A multi-institutional prospective trial in the USA confirms that the 4Kscore accurately identifies men with high-grade prostate cancer

A urine-based Exosomal gene expression test stratifies risk of high-grade prostate Cancer in men with prior negative prostate biopsy undergoing repeat biopsy

Background

Initial prostate biopsy often fails to identify prostate cancer resulting in patient anxiety, especially when clinical features such as prostate specific antigen (PSA) remain elevated, leading to the need for repeat biopsies. Prostate biomarker tests, such as the ExoDx™ Prostate (IntelliScore), or EPI test, have been shown to provide individualized risk assessment of clinically significant prostate cancer at initial biopsy; however, the performance in the repeat biopsy setting is not well established.

Methods

As part of a previous prospective clinical validation study evaluating the performance of the EPI test, we collected first-catch, non-DRE urine samples across 22 sites from men with at least one prior negative biopsy scheduled to undergo a repeat prostate biopsy to rule out prostate cancer. All men were 50 years or older with a PSA 2–10 ng/mL. Exosomal mRNA was extracted and expression of three genomic markers, PCA3, ERG and SPDEF was measured. The resulting EPI score was correlated with biopsy results.

Results

229 men with a prior negative biopsy underwent repeat biopsies. ExoDx Prostate demonstrated good performance ruling out high-grade (Grade group 2, GG2, or higher) prostate cancer (HGPCa) using the previously validated 15.6 cut point in the initial biopsy setting. The EPI test yielded an NPV of 92% independent of other clinical features and would have avoided 26% of unnecessary biopsies while missing only five patients with HGPCa (2.1%). Furthermore, the EPI test provided additional information at a cut-point of 20 and 29.6 with an NPV of 94%, potentially delaying 35 and 61% of unnecessary biopsies, respectively. AUC curves and Net Health Benefit Analyses demonstrated superior performance of ExoDx Prostate over PSA and clinical only risk calculators, i.e. ERSPC.

Conclusions

The EPI test provided good performance using the 15.6 cut-point for ruling out HGPCa / GG2 or higher in men undergoing a repeat prostate biopsy with a PSA of 2–10 ng/ml. Furthermore, the test utilizes gene expression data independent of clinical features to predict the likelihood of HGPCa / GG2 on a subsequent needle biopsy.

Impact of the MyProstateScore (MPS) Test on the Clinical Decision to Undergo Prostate Biopsy: Results From a Contemporary Academic Practice

OBJECTIVE

To evaluate the association of the MyProstateScore (MPS) urine test on the decision to undergo biopsy in men referred for prostate biopsy in urology practice.

METHODS

MPS testing was offered as an alternative to immediate biopsy in men referred to the University of Michigan for prostate biopsy from October 2013 through October 2016. The primary endpoint was the decision to perform biopsy. The proportion of patients undergoing biopsy was compared to predicted risk scores from the Prostate Cancer Prevention Trial risk calculator (PCPTrc). Analyses were stratified by the use of multiparametric magnetic resonance imaging (mpMRI). The associations of PCPTrc, MPS, and mpMRI with the decision to undergo biopsy were explored in a multivariable logistic regression model.

RESULTS

Of 248 patients, 134 (54%) proceeded to prostate biopsy. MPS was significantly higher in biopsied patients (median 29 vs14, P < .001). The use of biopsy was strongly associated with MPS, with biopsy rates of 26%, 38%, 58%, 90%, and 85% in the first through fifth quintiles, respectively (P < .001). MPS association with biopsy persisted upon stratification by mpMRI. On multivariable analysis, MPS was strongly associated with the decision to undergo biopsy when modeled as both a continuous (odds ratio [OR] 1.05, 95%; confidence interval [CI] 1.04-1.08; <.001) and binary (OR 7.76, 95%; CI 4.14-14.5; P < .001) variable.

CONCLUSION

Many patients (46%) undergoing clinical MPS testing as an alternative to immediate prostate biopsy were able to avoid biopsy. Increasing MPS was strongly associated with biopsy rates. These findings were robust to use of mpMRI.

Modern biomarkers in prostate cancer diagnosis

INTRODUCTION

The most common malignant neoplasm of the urinary tract is prostate cancer (PCa), which is a heterogeneous disease, ranging from very slowly developing and slightly benign to progressing, aggressive, metastatic and fatal, even when properly treated. Existing, imperfect diagnostic methods often lead to over-diagnosis and over-treatment of PCa. That is why new, better PCa biomarkers are being developed.

MATERIAL AND METHODS

This review summarizes the current results of the most promising and clinically used PCa biomarkers, as well as having the potential to create new diagnostic and prognostic tools, based on the Web of Science (www.apps.webofknowledge.com) and Scopus (www.scopus) databases. com).

RESULTS

Limited specificity of the prostate-specific antigen (PSA) test brings a need to develop new and better diagnostic tools. In the last few years, new approaches for providing significantly better biomarkers, an alternative to PSA, have been introduced. Modern biomarkers show improvement in being used as not only a diagnostic procedure, but also for staging, evaluating aggressiveness and managing the therapeutic process. We describe the methods recommended in the diagnosis of PCa and new PCa molecular diagnostics technologies. Individual biomarkers are used in various stages of the PCa diagnostic process, which was presented on the developed diagnostic flowchart describing the role of biomarkers in prostate cancer management.

CONCLUSIONS

Given the diverse nature of PCa, one diagnostic test will not answer all questions, so the use of several diagnostic methods will allow physicians to provide patients with better, personalized clinical advice.

Prespecified 4-Kallikrein Marker Model at Age 50 or 60 for Early Detection of Lethal Prostate Cancer in a Large Population Based Cohort of Asymptomatic Men Followed for 20 Years

PURPOSE

A prespecified statistical model based on 4 kallikrein markers in blood, commercially available as the 4Kscore®, has been shown to accurately detect high grade (greater than Grade Group 2) prostate cancer in men with moderately elevated prostate specific antigen. We assessed whether the model predicted prostate cancer metastasis or death in men not subject to prostate specific antigen screening.

MATERIALS AND METHODS

The cohort includes 43,692 unscreened prostate cancer-free men from a Swedish population based cohort with low rates of prostate specific antigen screening (Västerbotten Intervention Project). Using cryopreserved blood collected at ages 50 and 60 years from men in this cohort we analyzed the association between prostate specific antigen and other kallikrein marker levels in blood and risk of prostate cancer metastasis or death.

RESULTS

There were 308 with metastases and 172 prostate cancer deaths. Baseline prostate specific antigen was strongly associated with 20-year risk of prostate cancer death (c-index at age 50, 0.859, 95% CI 0.799-0.916; age 60, 0.840, 95% CI 0.799-0.878). Men 60 years old with prostate specific antigen below median (less than 1.2 ng/ml) had 0.4% risk of prostate cancer death at 20 years. Among men with moderately elevated prostate specific antigen (2.0 ng/ml or greater) the 4Kscore markedly improved discrimination (c-index 0.767 vs 0.828 and 0.774 vs 0.862 in men age 50 and 60, respectively). Long-term risk of prostate cancer death or metastasis in men with low 4Kscores was very low.

CONCLUSIONS

Screening should focus on men in top prostate specific antigen quartile at age 60 years. Men with elevated prostate specific antigen but a low 4Kscore can safely be monitored with repeated blood markers in place of immediate biopsy.

A discussion on controversies and ethical dilemmas in prostate cancer screening

Prostate cancer (PCa) is one of the the most common cancers in men. A blood test called prostate-specific antigen (PSA) has a potential to pick up this cancer very early and is used for screening of this disease. However, screening for prostate cancer is a matter of debate. Level 1 evidence from randomised controlled trials suggests a reduction in cancer-specific mortality from PCa screening. However, there could be an associated impact on quality of life due to a high proportion of overdiagnosis and overtreatment as part of the screening. The US Preventive Services Task Force (USPSTF) in 2012 recommended that PSA-based PCa screening should not to be offered at any age. However, considering the current evidence, USPSTF recently revised its recommendation to offer the PSA test to men aged 55-69 years with shared decision-making, in line with earlier guidelines from the American Cancer Society and the American Urological Association. A shared decision making is necessary since the PSA test could potentially harm an individual. However, the literature suggests that clinicians often neglect a discussion on this issue before ordering the test. This narrative discusses the main controversies regarding PCa screening including the PSA threshold for biopsy, the concept of overdiagnosis and overtreatment, the practical difficulties of active surveillance, the current level 1 evidence on the mortality benefit of screening, and the associated pitfalls. It offers a detailed discussion on the ethics involved in the PSA test and highlights the barriers to shared decision-making and possible solutions.

Initial experience with SelectMDx® in the diagnosis of prostate cancer in a real-world evidence clinical practice setting

INTRODUCTION

The use of biomarkers in the detection of prostate cancer (PC) can decrease overdiagnosis and overtreatment of non-significant PC. We analyze the usefulness and applicability of the SelectMDx® marker in a routine clinical practice setting.

MATERIAL AND METHODS

Retrospective study of 48 patients evaluated by the SelectMDx® test between July 2017 and April 2019. Patients were stratified into two groups according to the risk estimated by the clinically significant CP test (CS-PC): <2% or 'very low risk', and >2%. Results were expressed based on previous prostate biopsy (PB) and multi-parametric magnetic resonance imaging (mpMRI) outcomes.

RESULTS

Patients with negative PB and normal/doubtful mpMRI had <2% risk in 7/9 cases. Patients without PB and normal/doubtful mpMRI had <2% risk in 12/18 cases, and 2/6 cases with a >2% risk presented CS-PC. Of the 14 patients with no previous PB or mpMRI, 9 had <2% risk, and 2 cases were diagnosed with PC from the group of patients (5) with risk >2%. The number of patients in the remaining subgroups is too small to draw any conclusions. In all cases with pathological digital rectal examination, the test showed a >2% PC risk.

CONCLUSION

SelectMDx® is a promising test for detecting patients with a very low risk of CS-PC, especially in patients with suspected PC, with or without negative PB, with normal/doubtful mpMRI. The presence of a pathological digital rectal examination may condition the result of the test.

The Percentage of Free PSA and Urinary Markers Distinguish Prostate Cancer from Benign Hyperplasia and Contribute to a More Accurate Indication for Prostate Biopsy

The main advantage of urinary biomarkers is their noninvasive character and the ability to detect multifocal prostate cancer (CaP). We have previously implemented a quadruplex assay of urinary markers into clinical practice (PCA3, AMACR, TRPM8 and MSMB with KLK3 normalization). In this study, we aimed to validate it in a larger cohort with serum PSA 2.5-10 ng/mL and test other selected transcripts and clinical parameters, including the percentage of free prostate-specific antigen (PSA) (% free PSA) and inflammation. In the main cohort of 299 men, we tested the quadruplex transcripts. In a subset of 146 men, we analyzed additional transcripts (CD45, EPCAM, EZH2, Ki67, PA2G4, PSGR, RHOA and TBP). After a prostate massage, the urine was collected, RNA isolated from a cell sediment and qRT-PCR performed. Ct values of KLK3 (i.e., PSA) were strongly correlated with Ct values of other genes which play a role in CaP (i.e., PCA3, AMACR, TRPM8, MSMB and PSGR). AMACR, PCA3, TRPM8 and EZH2 mRNA expression, as well as % free PSA, were significantly different for BPH and CaP. The best combined model (% free PSA plus PCA3 and AMACR) achieved an AUC of 0.728 in the main cohort. In the subset of patients, the best AUC 0.753 was achieved for the combination of PCA3, % free PSA, EPCAM and PSGR. PCA3 mRNA was increased in patients with inflammation, however, this did not affect the stratification of patients indicated for prostate biopsy. In conclusion, the percentage of free PSA and urinary markers contribute to a more accurate indication for prostate biopsy.

Clinical Applications of Molecular Biomarkers in Prostate Cancer

There is clinically relevant molecular heterogeneity in prostate cancer (PCa), but this biological diversity has had only a minimal impact on clinical practice. Treatment outcomes in patients with localised PCa are often highly variable, even among patients stratified to the same risk group or disease state based on standard clinical and pathological parameters. In recent years, the development of gene panels has provided valuable data on the differential expression of genes in patients with PCa. Nevertheless, there is an urgent need to identify and validate prognostic and predictive biomarkers that can be applied across clinical scenarios, ranging from localised disease to metastatic castration-resistant PCa. The availability of such tools would allow for precision medicine to finally reach PCa patients. In this review, we evaluate current data on molecular biomarkers for PCa, with an emphasis on the biomarkers and gene panels with the most robust evidence to support their application in routine clinical practice.

Decision Tree Analysis for Prostate Cancer Prediction in Patients with Serum PSA 10 ng/ml or Less

Serum prostate-specific antigen (PSA) testing increases the number of persons who undergo prostate biopsy. However, the best possible strategy for selecting patients for prostate biopsy has not yet been defined. The aim of this study was to develop a classification and regression tree (CART) decision model that can be used to predict significant prostate cancer (PCa) in the course of prostate biopsy for patients with serum PSA levels of 10 ng/ml or less.

The following clinicopathological characteristics of patients who had undergone ultrasound-guided transrectal prostate biopsy were collected: age, PSA, digital rectal examination, volume of the prostate, and PSA density (PSAD). CART analysis was carried out by using all predictors. Different aspects of the predictive performances of the prediction model were assessed.

In this retrospective study, significant PCa values were detected in 26 (26.8%) of a total of 97 patients. The CART model had three branching levels based on PSAD as the most decisive variable and age. The model sensitivity was 73.1%, the specificity was 80.3% and the accuracy was 78.3%. Our model showed an area under the receiver operating characteristic curve of 82.6%. The model was well calibrated.

In conclusion, CART analysis determined that PSAD was the key parameter for the identification of patients with a minimal risk for positive biopsies. The model showed a good discrimination capacity that surpassed individual predictors. However, before recommending its use in clinical practice, an evaluation of a larger and more complete database is necessary for the prediction of significant PCa.

A pre-specified model based on four kallikrein markers in blood improves predictions of adverse pathology and biochemical recurrence after radical prostatectomy

Background

A pre-specified model based on four kallikrein markers in blood, commercially available as 4Kscore, predicts Gleason Grade (GG) 3 + 4 or higher prostate cancer on biopsy. However, sampling error and variation in pathology reporting may miss aggressive disease.

Methods

The 4Kscore was measured in cryopreserved blood from 2330 men obtained before prostatectomy at a single institution between 2002 and 2010. Adverse surgical pathology and biochemical recurrence (BCR) were pre-specified to be assessed in all men, biopsy GG 3 + 3, and 3 + 4.

Results

Adjusted for established clinical predictors, the 4Kscore was significantly associated with adverse pathology (OR 1.49; 95% CI 1.32, 1.67; p < 0.0001). Adding 4Kscore increased discrimination from (AUC) 0.672 to 0.718 and 0.644 to 0.659 within biopsy GG 3 + 3 and 3 + 4, respectively. Higher 4Kscore was associated with higher risk of BCR (HR 1.16, 95% CI 1.06, 1.26; p = 0.001). Adding 4Kscore improved the prediction of BCR (C-index 0.630–0.660) within GG 3 + 3, but not GG 3 + 4.

Conclusions

The 4Kscore can help guide the clinical decision whether additional risk assessment—such as confirmatory biopsy—is needed to decide between active surveillance versus curative therapy. Evidence that the panel could influence management in biopsy GG 3 + 4 is less strong and requires further investigation.

The Four-Kallikrein Panel Is Effective in Identifying Aggressive Prostate Cancer in a Multiethnic Population

BACKGROUND

The four-kallikrein (4K) panel has been demonstrated to improve prediction of aggressive prostate cancer compared with prostate-specific antigen (PSA) among men with moderately elevated PSA levels. However, the development and testing of the 4K panel has been conducted primarily in White men, with limited data in African Americans and no studies in other racial and ethnic groups.

METHODS

We evaluated the 4K panel in a nested case-control study among African American, Latino, Japanese, Native Hawaiian, and White men in the Multiethnic Cohort. Prediagnostic blood levels of free, intact, and total PSA and human kallikrein-related peptidase 2 were measured among 1,667 incident prostate cancer cases and 691 controls with PSA ≥2 ng/mL. We evaluated the discriminative ability of the 4K panel within and across all racial/ethnic groups.

RESULTS

The 4K panel enhanced discrimination of overall prostate cancer compared with free plus total PSA and total PSA alone (AUC 0.748 vs. 0.711 and 0.669, respectively). Discrimination was further enhanced for Gleason 8+ prostate cancer, aggressive prostate cancer, and death due to prostate cancer, and to a lesser degree for nonaggressive prostate cancer. Improvement of the 4K panel over PSA was observed in each population. Adding a prostate cancer polygenic risk score slightly improved upon the discriminative ability of the 4K panel.

CONCLUSIONS

The superior discriminative ability of the 4K panel over PSA for overall and aggressive prostate cancer across multiethnic populations indicates the broad clinical applicability of the 4K panel.

IMPACT

Our multiethnic investigation suggests potential for the 4K panel to improve current prostate cancer screening practices.

Detection and Prognosis of Prostate Cancer Using Blood-Based Biomarkers

Prostate cancer (PCa) is second only to lung cancer as a cause of death. Clinical assessment of patients and treatment efficiency therefore depend on the disease being diagnosed as early as possible. However, due to issues regarding the use of prostate-specific antigen (PSA) for screening purposes, PCa management is among the most contentious of healthcare matters. PSA screening is problematic primarily because of diagnosis difficulties and the high rate of false-positive biopsies. Novel PCa biomarkers, such as the Prostate Health Index (PHI) and the 4Kscore, have been proposed in recent times to improve PSA prediction accuracy and have shown higher performance by preventing redundant biopsies. The 4Kscore also shows high precision in determining the risk of developing high-grade PCa, whereas elevated PHI levels suggest that the tumor is aggressive. Some evidence also supports the effectiveness of miRNAs as biomarkers for distinguishing PCa from benign prostatic hyperplasia and for assessing the aggressiveness of the disease. A number of miRNAs that possibly act as tumor inhibitors or oncogenes are impaired in PCa. These new biomarkers are comprehensively reviewed in the present study in terms of their potential use in diagnosing and treating PCa.

A comparison of prostate health index, total PSA, %free PSA, and proPSA in a contemporary US population-The MiCheck-01 prospective trial

BACKGROUND

Increasing numbers of patients are presenting with aggressive prostate cancer (CaP); therefore, there exists a need to optimally identify these patients pre-biopsy.

OBJECTIVES

To compare the accuracy of total prostate specific antigen (PSA), %free PSA, and prostate health index (PHI) to differentiate between patients without CaP, with non-aggressive (Gleason 3 + 3, non-AgCaP) and with aggressive (Gleason ≥ 3 + 4, AgCaP) in a contemporary US population.

DESIGN, SETTINGS, AND PARTICIPANTS

Serum samples were collected from 332 US patients scheduled for biopsy due to an elevated age-adjusted PSA. Site and Central biopsy pathologic assessment were performed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Testing of PSA, free PSA, proPSA, and PHI was performed along with central pathology review. Test performance using logistic regression analysis for differentiating CaP from non-CaP as well as non-AgCaP from AgCaP was evaluated.

RESULTS AND LIMITATIONS

Central pathology review resulted in 32 upgrades including 14 Gleason 3 + 3 scores being upgraded to AgCaP with final distribution of 148 no-CaP, 64 non-AgCaP, and 120 AgCaP patients. Receiver operator curve (ROC) analysis of the different tests showed that PHI performed best at differentiating CaP from no-CaP subjects (area under the receiver operator curve 0.79). In contrast, the different tests were essentially equivalent in differentiating AgCaP vs. non-AgCaP.

CONCLUSIONS

In this recent US study of prebiopsy patients we observed a high proportion of AgCaP patients consistent with previous studies in contemporary US populations. Central Gleason review is recommended for multi-institutional studies comparing biomarkers. PHI was superior to PSA, free PSA, %free PSA, and proPSA in detecting CaP in this population but was not superior at differentiating AgCaP from non-AgCaP.

Concordance and Performance of 4Kscore and SelectMDx for Informing Decision to Perform Prostate Biopsy and Detection of Prostate Cancer

OBJECTIVES

To compare both the concordance between the 4Kscore and SelectMDx for informing decision to perform prostate biopsy (PB) and the performance of these tests for detecting clinically significant prostate cancer (csPCa). Several biomarkers were developed to inform decisions whether to perform a PB based on the probability of detecting csPCa. There is a paucity of studies directly comparing them METHODS: Between 11/2018 and 4/2019, all new referrals with the diagnosis of elevated PSA were advised to undergo 4Kscore and SelectMDx in order to guide the selection of candidates for PB. Men were advised to undergo PB if the reported biomarker risk for detecting csPCA was ≥7.5%, or if they presented a Prostate Image Reporting and Data System ≥1 MRI. Cohen's Kappa was used to assess the concordance between the binary 4Kscore and SelectMDx results using externally validated cutoffs of 7.5% and 12%. Receiver operating characteristics curve and area under the curve (AUC) assessed the performance of each biomarker for distinguishing csPCa.

RESULTS

Of 128 consecutive patients referred, 114 (89.1%) underwent 4Kscore and SelectMDx. The kappa coefficient between the biomarkers using the 7.5% cutoff was 0.184 (poor concordance) and 0.22 using the 12% cutoff. The two biomarkers yielded discordant guidance whether to proceed with PB in 46% and 38% of cases, respectively. csPCa was found in 22 of the 50 patients who underwent PB (44%). The AUC for 4Kscore and SelectMDx was 0.830 (95% confidence interval [CI]: 0.710 - 0.949) and 0.672 (95%CI: 0.517 - 0.828; P = .036) for csPCa, respectively.

CONCLUSION

The discordance observed between the 4Kscore and SelectMDx is disconcerting. The 4Kscore when combined with magnetic resonance imaging was superior to the SelectMDx for detecting csPCa. Prospective comparative studies must be performed to optimize implementation of biomarkers for selecting candidates for PB.

Early Diagnosis of Prostate Cancer from the Perspective of Chinese Physicians

Prostate cancer (PCa) is the seventh most diagnosed cancer and the tenth leading cause of cancer mortality in China. Unlike the USA, both incidence and mortality continue to increase. In China, PCa is often diagnosed at a locally advanced or metastatic stage, resulting in a high mortality-to-incidence ratio. Implementing regular screening using a well-validated biomarker may result in the earlier diagnosis of localized disease. Furthermore, it is important to be able to distinguish between low-grade and high-grade disease, to avoid subjecting patients to unnecessary biopsies, undertreatment of significant disease, or overtreatment of indolent disease. While prostate-specific antigen (PSA) is commonly used in PCa screening around the world, its relationship to PCa is still unclear and results vary widely across different studies. New biomarkers, imaging techniques and risk predictive models have been developed in recent years to improve upon the accurate detection of high-grade PCa. Blood- and urine-based biomarkers, such as PSA isoforms, prostate cancer antigen 3, or mRNA transcripts, have been used to improve the detection of high-grade PCa. These markers have also been used to create risk predictive models, which can further improve PCa detection. Furthermore, multiparametric magnetic resonance imaging is becoming increasingly accessible for the detection of PCa. Because of ethnic variations, biomarkers and risk predictive models validated in Western populations cannot be directly applied to Chinese men. Validation of new biomarkers and risk predictive models in the Chinese population may improve PCa screening and reduce mortality of this disease in China.

Towards personalized prostate cancer screening

The value of the prostate-specific antigen (PSA) in prostate cancer (PCa) screening is controversial. Contradictory results have been reported in the literature as to whether PSA-based screening reduces mortality. Also, some of the studies published are methodologically flawed. However, evidence consistently demonstrates that screening programs results in the identification of patients with indolent prostatic tumors which rate has increased. Controversy is not only about the value of PSA-based screening, but also about the age range for screening, risk groups based on baseline PSA, PSA ranges, or the use of other biomarkers (PHI, 4Kscore). At present, PCa screening in the general population is not recommended by most scientific societies, although it can be used after discussing the risks and benefits with the patient. When discussing the need to perform a screening, the risks of using screening (lack of specificity of PSA, overdiagnosis) must be weighed against the risks of not performing it (increased rate of patients with initial diagnosis of metastasis). In the recent years, a number of authors have advocated the use of personalized screening, which could change the risk/benefit evaluation, thereby making screening necessary on the basis of a set of individual factors.

Merging new-age biomarkers and nanodiagnostics for precision prostate cancer management

The accurate identification and stratified treatment of clinically significant early-stage prostate cancer have been ongoing concerns since the outcomes of large international prostate cancer screening trials were reported. The controversy surrounding clinical and cost benefits of prostate cancer screening has highlighted the lack of strategies for discriminating high-risk disease (that requires early treatment) from low-risk disease (that could be managed using watchful waiting or active surveillance). Advances in molecular subtyping and multiomics nanotechnology-based prostate cancer risk delineation can enable refinement of prostate cancer molecular taxonomy into clinically meaningful and treatable subtypes. Furthermore, the presence of intertumoural and intratumoural heterogeneity in prostate cancer warrants the development of novel nanodiagnostic technologies to identify clinically significant prostate cancer in a rapid, cost-effective and accurate manner. Circulating and urinary next-generation prostate cancer biomarkers for disease molecular subtyping and the newest complementary nanodiagnostic platforms for enhanced biomarker detection are promising tools for precision prostate cancer management. However, challenges in merging both aspects and clinical translation still need to be overcome.

Platelet-to-lymphocyte ratio and systemic immune-inflammation index versus circulating prostate cells to predict significant prostate cancer at first biopsy

OBJECTIVE

It has been reported that the systemic immune-inflammation index (SII) and platelet-to-lymphocyte ratio (PLR) are higher in men with prostate cancer. We compare their use with the percentage of free prostate-specific antigen (PSA), PSA density, and primary circulating prostate cells (CPCs) to predict clinically significant prostate cancer at first biopsy in men with a PSA of 4-10 ng/mL.

MATERIAL AND METHODS

Consecutive men with suspicion of prostate cancer underwent a 12-core transrectal ultrasound-guided prostate biopsy; total serum PSA, the percentage of free PSA, prostate ultrasound to calculate PSA density, and absolute neutrophil, lymphocyte, and platelet counts were used for risk assessment. CPCs were detected using differential gel centrifugation and immunocytochemistry with anti-PSA and anti-P504S. A malignant CPC was defined as a cell-expressing PSA and P504S and defined as positive or negative. Biopsies were classified as indicating cancer or no cancer. Areas under the curve for each parameter were calculated and compared, and diagnostic yields were calculated.

RESULTS

A total of 1223 men participated, and 467 (38%) had a biopsy positive for cancer, whereas 353/467 (76%) had clinically significant prostate cancer. The PLR was significantly higher in men with prostate cancer; there was no significant difference for the SII. The areas under the curves were CPC 0.84, the percentage of free PSA was 0.79, PLR 0.65, PSA density 0.62, and SII 0.46. Neither the PLR nor the SII discriminated between patients with clinically significant prostate cancer, indolent cancer, and benign prostatic disease.

CONCLUSION

Based on the results of this study, neither the SII nor PLR could differentiate between clinically significant prostate cancer and indolent cancer/benign disease at initial biopsy.

Multi-omic serum biomarkers for prognosis of disease progression in prostate cancer

Background

Predicting the clinical course of prostate cancer is challenging due to the wide biological spectrum of the disease. The objective of our study was to identify prostate cancer prognostic markers in patients ‘sera using a multi-omics discovery platform.

Methods

Pre-surgical serum samples collected from a longitudinal, racially diverse, prostate cancer patient cohort (N = 382) were examined. Linear Regression and Bayesian computational approaches integrated with multi-omics, were used to select markers to predict biochemical recurrence (BCR). BCR-free survival was modeled using unadjusted Kaplan–Meier estimation curves and multivariable Cox proportional hazards analysis, adjusted for key pathologic variables. Receiver operating characteristic (ROC) curve statistics were used to examine the predictive value of markers in discriminating BCR events from non-events. The findings were further validated by creating a training set (N = 267) and testing set (N = 115) from the cohort.

Results

Among 382 patients, 72 (19%) experienced a BCR event in a median follow-up time of 6.9 years. Two proteins—Tenascin C (TNC) and Apolipoprotein A1V (Apo-AIV), one metabolite—1-Methyladenosine (1-MA) and one phospholipid molecular species phosphatidic acid (PA) 18:0-22:0 showed a cumulative predictive performance of AUC = 0.78 [OR (95% CI) = 6.56 (2.98–14.40), P < 0.05], in differentiating patients with and without BCR event. In the validation set all four metabolites consistently reproduced an equivalent performance with high negative predictive value (NPV; > 80%) for BCR. The combination of pTstage and Gleason score with the analytes, further increased the sensitivity [AUC = 0.89, 95% (CI) = 4.45–32.05, P < 0.05], with an increased NPV (0.96) and OR (12.4) for BCR. The panel of markers combined with the pathological parameters demonstrated a more accurate prediction of BCR than the pathological parameters alone in prostate cancer.

Conclusions

In this study, a panel of serum analytes were identified that complemented pathologic patient features in predicting prostate cancer progression. This panel offers a new opportunity to complement current prognostic markers and to monitor the potential impact of primary treatment versus surveillance on patient oncological outcome.

Association of Baseline Prostate-Specific Antigen Level With Long-term Diagnosis of Clinically Significant Prostate Cancer Among Patients Aged 55 to 60 Years: A Secondary Analysis of a Cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

IMPORTANCE

The use of prostate-specific antigen (PSA) screening for prostate cancer is controversial because of the risk of overdiagnosis and overtreatment of indolent cancers. Optimal screening strategies are highly sought.

OBJECTIVE

To estimate the long-term risk of any prostate cancer and clinically significant prostate cancer based on baseline PSA levels among men aged 55 to 60 years.

DESIGN, SETTING, AND PARTICIPANTS

This secondary analysis of a cohort in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial uses actuarial analysis to analyze the association of baseline PSA levels with long-term risk of any prostate cancer and of clinically significant prostate cancer among men aged 55 to 60 years enrolled in the screening group of the trial between 1993 and 2001.

EXPOSURE

Single PSA measurement at study entry.

MAIN OUTCOMES AND MEASURES

Long-term risk of any prostate cancer and clinically significant prostate cancer diagnoses.

RESULTS

There were 10 968 men aged 55 to 60 years (median [interquartile range] age, 57 [55-58] years) at study enrollment in the screening group of the PLCO Cancer Screening Trial who had long-term follow-up. Actuarial 13-year incidences of clinically significant prostate cancer diagnosis among participants with a baseline PSA of 0.49 ng/mL or less was 0.4% (95% CI, 0%-0.8%); 0.50-0.99 ng/mL, 1.5% (95% CI, 1.1%-1.9%); 1.00-1.99 ng/mL, 5.4% (95% CI, 4.4%-6.4%); 2.00-2.99 ng/mL, 10.6% (95% CI, 8.3%-12.9%); 3.00-3.99 ng/mL, 15.3% (95% CI, 11.4%-19.2%); and 4.00 ng/mL and greater, 29.5% (95% CI, 24.2%-34.8%) (all pairwise log-rank P ≤ .004). Only 15 prostate cancer-specific deaths occurred during 13 years of follow-up, and 9 (60.0%) were among men with a baseline PSA level of 2.00 ng/mL or higher.

CONCLUSIONS AND RELEVANCE

In this secondary analysis of a cohort from the PLCO Cancer Screening Trial, baseline PSA levels among men aged 55 to 60 years were associated with long-term risk of clinically significant prostate cancer. These findings suggest that repeated screening can be less frequent among men aged 55 to 60 years with a low baseline PSA level (ie, <2.00 ng/mL) and possibly discontinued among those with baseline PSA levels of less than 1.00 ng/mL.

The Genomic and Molecular Pathology of Prostate Cancer: Clinical Implications for Diagnosis, Prognosis, and Therapy

Prostate cancer (PCa) is the most common noncutaneous malignancy affecting American men and the second most common cause of cancer death. The traditional risk classification schemes for PCa are limited due to the vast clinical and molecular heterogeneity of the disease. Fortunately, recent advancements in sequencing technologies have provided us with valuable insight into the genomics of PCa. To date, a wide array of recurrent genomic alterations in PCa have been identified. Incorporating these distinct molecular subtypes of PCa into prediction models provides opportunities for improved risk stratification and ultimately better patient outcomes. In this review, we summarize the key molecular subtypes of PCa and focus on those genomic alterations that have clinical implications for diagnosis, prognosis, and therapeutic response.

Impact of peri-prostatic fat measurements using MRI on the prediction of prostate cancer with transrectal ultrasound-guided biopsy

OBJECTIVES

To estimate the impact of peri-prostatic fat (PPF) measurements using preoperative magnetic resonance imaging on the prediction of prostate cancer (PCa) with transrectal ultrasound-guided biopsy.

PATIENTS AND METHODS

We performed a retrospective 2-center study on 660 consecutive patients receiving transrectal ultrasound-guided biopsy-biopsy from June 2016 to October 2018. Pathologic and immunohistochemical characteristics were collected. PPF measurements including PPF area (PPFA) and PPFA to prostate area (PA) ratio (PPFA/PA) were assessed by preoperative staging magnetic resonance imaging. Clinical variables were correlated with Gleason score by using Spearman (ρ) correlation coefficients. Multivariable analysis was performed to identify independent predictors of PCa. The diagnostic performance was estimated using ROC curves.

RESULTS

The Gleason score was significantly correlated with age (ρ = 0.114, P = 0.035), prostate-specific antigen (PSA) (ρ = 0.482, P < 0.001), PIRADS scoring (ρ = 0.403, P < 0.001) and PPFA/PA (ρ = 0.238, P < 0.001). Multivariate analysis revealed that PPFA/PA, age, digital rectal examination, family history of PCa, PSA, and PIRADS scoring were independently predictive of PCa. The ROC AUC to detect PCa or clinically significant PCa (CS-PCa; Gleason Score 3 + 4 or greater) improved with the addition of PPFA/PA (PCa: 0.93 vs. 0.89; CS-PCa: 0.92 vs. 0.90).

CONCLUSION

PPFA/PA is an independent predictor for PCa along with age, digital rectal examination, family history of PCa, PSA, and PIRADS scoring. PPF measurements especially PPFA/PA may help detect PCa or CS-PCa, thus helping improve PCa risk stratification and screening to avoid unnecessary biopsies.

Performance of the 4Kscore Test in Plasma and Serum and Stability of the Component Analytes in Clinical Samples

BACKGROUND

The 4Kscore Test determines a personalized risk score for aggressive prostate cancer by combining the blood sample measurements of total prostate-specific antigen (tPSA), free PSA (fPSA), intact PSA (iPSA), and human kallikrein-related peptidase 2 (hK2) with patient clinical information to generate the patient risk's score; thus, accuracy and precision of the 4Kscore depend on the reliability of these measurements. Although tPSA and fPSA are measured on a Food and Drug Administration (FDA)-approved platform, the performance of the iPSA and hK2 assays in the clinical setting has not previously been reported.

METHODS

Analytical performance was determined for the iPSA and hK2 assays in both serum and EDTA plasma, according to Clinical and Laboratory Standards Institute guidelines. Equivalence of the 4Kscore in both sample matrices was demonstrated in a 353-patient clinical cohort, and the stability of endogenous iPSA and hK2 for at least 3 days was demonstrated in a smaller subset.

RESULTS

Intralaboratory and interlaboratory precision of the iPSA and hK2 assays in both matrices was comparable with that of FDA-approved tPSA and fPSA assays (<18% for iPSA; <8% for hK2). The picogram per milliliter sensitivity and wide dynamic range of the iPSA and hK2 assays allowed for accurate measurements in the target population. The 4Kscore generated in either matrix up to 3 days after collection is equivalent to that measured within 24 h of collection (Passing-Bablok slope 95% CI: plasma, 0.999-1.034; serum, 0.997-1.040).

CONCLUSIONS

The robust performance of component assays and reliable stability of the endogenous analytes in clinical samples proven here ensures an accurate 4Kscore Test result.

LacdiNAc-Glycosylated Prostate-specific Antigen Density is a Potential Biomarker of Prostate Cancer

BACKGROUND

Serum LacdiNAc-glycosylated prostate-specific antigen (LDN-PSA) and LDN-PSA density together with PSA and PSA density (PSAD) were measured as a diagnostic tool for prostate cancer (PCa).

PATIENTS AND METHODS

We included 150 patients with PCa without hormonal therapy and 41 patients without PCa obtained from the Kyoto University Hospital between 2012 and 2017. LDN-PSA levels were measured through a WFA-anti-PSA antibody sandwich immunoassay using a highly sensitive surface plasmon field-enhanced fluorescence spectroscopy (SPFS) system. Diagnostic performance of serum LDN-PSA and LDN-PSAD was evaluated by measuring the area under the receiver-operating characteristic curve (AUC).

RESULTS

The AUCs of LDN-PSA, LDN-PSAD, and PSAD levels (0.780, 0.848, and 0.835, respectively) detected in patients with PCa were significantly higher (P = .0001, P < .0001, and P < .0001, respectively) than that of PSA (0.590). Moreover, among 143 patients with PCa who received radical prostatectomy (RP), the AUCs of LDN-PSA, LDN-PSAD, and PSAD levels (0.750, 0.812, and 0.769, respectively) detected in patients with a pathologic Gleason grade group ≥ 2 were significantly higher (P = .0170, P = .0028, and P = .0003, respectively) than that of PSA (0.578). In the group comprising 35 patients who received RP with a Gleason grade group 1-graded biopsy, the LDN-PSA, LDN-PSAD, and PSAD levels were significantly different (P = .0097, P = .0024, and P = .0312, respectively). However, PSA alone could not discriminate cases with adverse features (P = .454).

CONCLUSIONS

LDN-PSAD is a potential marker for detecting PCa and selecting candidates for RP.

Developing an effective strategy to improve the detection of significant prostate cancer by combining the 4Kscore and multiparametric MRI

OBJECTIVES

Recent years have seen the development of biomarkers and imaging technologies designed to improve the specificity of PSA. Widespread implementation of imaging technologies, such as mp-MRI raises considerable logistical challenges. Our objective was to evaluate a biopsy strategy that utilizes selective mp-MRI as a follow-up test to biomarkers to improve the detection of significant prostate cancer.

METHODS AND MATERIALS

We developed a conceptual approach based on the risk calculated from the 4Kscore using results from the US prospective validation study, multiplied by the likelihood ratio of mp-MRI from the PROMIS trial. The primary outcome was Gleason grade ≥ 7 (grade group ≥ 2) cancer on biopsy. Using decision curve analysis, the net benefit was determined for our model and compared with the use of the 4Kscore and mp-MRI independently at various thresholds for biopsy.

RESULTS

For a cut-point of 7.5% risk of high-grade disease, patients with <5% risk from a blood marker would not have risk of significant prostate cancer sufficiently increased by a positive mp-MRI to warrant biopsy; comparably, patients with a risk >23% would not have risk sufficiently reduced by a negative imaging study to forgo biopsy. From the 4Kscore validation study, 46% of men considered for biopsy in the US have risks 5% to 23%. Net benefit was highest for the combined strategy, followed by 4Kscore alone.

CONCLUSIONS

Selective mp-MRI in men with intermediate scores on a secondary blood test results in a biopsy strategy that is more scalable than mp-MRI for all men with elevated PSA. Prospective validation is required to demonstrate if the predicted properties of combined blood and imaging testing are empirically confirmed.

Avoiding Unnecessary Magnetic Resonance Imaging (MRI) and Biopsies: Negative and Positive Predictive Value of MRI According to Prostate-specific Antigen Density, 4Kscore and Risk Calculators

The 2019 European Association of Urology guidelines recommend multiparametric magnetic resonance imaging (mpMRI) for biopsy-naïve patients with clinical suspicion of prostate cancer (PC) and avoiding biopsy in patients with negative mpMRI and low clinical suspicion. However, consensus on the optimal definition of low clinical suspicion is lacking. We evaluated 266 biopsy-naïve patients who underwent mpMRI, the 4Kscore test, and prostate biopsy to define the best strategy to avoid unnecessary testing and biopsies. The European Randomized Study of Screening for Prostate Cancer risk calculator (ERSPC-RC) and prostate-specific antigen density (PSAd) were also considered. For men with Prostate Imaging-Reporting and Data System v2.0 (PI-RADS) 1⿿2 lesions, the highest negative predictive value was observed for those with low or intermediate 4Kscore risk (96.9% and 97.1%), PSAd <0.10ng/ml/cm³ (98.7%), and ERSPC-RC <2% (98.7%). For men with PI-RADS 3⿿5 lesions the lowest positive predictive value was observed for those with low 4Kscore risk (0%), PSAd <0.10ng/ml/cm³ (13.2%), and ERSPC-RC <2% (12.3%). The best biopsy strategy was an initial 4Kscore followed by mpMRI if the 4Kscore was>7.5% and a subsequent biopsy if the mpMRI was positive (PI-RADS 3⿿5) or the 4Kscore was ⿥18%. This would result in missing 2.7% (2/74) of clinically significant PCs (csPCs) and avoiding 34.2% of biopsies. Initial mpMRI followed by biopsy for negative mpMRI (PI-RADS 1⿿2) if the 4Kscore was ⿥18% or PSAd was ⿥0.10ng/ml/cm³ resulted in a similar percentage of csPC missed (2.7% [2/74] and 1.3% [1/74]) but slightly fewer biopsies avoided (25.2% and 28.1%). Physicians should consider clinical risk screening tools when ordering and interpreting mpMRI results to avoid unnecessary testing and diagnostic errors. PATIENT SUMMARY: Performing the 4Kscore test in conjunction with multiparametric magnetic resonance imaging for men with a clinical suspicion of prostate cancer may help to reduce unnecessary biopsies.

Performance of PCA3 and TMPRSS2:ERG urinary biomarkers in prediction of biopsy outcome in the Canary Prostate Active Surveillance Study (PASS)

BACKGROUND

For men on active surveillance for prostate cancer, biomarkers may improve prediction of reclassification to higher grade or volume cancer. This study examined the association of urinary PCA3 and TMPRSS2:ERG (T2:ERG) with biopsy-based reclassification.

METHODS

Urine was collected at baseline, 6, 12, and 24 months in the multi-institutional Canary Prostate Active Surveillance Study (PASS), and PCA3 and T2:ERG levels were quantitated. Reclassification was an increase in Gleason score or ratio of biopsy cores with cancer to ≥34%. The association of biomarker scores, adjusted for common clinical variables, with short- and long-term reclassification was evaluated. Discriminatory capacity of models with clinical variables alone or with biomarkers was assessed using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

Seven hundred and eighty-two men contributed 2069 urine specimens. After adjusting for PSA, prostate size, and ratio of biopsy cores with cancer, PCA3 but not T2:ERG was associated with short-term reclassification at the first surveillance biopsy (OR = 1.3; 95% CI 1.0-1.7, p = 0.02). The addition of PCA3 to a model with clinical variables improved area under the curve from 0.743 to 0.753 and increased net benefit minimally. After adjusting for clinical variables, neither marker nor marker kinetics was associated with time to reclassification in subsequent biopsies.

CONCLUSIONS

PCA3 but not T2:ERG was associated with cancer reclassification in the first surveillance biopsy but has negligible improvement over clinical variables alone in ROC or DCA analyses. Neither marker was associated with reclassification in subsequent biopsies.

Application of Urinary Volatile Organic Compounds (VOCs) for the Diagnosis of Prostate Cancer

BACKGROUND

Prostate cancer (PCa) screening using serum prostate-specific antigen (PSA) testing has caused unnecessary biopsies and overdiagnosis owing to its low accuracy and reliability. Therefore, there is an increased interest in identifying better PCa biomarkers. Studies showed that trained dogs can discriminate patients with PCa from unaffected men by sniffing urine. We hypothesized that urinary volatile organic compounds (VOCs) may be the source of that odor and could be used to develop urinary VOC PCa diagnosis models.

PATIENTS AND METHODS

Urine samples from 55 and 53 biopsy proven PCa-positive and -negative patients respectively were initially obtained for diagnostic model development. Urinary metabolites were analyzed by gas chromatography-mass spectrometry. A PCa diagnosis model was developed and validated using innovative statistical machine-learning techniques. A second set of samples (53 PCa-positive and 22 PCa-negative patients) were used to evaluate the previously developed PCa diagnosis model.

RESULTS

The analysis resulted in 254 and 282 VOCs for their significant association (P < .05) with either PCa-positive or -negative samples respectively. Regularized logistic regression analysis and the Firth method were then applied to predict PCa prevalence, resulting in a final model that contains 11 VOCs. Under cross-validation, the area under the receiver operating characteristic curve (AUC) for the final model was 0.92 (sensitivity, 0.96; specificity, 0.80). Further evaluation of the developed model using a testing cohort yielded an AUC of 0.86. As a comparison, the PSA-based diagnosis model only rendered an AUC of 0.54.

CONCLUSION

The study describes the development of a urinary VOC-based model for PCa detection.

The State of the Science on Prostate Cancer Biomarkers: The San Francisco Consensus Statement

We convened a multidisciplinary expert panel to make recommendations on current utility and future research needs for post-diagnosis prostate cancer biomarkers. The San Francisco Consensus Statement reflects on the rapid recent progress achieved, and the substantial work still ahead.

The miRNA-kallikrein interaction: a mosaic of epigenetic regulation in cancer

The kallikrein-related peptidases (KLKs) constitute a family of 15 highly conserved serine proteases with trypsin- and chymotrypsin-like activities. Dysregulated expression and/or aberrant activation of KLKs has been linked to various pathophysiological processes, including cancer. Many KLKs have been identified as potential cancer biomarkers. microRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression by pairing to the 3' untranslated region (UTR) of complimentary mRNA targets. miRNAs are dysregulated in many cancers, including prostate, kidney and ovarian cancers. Several studies have shown that miRNAs are involved in the post-transcriptional regulation of KLKs. However, recent evidence suggests that miRNAs can also act as downstream effectors of KLKs. In this review, we provide an update on the epigenetic regulation of KLKs by miRNAs. We also present recent experimental evidence that supports the regulatory role of KLKs on miRNA networks. The potential diagnostic and therapeutic applications of miRNA-kallikrein interactions are also discussed.

MiR-30a-5p frequently downregulated in prostate cancer inhibits cell proliferation via targeting PCLAF

MicroRNAs (miRNAs) have vastly expanded our view of RNA world in intracellular signal regulating networks. Here, we functionally characterized a normally highly expressed miRNA, miR-30a-5p (MIMAT0000087), which exhibits downregulated expression profiles in prostate cancer samples. MiR-30a-5p knockdown and overexpression in PC-3 cell line alters cell proliferation supporting a tumour suppressor role. We also discovered that PCLAF is the direct target of miR-30a-5p. Notably, PC-3 cell proliferation is inhibited by miR-30a-5p/PCLAF axis. miR-30a-5p represents a novel molecule of functionally important miRNAs which may shed light on the novel therapeutic targets for prostate cancer.

A critical appraisal of biomarkers in prostate cancer

PURPOSE

A number of urine and blood-based biomarker tests have been described for prostate cancer, although to date there has only been a limited exploration of the methodology behind the validation studies that underpin these tests.

METHODS

In this review, a selection of commercially available urine and blood-based biomarker tests for prostate cancer are described, and the underlying key validation studies for each test are critically appraised using the Standards for Reporting Diagnostic Accuracy (STARD) 2015 statement.

RESULTS

The ExoDx Prostate Intelliscore, SelectMDx, Progensa PCA3, Mi-Prostate Score, 4K Score, and Prostate Health Index (PHI) tests were reviewed. Most of the validation studies supporting these tests perform exploratory analyses to determine cut-off values in a post hoc manner, comprise cohorts that are primarily Caucasian, report receiver operating characteristic curves that combine the biomarker's result with established clinical nomograms and are based on a reference standard (prostate biopsy) that lacks central pathology review. Deficiencies in STARD reporting guidelines include frequent failure to provide a published study protocol, prospective study registration in a registry, a flow diagram, justification for sample size determination, a discussion of adverse events with testing, and information on how missing or indeterminate test results should be managed.

CONCLUSIONS

Key validation studies that support many commercially available urine and blood-based biomarkers for prostate cancers have deficiencies in transparency based on STARD reporting guidelines, and limitations in methodology must be considered when deciding when these tests should be applied in clinical practice.

Changes in risk-group stratification of patients undergoing radical prostatectomy at the Southern Alberta Institute of Urology over time

Introduction

Prostate cancer is the most common cancer among men, but overall mortality rates remain low, due to the preponderance of low-risk disease. Over the last decade, there has been a shift toward more conservative management in low-risk prostate cancer, in order to minimize unnecessary intervention. This study aimed to evaluate the number of low-risk radical prostatectomies (RPs) being performed at the Southern Alberta Institute of Urology over a 10-year period.

Methods

We retrospectively reviewed all patients who underwent RP from 2005 to 2014 at our institution. Patients were stratified by D’Amico risk classification and grade group based on 12-core transrectal ultrasound–guided biopsy (TRUS-bx) results. RP findings are reported from February 2005 to October 2014 to describe concordance between TRUS-bx and RPs. Basic descriptive analyses were used for this study.

Results

Over the study period, 2,310 RPs were performed in our institution. Overall, 35.2% of these were performed on men with low-risk prostate cancer. From 2005 to 2014, the proportion of RPs performed for low-risk prostate cancer dropped from 54.0% to 8.9%, and 49.8% of patients who underwent RP for low-risk disease experienced pathologic upgrading, though only 3.8% were upgraded to grade group 3 or greater. Other adverse pathological findings were uniformly low among the low-risk group.

Conclusion

The proportion of patients undergoing RP at our center for low-risk prostate cancer decreased significantly over the 10 years evaluated in this study, reflecting current global trends toward active surveillance in the management of low-risk prostate cancer.

Prediction Medicine: Biomarkers, Risk Calculators and Magnetic Resonance Imaging as Risk Stratification Tools in Prostate Cancer Diagnosis

This review discusses the most recent evidence for currently available risk stratification tools in the detection of clinically significant prostate cancer (csPCa), and evaluates diagnostic strategies that combine these tools. Novel blood biomarkers, such as the Prostate Health Index (PHI) and 4Kscore, show similar ability to predict csPCa. Prostate cancer antigen 3 (PCA3) is a urinary biomarker that has inferior prediction of csPCa compared to PHI, but may be combined with other markers like TMPRSS2-ERG to improve its performance. Original risk calculators (RCs) have the advantage of incorporating easy to retrieve clinical variables and being freely accessible as a web tool/mobile application. RCs perform similarly well as most novel biomarkers. New promising risk models including novel (genetic) markers are the SelectMDx and Stockholm-3 model (S3M). Prostate magnetic resonance imaging (MRI) has evolved as an appealing tool in the diagnostic arsenal with even stratifying abilities, including in the initial biopsy setting. Merging biomarkers, RCs and MRI results in higher performances than their use as standalone tests. In the current era of prostate MRI, the way forward seems to be multivariable risk assessment based on blood and clinical parameters, potentially extended with information from urine samples, as a triaging test for the selection of candidates for MRI and biopsy.

Diagnosis of prostate cancer

Diagnosis of prostate cancer (PCa) and adequate staging play a fundamental role for clinical and patient care. Despite major advances in biology and imaging, rectal examination and prostate-specific antigen (PSA) blood test remain the cornerstone for screening, and multiparametricmagnetic resonance imaging (mpMRI) for local staging. Recent advances in mpMRI lead to standardised interpretation and increased prescription by clinicians in order to improve detection of clinically significant PCa and select patients requiring targeted biopsies. However its indication remains controversial in biopsy-naïve patients. Nuclear medicine is also in a continuous evolution and utilisation of new radiopharmaceutical agent like choline or 68gallium with computed tomography or magnetic resonance imaging has led to the improvement in the detection of lymph nodes, distant metastases and prostate recurrence. Considering this very heterogneneous disease, combined utilisation of these tools will help clinicians and patients in choosing the most appropriate and personalised treatment.

Obstacles in prostate cancer screening: Current issues and future solutions

Prostate cancer is the most common cancer in men and is associated with unacceptably high mortality rates, yet an accurate and acceptable screening programme that detects clinically significant prostate cancer remains elusive. Although there is good evidence that prostate-specific antigen (PSA)-based screening lowers prostate cancer-specific mortality, especially when conducted at high intensity, the harm caused by overinvestigation, overdiagnosis and overtreatment of clinically insignificant cases arguably outweighs these benefits. Several attempts have therefore been made to improve screening, enhancing the diagnostic value of PSA and identifying novel modalities for screening. Here, we provide a comprehensive review of the benefits and harms, and analyse which of these novel screening methods show most promise.

Level of evidence: 5, expert opinion

Circulating blood miRNAs for prostate cancer risk stratification: miRroring the underlying tumor biology with liquid biopsies

Current risk stratification methods for prostate cancer – although they have seen marked improvements over the past decades – are far from perfect. Despite the significant utility of prostate-specific antigen as a biomarker to monitor for disease recurrence, it cannot predict which tumors will recur or recommend the best treatment for patients. Similarly, although biopsies are imperative for diagnosis and staging, they are saddled with limitations and risks. We must move toward a noninvasive biomarker that has predictive and prognostic efficacy. We therefore review the current literature on circulating miRNA biomarkers, apply their use to two significant clinical problems (ie, how limitations of prostate biopsies can impact diagnosis and treatment management, and the need to tailor treatment for a clinically heterogeneous disease), and evaluate how circulating miRNAs have inherent properties that make them ideal liquid biomarkers. We also outline current gaps in knowledge that must be addressed before they can be implemented into routine clinical practice. With further research on their function and validation of their biomarker utility in large prospective cohorts, circulating miRNAs will likely prove to be the liquid biopsies of tomorrow.

Combining urinary DNA methylation and cell-free microRNA biomarkers for improved monitoring of prostate cancer patients on active surveillance

PURPOSE

Prostate cancer (CaP) patients with low-grade tumors are enrolled in active surveillance (AS) programs and monitored with digital rectal exams (DREs), prostate-specific antigen (PSA) tests, and periodic invasive biopsies. Patients are "reclassified" with higher-risk disease if they show signs of disease progression. However, AS patients who will reclassify cannot be easily identified upfront and suffer morbidities associated with biopsy. Biomarkers derived from noninvasively obtained specimens such as serum or urine samples are promising alternatives to monitor patients with clinically insignificant cancer. Previously, we have characterized and validated a urinary DNA methylation panel and a serum miRNA panel for the prediction of patient reclassification in 2 independent AS cohorts. In this exploratory study, we have investigated cell-free miRNAs in the urinary supernatant combined with urinary DNA methylation markers to form an integrative panel for prediction of AS patient reclassification.

METHODS

Post-DRE urine was collected from 103 CaP patients on active surveillance. Urinary sediment DNA methylation levels of selected genes were previously analyzed using qPCR-based MethyLight assay. Using qRT-PCR, we analyzed the urinary supernatants for relative quantities of 10 miRNAs previously shown to be associated with AS reclassification. Logistic regression and Receiver Operating Characteristics curve analyses were performed to assess the predictive ability of miRNAs and DNA methylation biomarkers.

RESULTS

We identified a 3-marker panel, consisting of miR-24, miR-30c and CRIP3 methylation, that was significant for prediction of patient reclassification (Odds ratio = 2.166, 95% confidence interval = 1.22-3.847) with a negative predictive value of 90.9%. Our 3-marker panel also demonstrated additive value to PSA for prediction of patient reclassification (c-statistic = 0.717, ROC bootstrapped 1000 iteration P = 0.041).

CONCLUSION

A urinary integrated panel of methylation and miRNA markers is a promising approach to identify AS patients at risk for reclassification. Our 3-marker panel, with its high negative predictive value, would be beneficial to identify and preclude AS patients with truly indolent cancer and to personalize monitoring strategies for AS patients.

Modern urology perspectives on prostate cancer biomarkers

Introduction

Prostate cancer (PCa) is the most common type of cancer among men in Europe. Current recommendations for screening and diagnosis are based on prostate-specific antigen (PSA) measurements and the digital rectal examination (DRE). Both of them are triggers for prostate biopsy. Limited specificity of the PSA test brings, however, a need to develop new, better diagnostic tools. Several commercially available variations of the PSA test including: prostate health index (PHI), 4Kscore as well as molecular PCA3 score, have already revealed its value, lowering the number of unnecessary biopsies.

Material and methods

This review summarizes published results of the current most promising, clinically proven and experimentally evaluated PCa biomarkers which have potential for creation of new diagnostic tests.

Results

In the last few years new approaches for providing significantly better biomarkers, an alternative to PSA, have been introduced. Modern biomarkers show improvement in being used as not only a diagnosis procedure, but also for staging, evaluating aggressiveness and managing the therapeutic process. The most promising group are molecular markers, among them microRNAs(miRNAs) and long noncoding RNAs (lncRNAs) are most frequent. Their superiority, over standard PSA, in predicting tumor formation in early stages, and clinically non-symptomatic metastases has been noticed. Extracellular vesicles presence in biofluids have brought focus of many research groups, indicating their potential significance. This group of nanoparticles has potential not only in diagnostic and therapy management process, but also as a potential therapeutic target.

Conclusions

Finding better PCa biomarkers, replacing the current PSA measurement, is firmly needed in modern urology practice.