Pathological Outcomes of Candidates for Active Surveillance of Prostate Cancer

An 18-gene signature of recurrence-associated endothelial cells predicts tumor progression and castration resistance in prostate cancer

BACKGROUND

The prognostic and therapeutic implications of endothelial cells (ECs) heterogeneity in prostate cancer (PCa) are poorly understood.

METHODS

We investigated associations of EC heterogeneity with PCa recurrence and castration resistance in 8 bulk transcriptomic and 4 single-cell RNA-seq cohorts. A recurrence-associated EC (RAEC) signature was constructed by comparing 11 machine learning algorithms through nested cross-validation. Functional relevances of RAEC-specific genes were also tested.

RESULTS

A subset of ECs was significantly associated with recurrence in primary PCa and named RAECs. RAECs were characteristic of tip and immature cells and were enriched in migration, angiogenesis, and collagen-related pathways. We then developed an 18-gene RAEC signature (RAECsig) representative of RAECs. Higher RAECsig scores independently predicted tumor recurrence and performed better or comparably compared to clinicopathological factors and commercial gene signatures in multiple PCa cohorts. Of the 18 RAECsig genes, FSCN1 was upregulated in ECs from PCa with higher Gleason scores; and the silencing of FSCN1, TMEME255B, or GABRD in ECs either attenuated tube formation or inhibited PCa cell proliferation. Finally, higher RAECsig scores predicted castration resistance in both primary and castration-resistant PCa.

CONCLUSION

This study establishes an endothelial signature that links a subset of ECs to prostate cancer recurrence and castration resistance.

[68Ga]Ga‑PSMA‑617 PET-based radiomics model to identify candidates for active surveillance amongst patients with GGG 1-2 prostate cancer at biopsy

PURPOSE

To develop a radiomics-based model using [68Ga]Ga-PSMA PET/CT to predict postoperative adverse pathology (AP) in patients with biopsy Gleason Grade Group (GGG) 1-2 prostate cancer (PCa), assisting in the selection of patients for active surveillance (AS).

METHODS

A total of 75 men with biopsy GGG 1-2 PCa who underwent radical prostatectomy (RP) were enrolled. The patients were randomly divided into a training group (70%) and a testing group (30%). Radiomics features of entire prostate were extracted from the [68Ga]Ga-PSMA PET scans and selected using the minimum redundancy maximum relevance algorithm and the least absolute shrinkage and selection operator regression model. Logistic regression analyses were conducted to construct the prediction models. Receiver operating characteristic (ROC) curve, decision curve analysis (DCA), and calibration curve were employed to evaluate the diagnostic value, clinical utility, and predictive accuracy of the models, respectively.

RESULTS

Among the 75 patients, 30 had AP confirmed by RP. The clinical model showed an area under the curve (AUC) of 0.821 (0.695-0.947) in the training set and 0.795 (0.603-0.987) in the testing set. The radiomics model achieved AUC values of 0.830 (0.720-0.941) in the training set and 0.829 (0.624-1.000) in the testing set. The combined model, which incorporated the Radiomics score (Radscore) and free prostate-specific antigen (FPSA)/total prostate-specific antigen (TPSA), demonstrated higher diagnostic efficacy than both the clinical and radiomics models, with AUC values of 0.875 (0.780-0.970) in the training set and 0.872 (0.678-1.000) in the testing set. DCA showed that the net benefits of the combined model and radiomics model exceeded those of the clinical model.

CONCLUSION

The combined model shows potential in stratifying men with biopsy GGG 1-2 PCa based on the presence of AP at final pathology and outperforms models based solely on clinical or radiomics features. It may be expected to aid urologists in better selecting suitable patients for AS.

Pathology Data-Based Risk Group Stratification Is Equivalent to That Obtained by Oncotype DX Testing in Prostatic Adenocarcinoma

CONTEXT.—

Low-risk (Gleason score 3 + 3 = 6) and intermediate-risk (Gleason score 3 + 4 = 7) prostate carcinoma cases diagnosed on needle biopsies are frequently referred for gene expression studies such as Oncotype DX to help validate the risk. Risk assessment helps in determining prognosis and therapeutic decision making.

OBJECTIVE.—

To determine if addition of molecular testing is necessary, by evaluating its correlation with risk stratification provided by pathology report (Gleason score, Grade Group, proportion of positive cores) and serum prostate-specific antigen (PSA) level.

DESIGN.—

Our institutional database was searched for cases that had Oncotype DX testing after prostate biopsy. The final risk category determined by molecular testing was compared to the risk stratification predicted by the pathology report and serum PSA levels. Cases were classified as concordant if they fell under the same National Comprehensive Cancer Network risk and recommended initial therapy group. Follow-up information on discordant cases was obtained and used to determine if risk stratification by molecular testing was superior to that obtained from the clinicopathologic data.

RESULTS.—

A total of 4967 prostate biopsies (2015-2020) were screened. Of these, 131 prostate carcinoma cases (2.6%) had Oncotype DX testing and 111 of 131 cases (85%) had follow-up information. There was risk stratification concordance in 93 of 111 cases (84%). All 18 of 111 cases (16%) that were discordant had a follow-up course that matched the risk predicted by pathology data and serum PSA.

CONCLUSIONS.—

Risk stratification provided by information in the pathology report on routine biopsy assessment coupled with the serum PSA level is equivalent to that obtained by Oncotype DX testing.

Modern Active Surveillance in Prostate Cancer: A Narrative Review

The use of PSA screening has led to downstaging and downgrading of prostate cancer at diagnosis, increasing detection of indolent disease. Active surveillance aims to reduce over-treatment by delaying or avoiding radical treatment and its associated morbidity. However, there is not a consensus on the selection criteria and monitoring schedules that should be used. This article aims to summarize the evidence supporting the safety of active surveillance, the current selection criteria recommended and in use, the incidence of active surveillance, barriers existing to its uptake and future developments in patient selection.

A machine learning framework develops a DNA replication stress model for predicting clinical outcomes and therapeutic vulnerability in primary prostate cancer

Recent studies have identified DNA replication stress as an important feature of advanced prostate cancer (PCa). The identification of biomarkers for DNA replication stress could therefore facilitate risk stratification and help inform treatment options for PCa. Here, we designed a robust machine learning-based framework to comprehensively explore the impact of DNA replication stress on prognosis and treatment in 5 PCa bulk transcriptomic cohorts with a total of 905 patients. Bootstrap resampling-based univariate Cox regression and Boruta algorithm were applied to select a subset of DNA replication stress genes that were more clinically relevant. Next, we benchmarked 7 survival-related machine-learning algorithms for PCa recurrence using nested cross-validation. Multi-omic and drug sensitivity data were also utilized to characterize PCa with various DNA replication stress. We found that the hyperparameter-tuned eXtreme Gradient Boosting model outperformed other tuned models and was therefore used to establish a robust replication stress signature (RSS). RSS demonstrated superior performance over most clinical features and other PCa signatures in predicting PCa recurrence across cohorts. Lower RSS was characterized by enriched metabolism pathways, high androgen activity, and a favorable prognosis. In contrast, higher RSS was significantly associated with TP53, RB1, and PTEN deletion, exhibited increased proliferation and DNA replication stress, and was more immune-suppressive with a higher chance of immunotherapy response. In silico screening identified 13 potential targets (e.g. TOP2A, CDK9, and RRM2) from 2249 druggable targets, and 2 therapeutic agents (irinotecan and topotecan) for RSS-high patients. Additionally, RSS-high patients were more responsive to taxane-based chemotherapy and Poly (ADP-ribose) polymerase inhibitors, whereas RSS-low patients were more sensitive to androgen deprivation therapy. In conclusion, a robust machine-learning framework was used to reveal the great potential of RSS for personalized risk stratification and therapeutic implications in PCa.

Hidden clues in prostate cancer - Lessons learned from clinical and pre-clinical approaches on diagnosis and risk stratification

The heterogeneity of prostate cancer is evident at clinical, morphological and molecular levels. To aid clinical decision making, a three-tiered system for risk stratification is used to designate low-, intermediate-, and high-risk of disease progression. Intermediate-risk prostate cancers are the most frequently diagnosed, and even with common diagnostic features, can exhibit vastly different clinical progression. Thus, improved risk stratification methods are needed to better predict patient outcomes. Here, we provide an overview of the improvements in diagnosis/prognosis arising from advances in pathology reporting of prostate cancer, which can improve risk stratification, especially for patients with intermediate-risk disease. This review discusses updates to pathology reporting of morphological growth patterns, and proposes the utility of integrating prognostic biomarkers or innovative imaging techniques to enhance clinical decision-making. To complement clinical studies, experimental approaches using patient-derived tumors have highlighted important cellular and morphological features associated with aggressive disease that may impact treatment response. The intersection of urology, pathology and scientific disciplines is required to work towards a common goal of understanding disease pathogenesis, improving the stratification of patients with intermediate-risk disease and subsequently defining optimal treatment strategies using precision-based approaches.

MicroRNA-regulated transcriptome analysis identifies four major subtypes with prognostic and therapeutic implications in prostate cancer

MicroRNA (miRNA) deregulation plays a critical role in the heterogeneous development of prostate cancer (PCa) by tuning mRNA levels. Herein, we aimed to characterize the molecular features of PCa by clustering the miRNA-regulated transcriptome with non-negative matrix factorization. Using 478 PCa samples from The Cancer Genome Atlas, four molecular subtypes (S-I, S-II, S-III, and S-IV) were identified and validated in two merged microarray and RNAseq datasets with 656 and 252 samples, respectively. Interestingly, the four subtypes showed distinct clinical and biological features after comprehensive analyses of clinical features, multiomic profiles, immune infiltration, and drug sensitivity. S-I is basal/stem/mesenchymal-like and immune-excluded with marked transforming growth factor β, epithelial-mesenchymal transition and hypoxia signals, increased sensitivity to olaparib, and intermediate prognosis. S-II is luminal/metabolism-active and responsive to androgen deprivation therapy with frequent TMPRSS2-ERG fusion and a good prognosis. S-III is characterized by moderate proliferative and metabolic activity, sensitivity to taxane-based chemotherapy, and intermediate prognosis. S-IV is highly proliferative with moderate EMT and stemness, frequent deletions of TP53, PTEN and RB, and the poorest prognosis; it is also immune-inflamed and sensitive to anti-PD-L1 therapy. Overall, based on miRNA-regulated gene profiles, this study identified four distinct PCa subtypes that could improve risk stratification at diagnosis and provide therapeutic guidance.

Advances in the selection of patients with prostate cancer for active surveillance

Early identification and management of prostate cancer completely changed with the discovery of prostate-specific antigen. However, improved detection has also led to overdiagnosis and consequently overtreatment of patients with low-risk disease. Strategies for the management of patients using active surveillance - the monitoring of clinically insignificant disease until intervention is warranted - were developed in response to this issue. The success of this approach is critically dependent on the accurate selection of patients who are predicted to be at the lowest risk of prostate cancer mortality. The Epstein criteria for clinically insignificant prostate cancer were first published in 1994 and have been repeatedly validated for risk-stratification and selection for active surveillance over the past few decades. Current active surveillance programmes use modified criteria with 30-50% of patients receiving treatment at 10 years. Nonetheless, tools for prostate cancer diagnosis have continued to evolve with improvements in biopsy format and targeting, advances in imaging technologies such as multiparametric MRI, and the identification of serum-, tissue- and urine-based biomarkers. These advances have the potential to further improve the identification of men with low-risk disease who can be appropriately managed using active surveillance.

A novel nomogram to identify candidates for active surveillance amongst patients with International Society of Urological Pathology (ISUP) Grade Group (GG) 1 or ISUP GG2 prostate cancer, according to multiparametric magnetic resonance imaging findings

OBJECTIVES

To develop a novel nomogram to identify candidates for active surveillance (AS) that combines clinical, biopsy and multiparametric magnetic resonance imaging (mpMRI) findings; and to compare its predictive accuracy to, respectively: (i) Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, (ii) Johns Hopkins (JH) criteria, (iii) European Association of Urology (EAU) low-risk classification, and (iv) EAU low-risk or low-volume with International Society of Urological Pathology (ISUP) Grade Group (GG) 2 classification.

PATIENTS AND METHODS

We selected 1837 patients with ISUP GG1 or GG2 prostate cancer (PCa), treated with radical prostatectomy (RP) between 2012 and 2018. The outcome of interest was the presence of unfavourable disease (i.e., clinically significant PCa [csPCa]) at RP, defined as: ISUP GG ≥ 3 and/or pathological T stage (pT) ≥3a and/or pathological N stage (pN) 1. First, logistic regression models including PRIAS, JH, EAU low-risk, and EAU low-risk or low-volume ISUP GG2 binary classifications (not eligible vs eligible) were used. Second, a multivariable logistic regression model including age, prostate-specific antigen density (PSA-D), ISUP GG, and the percentage of positive cores (Model 1) was fitted. Third, Prostate Imaging-Reporting and Data System (PI-RADS) score (Model 2), extracapsular extension (ECE) score (Model 3) and PI-RADS + ECE score (Model 4) were added to Model 1. Only variables associated with higher csPCa rates in Model 4 were retained in the final simplified Model 5. The area under the receiver operating characteristic curve (AUC), calibration plots and decision curve analyses were used.

RESULTS

Of the 1837 patients, 775 (42.2%) had csPCa at RP. Overall, 837 (47.5%), 986 (53.7%), 348 (18.9%), and 209 (11.4%) patients were eligible for AS according to, respectively, the EAU low-risk, EAU low-risk or low-volume ISUP GG2, PRIAS, and JH criteria. The proportion of csPCa amongst the EAU low-risk, EAU low-risk or low-volume ISUP GG2, PRIAS and JH candidates was, respectively 28.5%, 29.3%, 25.6% and 17.2%. Model 4 and Model 5 (in which only PSA-D, ISUP GG, PI-RADS and ECE score were retained) had a greater AUC (0.84), compared to the four proposed AS criteria (all P < 0.001). The adoption of a 25% nomogram threshold increased the proportion of AS-eligible patients from 18.9% (PRIAS) and 11.4% (JH) to 44.4%. Moreover, the same 25% nomogram threshold resulted in significantly lower estimated risks of csPCa (11.3%), compared to PRIAS (Δ: -14.3%), JH (Δ: -5.9%), EAU low-risk (Δ: -17.2%), and EAU low-risk or low-volume ISUP GG2 classifications (Δ: -18.0%).

CONCLUSION

The novel nomogram combining clinical, biopsy and mpMRI findings was able to increase by ~25% and 35% the absolute frequency of patients suitable for AS, compared to, respectively, the PRIAS or JH criteria. Moreover, this nomogram significantly reduced the estimated frequency of csPCa that would be recommended for AS compared to, respectively, the PRIAS, JH, EAU low-risk, and EAU low-risk or low-volume ISUP GG2 classifications.

Confirmatory multiparametric magnetic resonance imaging at recruitment confers prolonged stay in active surveillance and decreases the rate of upgrading at follow-up

BACKGROUND

To understand the value of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsies at recruitment on active surveillance (AS) outcomes.

MATERIALS AND METHODS

This retrospective single-center study enrolled two cohorts of 206 and 310 patients in AS. The latter group was submitted to mpMRI and targeted biopsies at recruitment. Kaplan-meier curves quantified progression-free survival (PFS) and Bioptic-PFS (B-PFS: no upgrading or >3 positive cores) in the two cohorts. Cox-regression analyses tested independent predictors of PFS and B-PFS. In patients submitted to radical prostatectomy (RP) after AS, significant cancer (csPCa) was defined as: GS ≥ 4 + 3 and/or pT ≥ 3a and/or pN+ . Logistic-regression analyses predicted csPCa at RP.

RESULTS AND LIMITATIONS

Median time follow-up and median time of persistence in AS were 46 (24-70) and 36 (23-58) months, respectively. Patients submitted to mpMRI at AS begin, showed greater PFS at 1- (98% vs. 91%), 3- (80% vs. 57%), and 5-years (70% vs. 35%) follow-up, respectively (all p < 0.01). At Cox-regression analysis only confirmatory mpMRI± targeted biopsy (HR: 0.3; 95% CI 0.2-0.5; p < 0.01) at AS begin was an independent predictor of PFS. Globally, 50 (16%) vs. 128 (62%) and 26 (8.5%) vs. 64 (31%) [all p < 0.01] men in the two groups experienced any-cause and bioptic AS discontinuation, respectively. Patients submitted to confirmatory mpMRI experienced greater 1-(98% vs. 93%), 3-(90% vs. 75%), and 5-years (83% vs. 56%) B-PFS, respectively (all p < 0.01). At Cox-regression analysis, mpMRI±-targeted biopsy at AS begin was associated with B-PFS (HR: 0.3; 95% CI 0.2-0.6; p < 0.01). No differences were recorded in csPCa rates between the two groups (22% vs. 28%; p = 0.47). Limitations of the study are the single-center retrospective nature and the absence of long-term follow-up.

CONCLUSIONS

Confirmatory mpMRI±-targeted biopsies are associated with higher PFS and B-PFS during AS. However, a non-negligible percentage of patients experience csPCa after switching to active treatment.

Prospective evaluation of fexapotide triflutate injection treatment of Grade Group 1 prostate cancer: 4-year results

Purpose

This study was undertaken to determine the safety and efficacy of fexapotide triflutate (FT) 2.5 mg and 15 mg for the treatment of Grade Group 1 prostate cancer.

Methods

Prospective randomized transrectal intraprostatic single injection FT 2.5 mg (n = 49), FT 15 mg (n = 48) and control active surveillance (AS) (n = 49) groups were compared in 146 patients at 28 U.S. sites, with elective AS crossover (n = 18) to FT after first follow-up biopsy at 45 days. Patients were followed for 5 years including biopsies (baseline, 45 days, and 18, 36, and 54 months thereafter), and urological evaluations with PSA every 6 months. Patients with Gleason grade increase or who elected surgical or radiotherapeutic intervention exited the study and were cumulatively included in the data analysis. Percentage of normal biopsies in baseline focus quadrant, tumor grades, and volumes; and outcomes including Gleason grade in entire prostate as well as treated prostate lobe, interventions associated with Gleason grade increase and total incidence of interventions were assessed.

Results

Significantly improved long-term clinical outcomes were found after 4-year follow-up, with percentages of patients progressing to interventions with and without Gleason grade increase significantly reduced by FT single treatment. Results in the FT 15-mg group were superior to the FT 2.5-mg dose group. There were no drug-related serious adverse events (SAEs).

Conclusions

FT showed statistically significant long-term efficacy in the treatment of Grade Group 1 patients regarding clinical and pathological progression. FT 15 mg showed superior results to FT 2.5 mg. There were no drug-related SAEs; FT injection was well tolerated.

Magnetic Resonance Imaging-Guided Confirmatory Biopsy for Initiating Active Surveillance of Prostate Cancer

Importance

Transrectal, ultrasonography-guided prostate biopsy often fails to disclose the severity of underlying pathologic findings for prostate cancer. Magnetic resonance imaging (MRI)-guided biopsy may improve the characterization of prostate pathologic results, but few studies have examined its use for the decision to enter active surveillance.

Objective

To evaluate whether confirmatory biopsy findings by MRI guidance are associated with the risk of pathologic disease upgrading among patients with prostate cancer during active surveillance.

Design, Settings, and Participants

This retrospective cohort study used prospectively obtained registry data from 332 men with prostate cancer of Gleason grade group (GG) 2 or lower who were referred for active surveillance at a large academic medical center from January 1, 2009, through December 31, 2017.

Exposures

All confirmatory and follow-up biopsies were performed using MRI guidance with an MRI-ultrasonography fusion device. Patients underwent repeated MRI-guided biopsies every 12 to 24 months. At follow-up sessions, in addition to obtaining systematic samples, lesions seen on MRI were targeted and foci of low-grade prostate cancer were obtained again using tracking technology. Active surveillance was terminated with detection of at least GG3 disease or receipt of treatment.

Main Outcomes and Measures

The primary outcome was upgrading to at least GG3 disease during active surveillance. Secondary outcomes were the associations of MRI lesion grade, prostate-specific antigen (PSA) level, PSA density, and biopsy method (targeted, systematic, or tracked) with the primary outcome.

Results

Of 332 patients (mean [SD] age, 62.8 [7.6] years), 39 (11.7%) upgraded to at least GG3 disease during follow-up. The incidence of upgrading was 7.9% (9 of 114) when the confirmatory biopsy finding was normal, 11.4% (20 of 175) when the finding showed GG1 disease, and 23.3% (10 of 43) when the finding was GG2 disease (P = .03). Men with GG2 disease were almost 8 times more likely to upgrade during surveillance compared with those with normal findings but only among those with low PSA density (hazard ratio [HR], 7.82; 95% CI, 2.29-26.68). A PSA density of at least 0.15 ng/mL/mL was associated with increased risk of upgrading among patients with normal findings (HR, 7.21; 95% CI, 1.98-26.24) or GG1 disease (HR, 2.86; 95% CI, 1.16 to 7.03) on confirmatory biopsy. A total of 46% of pathologic disease upgrades would have been missed if only the targeted biopsy was performed and 65% of disease upgrades were detected only with tracked biopsy.

Conclusions and Relevance

The findings suggest that confirmatory biopsy with MRI guidance is significantly associated with future disease upgrading of prostate cancer, especially when combined with PSA density, and should be considered as an appropriate entry point for active surveillance. Systematic and targeted biopsies were additive in detection of clinically significant cancers. Repeated biopsy at sites at which findings were previously abnormal (tracking biopsy) facilitated detection of cancers not suitable for continued active surveillance.

MRI to guide biopsies or avoid biopsies?

PURPOSE OF REVIEW

To discuss contemporary data on the value of multiparametric MRI (mpMRI) for guiding the decision to biopsy men at risk for prostate cancer, as well as its utility in active surveillance programs.

RECENT FINDINGS

Although a systematic 12-core biopsy is the current standard of care for men with increased suspicion for prostate cancer, MRI with or without targeted biopsy has been shown to reliably improve the detection of clinically significant disease following a prior negative biopsy. At the same time, there is a growing body of evidence to support the use of MRI for diagnostic purposes in biopsy-naive patients, as well for enrolling and monitoring men on active surveillance programs.

SUMMARY

mpMRI is an evolving technology with great promise for altering our approach to prostate cancer diagnosis and surveillance. In conjunction with targeted biopsies, MRI offers greater specificity for the detection of clinically significant cancer and therefore may help to reduce overdetection of indolent disease while minimizing the risks and limitations of systematic biopsies.

[Active surveillance in prostate cancer]

Prostate cancer remains among the most commonly diagnosed malignancies worldwide in men. In patients with low-risk prostate cancer, the risk of metastasis and mortality is very low; therefore, a tumor surveillance strategy can be used. In patients undergoing active surveillance, curative active therapy is postponed without compromising opportunities for cure until there is evidence of progression or the patient desires active therapy. The aim of active surveillance in prostate cancer patients is to minimize treatment-related toxicity without impairing patient survival. To maintain patients under active surveillance, the following criteria should be met: prostate-specific antigen (PSA) ≤10 ng/ml, Gleason score ≤6, cT1 or cT2a, ≤2 biopsy cores with <50% cancer involvement of every positive core. Follow-up in active surveillance patients is based on repeat biopsy, serial PSA measurements, and digital rectal examination.

Does extent of prostate-specific antigen fluctuation can predict Gleason score upgrading in low-risk prostate cancer patients?

OBJECTIVE

To evaluate the effect of prostate-specific antigen (PSA) fluctuation on Gleason score (GS) upgrading, disease upstaging, oncological outcomes in low-risk prostate cancer (PCa) patients who underwent robot-assisted laparoscopic radical prostatectomy (RARP) and met the inclusion criteria for active surveillance (AS).

MATERIAL AND METHODS

Data of 354 low-risk PCa patients who underwent RARP were retrospectively evaluated. Patients were divided into two groups: PSA fluctuation rate<9.5%/month (Group 1, n=192) and >9.5%/month (Group 2, n=162). Mainly compared parameters were GS upgrading, disease upstaging, biochemical recurrence (BCR) and surgical margin positivity (SMP) rates.

RESULTS

GS upgrading, disease upstaging and SMP were detected in 128 (36.2%), 56 (15.8%) and 42 (11.9%) patients, respectively. After a median follow-up of 46 months, BCR was observed in 40 (11.3%) patients. GS upgrading (41.1% vs. 30.2%, p=0.033), disease upstaging (19.8% vs. 11.1%, p=0.028), SMP (15.1% vs. 8%, p=0.035) and BCR development (15.6% vs. 6.2%, p=0.005) rates were statistically significantly higher in Group 1 than Group 2. In multivariate analysis, digital rectal examination positivity, the presence of two positive cores and low PSA fluctuation rate were found to be significant predictors of GS upgrading.

CONCLUSION

Low PSA fluctuation rate is associated with higher GS upgrading.

Progression and treatment rates using an active surveillance protocol incorporating image-guided baseline biopsies and multiparametric magnetic resonance imaging monitoring for men with favourable-risk prostate cancer

OBJECTIVE

To assess early outcomes since the introduction of an active surveillance (AS) protocol incorporating multiparametric magnetic resonance imaging (mpMRI)-guided baseline biopsies and image-based surveillance.

PATIENTS AND METHODS

A new AS protocol mandating image-guided baseline biopsies, annual mpMRI and 3-monthly prostate-specific antigen (PSA) testing, but which retained protocol re-biopsies, was tested. Pathological progression, treatment conversion and triggers for non-protocol biopsy were recorded prospectively.

RESULTS

Data from 157 men enrolled in the AS protocol (median age 64 years, PSA 6.8 ng/mL, follow-up 39 months) were interrogated. A total of 12 men (7.6%) left the AS programme by choice. Of the 145 men who remained, 104 had re-biopsies either triggered by a rise in PSA level, change in mpMRI findings or by protocol. Overall, 23 men (15.9%) experienced disease progression; pathological changes were observed in 20 men and changes in imaging results were observed in three men. Of these 23 men, 17 switched to treatment, giving a conversion rate of 11.7% (<4% per year). Of the 20 men with pathological progression, this was detected in four of them after a PSA increase triggered a re-biopsy, while in 10 men progression was detected after an mpMRI change. Progression was detected in six men, however, solely after a protocol re-biopsy without prior PSA or mpMRI changes. Using PSA and mpMRI changes alone to detect progression was found to have a sensitivity and specificity of 70.0% and 81.7%, respectively.

CONCLUSION

Our AS protocol, with thorough baseline assessment and imaging-based surveillance, showed low rates of progression and treatment conversion. Changes in mpMRI findings were the principle trigger for detecting progression by imaging alone or pathologically; however, per protocol re-biopsy still detected a significant number of pathological progressions without mpMRI or PSA changes.

The Diverse Genomic Landscape of Clinically Low-risk Prostate Cancer

BACKGROUND

Among men with clinically low-risk prostate cancer, we have previously documented heterogeneity in terms of clinical characteristics and genomic risk scores.

OBJECTIVE

To further study the underlying tumor biology of this patient population, by interrogating broader patterns of gene expression among men with clinically low-risk tumors.

DESIGN, SETTING, AND PARTICIPANTS

Prostate biopsies from 427 patients considered potentially suitable for active surveillance underwent central pathology review and genome-wide expression profiling. These cases were compared with 1290 higher-risk biopsy cases with diverse clinical features from a prospective genomic registry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Average genomic risk (AGR) was determined from 18 published prognostic signatures, and MSigDB hallmark gene sets were analyzed using bootstrapped clustering methods. These sets were examined in relation to clinical variables and pathological and biochemical outcomes using multivariable regression analysis.

RESULTS AND LIMITATIONS

A total of 408 (96%) biopsies passed RNA quality control. Based on AGR quartiles defined by the high-risk multicenter cases, the University of California, San Francisco (UCSF) low-risk patients were distributed across the quartiles as 219 (54%), 107 (26%), 61 (15%), and 21 (5%). Unsupervised clustering analysis of the hallmark gene set scores revealed three clusters, which were enriched for the previously described PAM50 luminal A, luminal B, and basal subtypes. AGR, but not the clusters, was associated with both pathological (odds ratio 1.34, 95% confidence interval [CI] 1.14-1.58) and biochemical outcomes (hazard ratio 1.53, 95% CI 1.19-1.93). These results may underestimate within-prostate genomic heterogeneity.

CONCLUSIONS

Prostate cancers that are homogeneously low risk by traditional characteristics demonstrate substantial diversity at the level of genomic expression. Molecular substratification of low-risk prostate cancer will yield a better understanding of its divergent biology and, in the future may help personalize treatment recommendations.

PATIENT SUMMARY

We studied the genomic characteristics of tumors from men diagnosed with low-risk prostate cancer. We found three main subtypes of prostate cancer with divergent tumor biology, similar to what has previously been found in women with breast cancer. In addition, we found that genomic risk scores were associated with worse pathology findings and prostate-specific antigen recurrence after surgery. These results suggest even greater genomic diversity among low-risk patients than has previously been documented with more limited signatures.

Predictors of adverse pathologic features after radical prostatectomy in low-risk prostate cancer

BACKGROUND

Prostate-specific antigen (PSA) screening more frequently detects early stage prostate cancer (PC). However, adverse pathologic features (APFs) after radical prostatectomy (RP) in low-risk PC occur. Previous related studies had utilized outdated staging criteria or small sample cohorts. In this study, we analyzed predictors of APFs after RP in low-risk PC using classification under the current criteria.

MATERIALS AND METHODS

We retrospectively reviewed medical records of 546 low-risk PC patients who had undergone RP. Low-risk PC was defined as PC with clinical T1-T2a, Gleason score ≤ 6, and PSA levels < 10 ng/mL. Clinical and pathological parameters were analyzed to predict APFs. APFs were defined as extracapsular extension (ECE), seminal vesicle invasion (SVI), or positive surgical margins (PSM). We analyzed our data using univariable and multivariable logistic regression analyses, as well as receiver operator characteristics to predict APFs.

RESULTS

Among 546 patients, ECE, SVI, and PSM were present in 199 (36.4%), 8 (1.5%), and 179 cases (32.8%), respectively. PSM had a significant correlation with preoperative high PSA levels and number of positive cores obtained. ECE/SVI was also significantly correlated with PSA levels and number of positive cores. As a result, presence of APFs after RP was associated with high PSA levels and large number of positive cores. PSA > 4.5 ng/mL and number of positive cores > 2 in low-risk PC were significantly associated with APFs, and suggested as cut-off values for predicting APFs.

CONCLUSIONS

PSA > 4.5 ng/mL and number of positive cores > 2 in low-risk PC were associated with presence of APFs and patients with such records should be considered carefully to provide active surveillance.

Systematic identification of functionally relevant risk alleles to stratify aggressive versus indolent prostate cancer

Novel approaches for classification, including molecular features, are needed to direct therapy for men with low-grade prostate cancer (PCa), especially men on active surveillance. Risk alleles identified from genome-wide association studies (GWAS) could improve prognostication. Those risk alleles that coincided with genes and somatic copy number aberrations associated with progression of PCa were selected as the most relevant for prognostication.

In a systematic literature review, a total of 698 studies were collated. Fifty-three unique SNPs residing in 29 genomic regions, including 8q24, 10q11 and 19q13, were associated with PCa progression. Functional studies implicated 21 of these single nucleotide polymorphisms (SNPs) as modulating the expression of genes in the androgen receptor pathway and several other oncogenes. In particular, 8q24, encompassing MYC, harbours a high density of SNPs conferring unfavourable pathological characteristics in low-grade PCa, while a copy number gain of MYC in low-grade PCa was associated with prostate-specific antigen recurrence after radical prostatectomy.

By combining GWAS data with gene expression and structural rearrangements, risk alleles were identified that could provide a new basis for developing a prognostication tool to guide therapy for men with early prostate cancer.

Prognostic value of urinary prostate cancer antigen 3 (PCA3) during active surveillance of patients with low-risk prostate cancer receiving 5α-reductase inhibitors

OBJECTIVES

To determine the clinical performance of the urinary prostate cancer antigen 3 (PCA3) test to predict the risk of Gleason grade re-classification amongst men receiving a 5α-reductase inhibitor (5ARI) during active surveillance (AS) for prostate cancer.

PATIENTS AND METHODS

Patients with low-risk prostate cancer were enrolled in a prospective Phase II study of AS complemented with prescription of a 5ARI. A repeat biopsy was taken within the first year and annually according to physician and patient preference. In all, 90 patients had urine collected after digital rectal examination of the prostate before the first repeat biopsy. The PCA3 test was performed in a blinded manner at a central laboratory.

RESULTS

Using a PCA3-test score threshold of 35, there was a significant difference (P < 0.001) in the risk of being diagnosed with Gleason ≥7 cancer during a median of 7 years of follow-up. Adjusted Cox regression and Kaplan-Meier analyses also showed a significantly higher risk of upgrading to Gleason ≥7 during follow-up for those with a higher PCA3-test score.

CONCLUSION

The urinary PCA3 test predicted Gleason grade re-classification amongst patients receiving a 5ARI during AS for low-risk prostate cancer.

Cost-effectiveness of a new urinary biomarker-based risk score compared to standard of care in prostate cancer diagnostics - a decision analytical model

OBJECTIVE

To assess the cost-effectiveness of a new urinary biomarker-based risk score (SelectMDx; MDxHealth, Inc., Irvine, CA, USA) to identify patients for transrectal ultrasonography (TRUS)-guided biopsy and to compare this with the current standard of care (SOC), using only prostate-specific antigen (PSA) to select for TRUS-guided biopsy.

MATERIALS AND METHODS

A decision tree and Markov model were developed to evaluate the cost-effectiveness of SelectMDx as a reflex test vs SOC in men with a PSA level of >3 ng/mL. Transition probabilities, utilities and costs were derived from the literature and expert opinion. Cost-effectiveness was expressed in quality-adjusted life years (QALYs) and healthcare costs of both diagnostic strategies, simulating the course of patients over a time horizon representing 18 years. Deterministic sensitivity analyses were performed to address uncertainty in assumptions.

RESULTS

A diagnostic strategy including SelectMDx with a cut-off chosen at a sensitivity of 95.7% for high-grade prostate cancer resulted in savings of €128 and a gain of 0.025 QALY per patient compared to the SOC strategy. The sensitivity analyses showed that the disutility assigned to active surveillance had a high impact on the QALYs gained and the disutility attributed to TRUS-guided biopsy only slightly influenced the outcome of the model.

CONCLUSION

Based on the currently available evidence, the reduction of over diagnosis and overtreatment due to the use of the SelectMDx test in men with PSA levels of >3 ng/mL may lead to a reduction in total costs per patient and a gain in QALYs.

Clinically available RNA profiling tests of prostate tumors: utility and comparison

In the postscreening era, physicians are in need of methods to discriminate aggressive from nonaggressive prostate cancer (PCa) to reduce overdiagnosis and overtreatment. However, studies have shown that prognoses (e.g., progression and mortality) differ even among individuals with similar clinical and pathological characteristics. Existing risk classifiers (TMN grading system, Gleason score, etc.) are not accurately enough to represent the biological features of PCa. Using new genomic technologies, novel biomarkers and classifiers have been developed and shown to add value to clinical or pathological risk factors for predicting aggressive disease. Among them, RNA testing (gene expression analysis) is useful because it can not only reflect genetic variations but also reflect epigenetic regulations. Commercially available RNA profiling tests (Oncotype Dx, Prolaris, and Decipher) have demonstrated strong abilities to discriminate PCa with poor prognosis from less aggressive diseases. For instance, these RNA profiling tests can predict disease progression in active surveillance patients or early recurrence after radical treatments. These tests may offer more dependable methods for PCa prognosis prediction to make more accurate and personal medical decisions.

PRECISION MANAGEMENT OF LOCALIZED PROSTATE CANCER

INTRODUCTION

The vast majority of men who are diagnosed with prostate cancer die of other causes, highlighting the importance of determining which patient has a risk of death from prostate cancer. Precision management of prostate cancer patients includes distinguishing which men have potentially lethal disease and employing strategies for determining which treatment modality appropriately balances the desire to achieve a durable response while preventing unnecessary overtreatment.

AREAS COVERED

In this review, we highlight precision approaches to risk assessment and a context for the precision-guided application of definitive therapy. We focus on three dilemmas relevant to the diagnosis of localized prostate cancer: screening, the decision to treat, and postoperative management.

EXPERT COMMENTARY

In the last five years, numerous precision tools have emerged with potential benefit to the patient. However, to achieve optimal outcome, the decision to employ one or more of these tests must be considered in the context of prevailing conventional factors. Moreover, performance and interpretation of a molecular or imaging precision test remains practitioner-dependent. The next five years will witness increased marriage of molecular and imaging biomarkers for improved multi-modal diagnosis and discrimination of disease that is aggressive versus truly indolent.

Active surveillance for intermediate-risk prostate cancer

Background

Utilization of active surveillance (AS) for prostate cancer is increasing. Optimal selection criteria for this approach are undefined and questions remain on how best to expand inclusion beyond typical men with very low or low risk disease. We sought to review the current experience with AS for men with intermediate risk features.

Methods

Pubmed was queried for all relevant original publications describing outcomes for men with prostate cancer managed with AS. Outcomes for patients with intermediate risk features as defined by the primary investigators were studied when available and compared with similar risk men undergoing immediate treatment.

Results

Cancer specific survival for men managed initially with AS is similar to results published with immediate radical intervention. A total of 5 published AS series describe some outcomes for men with intermediate risk features. Definitions of intermediate risk vary between studies. Men with Gleason 7 disease experience higher rates of clinical progression and are more likely to undergo treatment over time. Intermediate risk men with Gleason 6 disease have similar outcomes to low risk men. Men with Gleason 7 disease appear at higher risk for metastatic disease. Novel technologies including imaging and biomarkers may assist with patient selection and disease surveillance.

Conclusions

The contemporary experiences of AS for men with intermediate risk features suggest that although these men are at higher risk for eventual prostate directed treatment, some are not significantly compromising chances for longer-term cure. Men with more than minimal Gleason pattern 4, however, must be carefully selected and surveyed for early signs of progression and may be at increased risk of metastases. Incorporating information from advanced imaging and biomarker technology will likely individualize future treatment decisions while improving overall surveillance strategies.

New developments in prostate cancer biomarkers

PURPOSE OF REVIEW

The initial management of localized prostate cancer is increasingly complex with the identification of a growing number of prognostic subgroups. Molecular and genetic biomarkers have been proposed to help clinicians and patients navigate treatment decisions.

RECENT FINDINGS

Three commercially available tests, the Genomic Prostate score, Cell Cycle Progression score, and Genomic Classifier appear to currently have the most supporting data for their use in localized prostate cancer. All three have been shown to identify men at higher risk for poor outcome following radical prostatectomy in retrospective studies whereas the first two have also shown promise in addressing which men might be appropriate for active surveillance. Only the Genomic Classifier has data supporting its use as a predictive marker in addition to a prognostic marker.

SUMMARY

Over the past several years, the management of localized prostate cancer has seen the development of several novel biomarkers aimed at improving decision making. Although a lack of prospective validation makes it challenging to know how best to change management based on the results from any of the tests, the growing body of retrospective data suggests significant promise in this arena.

Limiting overdiagnosis of low-risk prostate cancer through an evaluation of the predictive value of transrectal and power Doppler ultrasonography

PURPOSE

Overdiagnosis induced by prostate cancer screening makes necessary a better selection of candidate patients for prostate biopsy. The objective of our study is to assess the probability of having a high- or low-risk lesion that could require active surveillance (AS) after biopsies and a normal or abnormal examination, including transrectal and power Doppler ultrasonography (TRUS-PDS).

METHODS

Four hundred and twenty-nine consecutive patients with a PSA level <10 ng/ml and a normal digital rectal examination (DRE) had guided biopsies in a prospective study. We used D'Amico's criteria to assess the risk of a biological recurrence and Dall'Era's criteria to assess possible AS. The TRUS-PDS was considered positive if one biopsy was positive in the same sextant as the suspect image.

RESULTS

One hundred and seventy-seven out of 429 (41 %) T1c cancers were diagnosed; 131 out of 177 (74 %) could be qualified as low risk, and 119 out of 177 (67 %) could require AS. The TRUS-PDS was normal in 285 of 429 patients (66 %). With a normal TRUS-PDS, the probability of not having cancer with a high or intermediate risk was 96 % (negative predictive value). With an abnormal TRUS-PDS, the probability of having a positive biopsy was 59 %, and the probability of having a significant cancer was 30 %, according to the Dall'Era criteria. When TRUS-PDS was normal, these probabilities significantly decreased to 32 and 5 %, respectively (p < 0.01).

CONCLUSIONS

Patients with a PSA level <10 ng/ml, a normal DRE, and a normal TRUS-PDS have a less than 5 % risk of high- or intermediate-risk cancer.

The importance of active surveillance, and immediate re-biopsy in low-risk prostate cancer: The largest series from Turkey

OBJECTIVE

To evaluate long-term outcomes of active surveillance (AS) applied in low-risk prostate cancer patients, and the impact of re-biopsy results on the prediction of progression.

MATERIAL AND METHODS

In our clinic, patients who had undergone AS for low-risk localized prostate cancer between the years 2005-2013 were included in the study. Our AS criteria are Gleason score ≤6, prostate-specific antigen (PSA) level <10 ng/mL, number of positive cores <3, maximum cancer involvement ratio <50% each core. Immediate re-biopsy (within 3 months) was performed to 65 patients who accepted AS. Finally, 43 patients who met re-biopsy criteria were included in the study. Prostate biopsy specimens were harvested from 12 cores under the guidance of transrectal ultrasound (TRUS). Re-biopsy was performed within 3 months (1-12 weeks). In re-biopsy, a total of 20 core biopsies were performed including the far lateral (6 cores) and transition zone (2 cores) in addition to standard 12 core biopsy. Our follow-up protocol is PSA measurement and digital rectal examination (DRE) every 3 months within the first 2 years, than every 6 months. Control biopsies was performed one year later and once upon every 3 years to patients whose PSA levels and DREs were normal at follow-up visits. More than 2 tumor invaded cores or 50% tumor in one core, and Gleason score exceeding 6 points were accepted as indications for definitive treatment. Patients were divided into two groups by re-biopsy results and compared according to the time to progression. We have done multivariate regression analysis to predict prognosis by using data on age, PSA level, and detection of tumor in re-biopsy specimens.

RESULTS

Patients' median age was 61 years and PSA level was 5 (2.7-9) ng/mL. Tumor was detected in 22 (34%) patients at re-biopsy and they underwent definitive treatment. Additionally tumor was detected in 9 patients, but active surveillance was maintained because their pathologic results met active surveillance criteria. Median follow time was 42 (24-117) months. Definitive treatment was performed in 9 (21%) patients. PSA recurrence was not detected in none of 9 patients during 38 months of follow up. Only the presence of tumor in re-biopsy specimens was found predictor of disease progression in multivariate analysis.

CONCLUSION

We think that AS is safe method for low-risk localized prostate cancer patients, if it is performed in compliance with certain criteria and regular follow up, and early re-biopsy can be useful either during early period or long term follow-up.

A biopsy-integrated algorithm for determining Gleason 6 upgrading risk stratifies risk of active surveillance failure in prostate cancer

INTRODUCTION

A significant proportion of patients that fail active surveillance (AS) for prostate cancer management do so because of cancer upgrading. A previously validated upgrading nomogram generates a score that predicts risk of biopsy Gleason 6 upgrading following radical prostatectomy in lower-risk populations that are candidates for Active Surveillance (Cancer, 2013).

OBJECTIVES

We hypothesize that the upgrading risk (UR) score generated by this nomogram at diagnosis improves the ability to predict patients that will subsequently fail AS.

METHODS

To evaluate the nomogram, retrospective data from several institutional cohorts of patients who met AS criteria, group 1 (n = 75) and group 2 (n = 1230), were independently examined. A UR score was generated using the coefficients from the nomogram consisting of PSA density (PSAD), BMI, maximum % core involvement (MCI), and number of positive cores. AS failure was defined as Gleason score (GS) >6, >50 % maximum core involvement, or >2 positive cores on biopsy. Univariate and multivariate Cox proportional-hazards regression models, upgrading risk score, and other clinicopathologic features were each assessed for their ability to predict AS failure.

RESULTS

Clinicopathologic parameters were similar in both groups with the exception of mean PSAD (0.13 vs. 0.11, p < 0.01) and follow-up (2.1 vs. 3.2 years, p = 0.2). Most common cause of AS failure was GS > 6 (group 1) compared to >2 positive cores (group 2). On univariate analysis in both populations, features at diagnosis including PSAD and the UR score were significant in predicting AS failure by upgrading (Gleason > 6) and any failure. Multivariate analysis revealed the UR score predicts AS failure by GS upgrading (HR 1.8, 95 % CI 1.12-2.93; p = 0.01) and any failure criteria (HR 1.7, 95 % CI 1.06-2.65); p = 0.02) for group 1. Likewise, the UR score in group 2 predicts AS failure with GS upgrading (HR 1.3, 95 % CI 1.15-1.42; p < 0.0001) and any failure criteria (HR 1.18, 95 % CI 1.18-1.38; p < 0.0001). An ROC generated an AUC of 0.66. Decision curve analysis demonstrated a high net benefit for the UR score across a range of threshold probabilities. Based on these outcomes, at 3 years, patients in the lowest risk quartile have a 15 % risk of AS failure versus a 46 % risk in the highest quartile (p < 0.0001).

CONCLUSIONS

The UR score was predictive of pathologic AS failure on multivariate analysis in several AS cohorts. It outperformed single clinicopathologic criteria and may provide a useful adjunct using clinicopathologic data to stratify patients considering AS.

Circulating microRNA signature for the diagnosis of very high-risk prostate cancer

We report the identification of a molecular signature using the Scano-miR profiling platform based on the differential expression of circulating microRNAs (miRNA, miR) in serum samples specific to patients with very high-risk (VHR) prostate cancer (PCa). Five miRNA PCa biomarkers (miR-200c, miR-605, miR-135a*, miR-433, and miR-106a) were identified as useful for differentiating indolent and aggressive forms of PCa. All patients with VHR PCa in the study had elevated serum levels of miR-200c. Circulating miR-433, which was differentially expressed in patients with VHR versus low-risk (LR) forms of PCa, was not detectable by quantitative real-time PCR in samples from healthy volunteers. In blind studies, the five miRNA PCa biomarkers were able to differentiate patients with VHR PCas from those with LR forms as well as healthy individuals with at least 89% accuracy. Biological pathway analysis showed the predictive capability of these miRNA biomarkers for the diagnosis and prognosis of VHR aggressive PCa.

Utility of Gleason pattern 4 morphologies detected on transrectal ultrasound (TRUS)-guided biopsies for prediction of upgrading or upstaging in Gleason score 3 + 4 = 7 prostate cancer

Selected patients with Gleason score (GS) 3 + 4 = 7 prostate cancer (PCa) detected on transrectal ultrasound (TRUS)-guided biopsies may be considered for active surveillance (AS); however, a proportion of these will harbor more aggressive disease. The purpose of this study was to determine if morphologies of Gleason pattern 4 PCa may predict upgrading and/or upstaging after radical prostatectomy (RP). A database search for men with GS 3 + 4 = 7 PCa diagnosed on TRUS-guided biopsy that underwent RP between January 2010 and October 2015 identified 152 patients. Two blinded genitourinary pathologists independently reviewed the biopsies and assessed ill-defined glands (IDG), fused glands, small or large cribriform patterns, and glomerulations. Patient age, serum prostate-specific antigen (PSA), percentage (%) of biopsy sites involved by 3 + 4 = 7 PCa, and overall extent of pattern 4 were also recorded. GS and stage (presence or absence of extraprostatic extension [EPE]) were retrieved from RP reports. Data were compared using independent t tests and chi-square. Inter-observer agreement was calculated using Cohen's Kappa statistic. Percent of biopsy sites and extent of pattern 4 were compared to statistically significant morphologies using the Spearman correlation. 28.3 % (43/152) of patients were upgraded to GS >3 + 4 = 7 at RP (GS 4 + 3 = 7 [N = 17], GS 4 + 3 = 7 with tertiary pattern 5 [N = 25], and GS 4 + 5 = 9 [N = 1]) and 44.1 % (67/152) showed EPE after RP. PSA was associated with both upgrading (8.5 ± 5.4 vs. 6.9 ± 3.2 ng/mL, [p = 0.04]) and EPE (8.2 ± 4.6 vs. 6.7 ± 3.2 ng/mL, [p = 0.03]). IDG, fused glands, and glomerulations were not associated with upgrading or EPE (p > 0.05) with moderate to strong inter-observer agreement (K = 0.76-0.88). There was strong inter-observer agreement for small and large cribriform formations (K = 0.93 and 0.94, respectively) and both patterns were strongly associated with upgrading (p < 0.001) and EPE (p = 0.02) on RP. Strong associations were observed between increasing number of morphologies and both upgrading (p = 0.0.25) and EPE (p < 0.001). Overall extent of pattern 4 was associated with upgrading (p = 0.009) and EPE (p = 0.019) while percent of sites involved by GS 3 + 4 = 7 was only associated with EPE (p = 0.023). Cribriform morphology correlated to percentage of sites with 3 + 4 and overall extent of pattern 4 (rho = 0.25, p = 0.002, rho = 0.20, p = 0.015, respectively). Presence of cribriform morphology on TRUS-guided biopsy is strongly associated with upgrading and upstaging at RP and shows near-perfect inter-observer agreement whereas IDG, fused glands, and glomerulations were not useful. Cribriform morphology may be of importance when considering treatment plans for patients with intermediate risk PCa.

Validation of Selection Criteria for Active Surveillance in Prostate Cancer

INTRODUCTION

Considerable Proportion of Prostate Cancer (PCa) patients suitable for Active Surveillance (AS) harbour aggressive disease at surgical histopathology. Identification of truly indolent prostate cancer at diagnosis is difficult.

AIM

Of this study was to evaluate the accuracy of current AS protocols in identifying low risk PCa by comparing the histopathology at biopsy and surgery.

MATERIALS AND METHODS

A retrospective study was performed on all patients who underwent Radical Prostatectomy (RP) between 2008 and 2012. We identified patients who fulfilled inclusion criteria of five different established AS protocols. Histopathology at biopsy was compared with final surgical histopathology to identify upgrading or upstaging of disease. The biochemical recurrence rate in the cohort was also determined.

RESULTS

A total of 59 patients (24%) met criteria of at least one protocol. Sixteen patients (28%) were eligible for AS based on all studied criteria. Overall 24 patients (40.6%) were upgraded in their final histopathology while 12 patients (20%) upstaged from their original TRUS biopsy. Two patients (3%) had PSA failure, both had salvage radiotherapy.

CONCLUSION

There is considerable discrepency in current AS selection criteria which makes it necessary to introduce novel markers to identify indolent disease as a part of AS protocol for PCa.

Comparative Effectiveness of Targeted Prostate Biopsy Using Magnetic Resonance Imaging Ultrasound Fusion Software and Visual Targeting: a Prospective Study

PURPOSE

We compared the diagnostic outcomes of magnetic resonance-ultrasound fusion and visually targeted biopsy for targeting regions of interest on prostate multiparametric magnetic resonance imaging.

MATERIALS AND METHODS

Patients presenting for prostate biopsy with regions of interest on multiparametric magnetic resonance imaging underwent magnetic resonance imaging targeted biopsy. For each region of interest 2 visually targeted cores were obtained, followed by 2 cores using a magnetic resonance-ultrasound fusion device. Our primary end point was the difference in the detection of high grade (Gleason 7 or greater) and any grade cancer between visually targeted and magnetic resonance-ultrasound fusion, investigated using McNemar's method. Secondary end points were the difference in detection rate by biopsy location using a logistic regression model and the difference in median cancer length using the Wilcoxon signed rank test.

RESULTS

We identified 396 regions of interest in 286 men. The difference in the detection of high grade cancer between magnetic resonance-ultrasound fusion biopsy and visually targeted biopsy was -1.4% (95% CI -6.4 to 3.6, p=0.6) and for any grade cancer the difference was 3.5% (95% CI -1.9 to 8.9, p=0.2). Median cancer length detected by magnetic resonance-ultrasound fusion and visually targeted biopsy was 5.5 vs 5.8 mm, respectively (p=0.8). Magnetic resonance-ultrasound fusion biopsy detected 15% more cancers in the transition zone (p=0.046) and visually targeted biopsy detected 11% more high grade cancer at the prostate base (p=0.005). Only 52% of all high grade cancers were detected by both techniques.

CONCLUSIONS

We found no evidence of a significant difference in the detection of high grade or any grade cancer between visually targeted and magnetic resonance-ultrasound fusion biopsy. However, the performance of each technique varied in specific biopsy locations and the outcomes of both techniques were complementary. Combining visually targeted biopsy and magnetic resonance-ultrasound fusion biopsy may optimize the detection of prostate cancer.

The Efficacy of Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Risk Classification for Patients with Prostate Cancer on Active Surveillance

PURPOSE

We determined whether multiparametric magnetic resonance imaging targeted biopsies may replace systematic biopsies to detect higher grade prostate cancer (Gleason score 7 or greater) and whether biopsy may be avoided based on multiparametric magnetic resonance imaging among men with Gleason 3+3 prostate cancer on active surveillance.

MATERIALS AND METHODS

We identified men with previously diagnosed Gleason score 3+3 prostate cancer on active surveillance who underwent multiparametric magnetic resonance imaging and a followup prostate biopsy. Suspicion for higher grade cancer was scored on a standardized 5-point scale. All patients underwent a systematic biopsy. Patients with multiparametric magnetic resonance imaging regions of interest also underwent magnetic resonance imaging targeted biopsy. The detection rate of higher grade cancer was estimated for different multiparametric magnetic resonance imaging scores with the 3 biopsy strategies of systematic, magnetic resonance imaging targeted and combined.

RESULTS

Of 206 consecutive men on active surveillance 135 (66%) had a multiparametric magnetic resonance imaging region of interest. Overall, higher grade cancer was detected in 72 (35%) men. A higher multiparametric magnetic resonance imaging score was associated with an increased probability of detecting higher grade cancer (Wilcoxon-type trend test p <0.0001). Magnetic resonance imaging targeted biopsy detected higher grade cancer in 23% of men. Magnetic resonance imaging targeted biopsy alone missed higher grade cancers in 17%, 12% and 10% of patients with multiparametric magnetic resonance imaging scores of 3, 4 and 5, respectively.

CONCLUSIONS

Magnetic resonance imaging targeted biopsies increased the detection of higher grade cancer among men on active surveillance compared to systematic biopsy alone. However, a clinically relevant proportion of higher grade cancer was detected using only systematic biopsy. Despite the improved detection of disease progression using magnetic resonance imaging targeted biopsy, systematic biopsy cannot be excluded as part of surveillance for men with low risk prostate cancer.

Reproducibility of Multiparametric Magnetic Resonance Imaging and Fusion Guided Prostate Biopsy: Multi-Institutional External Validation by a Propensity Score Matched Cohort

PURPOSE

As the adoption of magnetic resonance imaging/ultrasound fusion guided biopsy expands, the reproducibility of outcomes at expert centers becomes essential. We sought to validate the comprehensive NCI (National Cancer Institute) experience with multiparametric magnetic resonance imaging and fusion guided biopsy in an external, independent, matched cohort of patients.

MATERIALS AND METHODS

We compared 620 patients enrolled in a prospective trial comparing systematic biopsy to fusion guided biopsy at NCI to 310 who underwent a similar procedure at Long Island Jewish Medical Center. The propensity score, defined as the probability of being treated outside NCI, was calculated using the estimated logistic regression model. Patients from the hospital were matched 1:1 for age, prostate specific antigen, magnetic resonance imaging suspicion score and prior negative biopsies. Clinically significant disease was defined as Gleason 3 + 4 or greater.

RESULTS

Before matching we found differences between the cohorts in age, magnetic resonance imaging suspicion score (each p <0.001), the number of patients with prior negative biopsies (p = 0.01), and the overall cancer detection rate and the cancer detection rate by fusion guided biopsy (each p <0.001). No difference was found in the rates of upgrading by fusion guided biopsy (p = 0.28) or upgrading to clinically significant disease (p = 0.95). A statistically significant difference remained in the overall cancer detection rate and the rate by fusion guided biopsy after matching. On subgroup analysis we found a difference in the overall cancer detection rate and the rate by fusion guided biopsy (p <0.001 and 0.003) in patients with prior negative systematic biopsy but no difference in the 2 rates (p = 0.39 and 0.51, respectively) in biopsy naïve patients.

CONCLUSIONS

Improved detection of clinically significant cancer by magnetic resonance imaging and fusion guided biopsy is reproducible by an experienced multidisciplinary team consisting of dedicated radiologists and urologists.

Can Prostate-Specific Antigen Kinetics before Prostate Biopsy Predict the Malignant Potential of Prostate Cancer?

PURPOSE

To predict the malignant potential of prostate cancer (PCa) according to prostate-specific antigen velocity (PSAV), PSA density (PSAD), free/total PSA ratio (%fPSA), and digital rectal examination (DRE).

MATERIALS AND METHODS

From January 2009 to December 2012, 548 adult male patients were diagnosed with PCa by prostate biopsy at four hospitals in Korea. We retrospectively analyzed 155 adult male patients with an initial PSA level≤10 ng/mL and whose PSA levels had been checked more than two times at least 6 months before they had been diagnosed with PCa, with test intervals of more than 3 months. Patients with a urinary tract infection, and patients who had previously undergone cystoscopy or surgery of the prostate were excluded. We separated patients into two groups according to Gleason sum [Gleason sum≤7 (n=134) or Gleason sum≥8 (n=21)] and the presence of extracapsular invasion [organ confined (n=129) or extracapsular invasion (n=26)]. Differences between the groups were compared.

RESULTS

The group with a Gleason sum≥8 or extracapsular invasion of PCa showed high PSAV and significantly lower %fPSA. There were no significant differences in PSAD and the presence of an abnormality on DRE between two groups.

CONCLUSION

In PCa patients treated with other therapies besides prostatectomy, a high PSA velocity and a low %fPSA may predict high grade PCa with a Gleason sum≥8 or the presence of extracapsular invasion.

Nonvisible tumors on multiparametric magnetic resonance imaging does not predict low-risk prostate cancer

Purpose

To determine whether multiparametric MRI could help predict the diagnosis of low-risk prostate cancer (PCA).

Methods

We retrospectively analyzed consecutive 623 patients with PCA who underwent multiparametric MRI before radical prostatectomy(RP). High-resolution T1- and T2-weighted, diffusion-weighted, and dynamic precontrast and postcontrast image sequences were obtained for each patient. Of the 623 patients, 177(28.4%) exhibited non visible tumors on MRI of clinical stage T1c. The imaging results were compared with the pathological findings with respect to both stage and Gleason scores (GS).

Results

Of the 177 prostatectomy patients with non visible tumors on MRI, pathological findings resulted in the upgrading of 49(27.7%) patients to a sum of GS 7 or more. 101(57.1%) patients exhibited tumor volumes greater than 0.5cc. The biochemical recurrence rate was significantly higher in the pathological upgraded group compared with the nonupgraded group after a mean follow-up time of 29 months. In the multiple logistic analysis, non visible tumor on MRI was not a significant predictor of low-risk PCA.

Conclusions

Even though cancer foci were not visualized by postbiopsy MRI, the pathological tumor volumes and extent of GS upgrading were relatively high. Therefore, nonvisible tumors by multiparametric MRI do not appear to be predictive of low-risk PCA.