was compared with serum prostate-specific antigen and the European Randomised Study of Screening for Prostate Cancer (ERSPC) risk calculator. In a subgroup (n=61) we evaluated biomarker association with prostatectomy outcome. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Univariate and multivariate logistic regression analysis and receiver operating curves were used. RESULTS AND LIMITATIONS: Urine samples of 443 men contained sufficient mRNA for marker analysis. PCa was diagnosed in 196 of 443 men. Both PCA3 and TMPRSS2-ERG had significant additional predictive value to the ERSPC risk calculator parameters in multivariate analysis (p<0.001 and resp. p=0.002). The area under the curve (AUC) increased from 0.799 (ERSPC risk calculator), to 0.833 (ERSPC risk calculator plus PCA3), to 0.842 (ERSPC risk calculator plus PCA3 plus TMPRSS2-ERG) to predict PCa. Sensitivity of PCA3 increased from 68% to 76% when combined with TMPRSS2-ERG. TMPRSS2-ERG added significant predictive value to the ERSPC risk calculator to predict biopsy Gleason score (p<0.001) and clinical tumour stage (p=0.023), whereas PCA3 did not. CONCLUSIONS: TMPRSS2-ERG had independent additional predictive value to PCA3 and the ERSPC risk calculator parameters for predicting PCa. TMPRSS2-ERG had prognostic value, whereas PCA3 did not. Implementing the novel urinary biomarker panel PCA3 and TMPRSS2-ERG into clinical practice would lead to a considerable reduction of the number of prostate biopsies.

Urinary biomarkers for prostate cancer: a review.

Although the routine use of serum prostate-specific antigen (PSA) testing has undoubtedly increased prostate cancer (PCa) detection, one of its main drawbacks is its lack of specificity. As a consequence, many men undergo unnecessary biopsies or treatments for indolent tumours. PCa-specific markers are needed for the early detection of the disease and the prediction of aggressiveness of a prostate tumour. Since PCa is a heterogeneous disease, a panel of tumour markers is fundamental for a more precise diagnosis. Several biomarkers are promising due to their specificity for the disease in tissue. However, tissue is unsuitable as a possible screening tool. Since urine can be easily obtained in a non-invasive manner, it is a promising substrate for biomarker testing. This article reviews the biomarkers for the non-invasive testing of PCa in urine.

Performance of the prostate cancer antigen 3 (PCA3) gene and prostate-specific antigen in prescreened men: exploring the value of PCA3 for a first-line diagnostic test.

BACKGROUND: The performance characteristics of serum prostate-specific antigen (PSA) as a diagnostic test for prostate cancer (PCa) are poor. The performance of the PCa antigen 3 (PCA3) gene as a primary diagnostic is unknown. OBJECTIVE: Assess the value of PCA3 as a first-line diagnostic test. DESIGN, SETTING AND PARTICIPANTS: Participants included men aged 63-75 who were invited for rescreening in the period from September 2007 to February 2009 within the European Randomised Study of Screening for Prostate Cancer, Rotterdam section. INTERVENTIONS: Lateral sextant biopsies were performed if the serum PSA value was > or =3.0 ng/ml and/or the PCA3 score was > or =10. MEASUREMENTS: Measurements included distribution and correlation of PSA value and PCA3 score and their relation to the number of cases and the characteristics of PCa detected. Additional value of PCA3 was included in men with previous negative biopsy and/or PSA <3.0 ng/ml. RESULTS AND LIMITATIONS: In 721 men, all biopsied, 122 PCa cases (16.9%) were detected. Correlation between PSA and PCA3 is poor (Spearman rank correlation: ρ=0.14; p<0.0001). A PSA > or =3.0 ng/ml misses 64.7% of the total PCa that can be detected with the sextant biopsy technique and 57.9% of serious PCa (T2a or higher and/or Gleason grade > or =4, n=19), and 68.2% of biopsies could have been avoided; the respective data for PCA3 > or =35 are 32%, 26.3%, and 51.7%. Performance of PCA3 in men with low PSA (area under the curve [AUC]: 0.63) and/or previous negative biopsy (AUC: 0.68) is unclear but has limited reliability due to small numbers. CONCLUSIONS: PCA3 as a first-line screening test shows improvement of the performance characteristics and identification of serious disease compared with PSA in this prescreened population.