The Epstein Criteria Predict for Organ-Confined But Not Insignificant Disease and a High Likelihood of Cure at Radical Prostatectomy

Genome-wide methylation profiling of diagnostic tumor specimens identified DNA methylation markers associated with metastasis among men with untreated localized prostate cancer

BACKGROUND

We used a genome-wide discovery approach to identify methylation markers associated with metastasis in men with localized prostate cancer (PCa), as better identification of those at high risk of metastasis can inform treatment decision-making.

METHODS

We identified men with localized PCa at Kaiser Permanente California (January 1, 1997-December 31, 2006) who did not receive curative treatment and followed them for 10 years to determine metastasis status. Cases were chart review-confirmed metastasis, and controls were matched using density sampling. We extracted DNA from the cancerous areas in the archived diagnostic tissue blocks. We used Illumina's Infinium MethylationEPIC BeadChip for methylation interrogation. We used conditional logistic regression and Bonferroni's correction to identify methylation markers associated with metastasis. In a separate validation cohort (2007), we evaluated the added predictive utility of the methylation score beyond clinical risk score.

RESULTS

Among 215 cases and 404 controls, 31 CpG sites were significantly associated with metastasis status. Adding the methylation score to the clinical risk score did not meaningfully improve the c-statistic (0.80-0.81) in the validation cohort, though the score itself was statistically significant (p < 0.01). In the validation cohort, both clinical risk score alone and methylation marker score alone are well calibrated for predicted 10-year metastasis risks. Adding the methylation score to the clinical risk score only marginally improved predictive risk calibration.

CONCLUSION

Our findings do not support the use of these markers to improve clinical risk prediction. The methylation markers identified may inform novel hypothesis in the roles of these genetic regions in metastasis development.

Conditional survival of patients with low-risk prostate cancer: Temporal changes in active surveillance permanence over time

PURPOSE

To determine risk categories for patients with prostate cancer (PCa) in active surveillance (AS) and to test the conditional survival (CS) that examined the effect of event-free survival since AS-entrance.

MATERIALS AND METHODS

From January 2012 to December 2020 we analyzed 606 patients with PCa enrolled in our AS program. Kaplan-Meier (KM) plots depicted AS-exit rate. Multivariable Cox regression models (MCRMs) tested for AS-exit rate independent predictors to determine risk categories. CS estimates were used to calculate overall AS-exit rate after event-free survival intervals of 1, 2, 3, and 5 years, and after stratification according to risk categories.

RESULTS

At MCRMs PSAd ≥ 0.15 (HR: 1.43; P-value 0.04), PI-RADS 4-5 (HR: 2.56; P-value <0.001) and number of biopsy positive cores ≥ 2 (HR: 1.75; P-value <0.001) were independent predictors of AS-exit. These variables were used to determine risk categories: low-, intermediate- and high-risk. Overall, according to CS-analyses, 5-year AS-exit free rate increased from 59.7% at baseline, to 67.3%, 74.7%, and 89.4% in patients who remained in AS respectively ≥1, ≥2, ≥3 and ≥5 years. After stratification according to risk categories, in those patients who remained in AS ≥ 5 years, 5-year AS-exit free rates increased from 76.3% to 100% in patients with a low-risk, from 62.7% to 83.7% in patients with an intermediate-risk and from 42.3% to 87.5% in patients with a high-risk.

CONCLUSIONS

CS models showed a direct relationship between event-free survival duration and subsequent AS permanence in overall PCa patients and after stratification according to risk categories.

Association between previous negative biopsies and lower rates of progression during active surveillance for prostate cancer

Purpose

To test any-cause discontinuation and ISUP GG upgrading rates during Active Surveillance (AS) in patients that underwent previous negative biopsies (PNBs) before prostate cancer (PCa) diagnosis vs. biopsy naive patients.

Methods

Retrospective analysis of 961 AS patients (2008–2020). Three definitions of PNBs were used: (1) PNBs status (biopsy naïve vs. PNBs); (2) number of PNBs (0 vs. 1 vs. ≥ 2); (3) histology at last PNB (no vs. negative vs. HGPIN/ASAP). Kaplan–Meier plots and multivariable Cox models tested any-cause and ISUP GG upgrading discontinuation rates.

Results

Overall, 760 (79.1%) vs. 201 (20.9%) patients were biopsy naïve vs. PNBs. Specifically, 760 (79.1%) vs. 138 (14.4%) vs. 63 (6.5%) patients had 0 vs. 1 vs. ≥ 2 PNBs. Last, 760 (79.1%) vs. 134 (13.9%) vs. 67 (7%) patients had no vs. negative PNB vs. HGPIN/ASAP. PNBs were not associated with any-cause discontinuation rates. Conversely, PNBs were associated with lower rates of ISUP GG upgrading: (1) PNBs vs. biopsy naïve (HR:0.6, p = 0.04); (2) 1 vs. 0 PNBs (HR:0.6, p = 0.1) and 2 vs. 0 PNBs, (HR:0.5, p = 0.1); (3) negative PNB vs. biopsy naïve (HR:0.7, p = 0.3) and HGPIN/ASAP vs. biopsy naïve (HR:0.4, p = 0.04). However, last PNB ≤ 18 months (HR:0.4, p = 0.02), but not last PNB > 18 months (HR:0.8, p = 0.5) were associated with lower rates of ISUP GG upgrading.

Conclusion

PNBs status is associated with lower rates of ISUP GG upgrading during AS for PCa. The number of PNBs and time from last PNB to PCa diagnosis (≤ 18 months) appear also to be critical for patient selection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-03983-8.

Diagnostic Accuracy of Contemporary Selection Criteria in Prostate Cancer Patients Eligible for Active Surveillance: A Bayesian Network Meta-Analysis

Background

Several active surveillance (AS) criteria have been established to screen insignificant prostate cancer (insigPCa, defined as organ confined, low grade and small volume tumors confirmed by postoperative pathology). However, their comparative diagnostic performance varies. The aim of this study was to compare the diagnostic accuracy of contemporary AS criteria and validate the absolute diagnostic odds ratio (DOR) of optimal AS criteria.

Methods

First, we searched Pubmed and performed a Bayesian network meta-analysis (NMA) to compare the diagnostic accuracy of contemporary AS criteria and obtained a relative ranking. Then, we searched Pubmed again to perform another meta-analysis to validate the absolute DOR of the top-ranked AS criteria derived from the NMA with two endpoints: insigPCa and favorable disease (defined as organ confined, low grade tumors). Subgroup and meta-regression analyses were conducted to identify any potential heterogeneity in the results. Publication bias was evaluated.

Results

Seven eligible retrospective studies with 3,336 participants were identified for the NMA. The diagnostic accuracy of AS criteria ranked from best to worst, was as follows: Epstein Criteria (EC), Yonsei criteria, Prostate Cancer Research International: Active Surveillance (PRIAS), University of Miami (UM), University of California-San Francisco (UCSF), Memorial Sloan-Kettering Cancer Center (MSKCC), and University of Toronto (UT). I² = 50.5%, and sensitivity analysis with different insigPCa definitions supported the robustness of the results. In the subsequent meta-analysis of DOR of EC, insigPCa and favorable disease were identified as endpoints in ten and twenty-two studies, respectively. The pooled DOR for insigPCa and favorable disease were 0.44 (95%CI, 0.31–0.58) and 0.66 (95%CI, 0.61–0.71), respectively. According to a subgroup analysis, the DOR for favorable disease was significantly higher in US institutions than that in other regions. No significant heterogeneity or evidence of publication bias was identified.

Conclusions

Among the seven AS criteria evaluated in this study, EC was optimal for positively identifying insigPCa patients. The pooled diagnostic accuracy of EC was 0.44 for insigPCa and 0.66 when a more liberal endpoint, favorable disease, was used.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], PROSPERO [CRD42020157048].

The Epstein criteria predict for organ-confined prostate cancer but not for minimal residual disease and outcome after radical prostatectomy

OBJECTIVE

The Epstein criteria (EC) used to select men for active surveillance do not predict biologically insignificant diseases. Minimal residual disease (MRD) is an undetected microscopic disease that remains after radical prostectomy (RP) and is a biological classification associated with the risk of treatment failure. Subtypes of MRD, the 10-year biochemical failure free survival (BFFS), and restricted mean biochemical failure free survival time (RMST) were determined and compared in EC patients treated with RP.

MATERIAL AND METHODS

Consecutive patients with a Gleason 6 biopsy treated at a single institution were divided into those who did or did not fulfill the EC and underwent RP. One month after surgery, samples were taken for the detection of circulating prostate cells (CPCs) and bone marrow micrometastasis. MRD was defined as negative for both CPCs and micrometastasis; patients were positive for micrometastasis and CPCs separately. BFFS for up to 10 years and RMST were determined for each MRD subgroup for EC positive and negative patients.

RESULTS

EC positive men (137/426) were significantly older (p<0.05) and had negative MRD, pT2 (pathologically organ confined) disease (<0.02), and lower frequency of upgrading (p<0.02). Of the EC positive men, 71% were MRD negative, 13% were positive for micrometastasis, and 16% were positive for CPCs with respective 10-year BFFS of 99%, 89%, and 21% (<0.001) (hazard ratio: 1.00, 1.76, 4.03, respectively) with no signficant differences between the 10-year BFFS or RMST for MRD subgroups for EC positive and negative patients.

CONCLUSIONS

EC predict pT2, MRD negative disease; however, 29% are MRD positive with a high risk of treatment failure.

Predicting Insignificant Prostate Cancer: Analysis of the Pathological Outcomes of Candidates for Active Surveillance according to the Pre-International Society of Urological Pathology (Pre-ISUP) 2014 Era Versus the Post-ISUP2014 Era

Purpose

To analyze the difference in the prediction accuracy with an active surveillance (AS) protocol between two eras (pre-International Society of Urological Pathology [pre-ISUP]-2014 vs. post-ISUP2014).

Materials and Methods

We retrospectively analyzed 118 candidates for AS who underwent radical prostatectomy between 2009 and 2017. We divided our patients into two groups (group 1 [n=57], operation date 2009–2015; group 2 [n=61], operation date 2016–2017). Pathologic slides in group 1 were reviewed to distinguish men with cribriform pattern (CP) because the determination of Gleason scores in old era had been based on pre-ISUP2014 classification. Postoperative outcomes in the two eras were analyzed twice: first, all men in group 1 vs. group 2; second, the remaining men after excluding those with CPs in group 1 vs. group 2.

Results

The proportion of men with insignificant prostate cancer (iPCa) was significantly lower in group 1 than in group 2 (36.8% vs. 57.4%, p=0.040). After excluding 11 men with CPs from group 1, those remaining (46 men) were compared again with group 2. In this analysis, the proportion of men with iPCa was similar between the two groups (old vs. contemporary era: 41.3% vs. 57.4%, p=0.146). Nine of 11 men with CP had violated the criteria for iPCa in the earlier comparison.

Conclusions

The accuracy of the AS protocol has been affected by the coexistence of CPs and pure Gleason 6 tumors in the pre-ISUP2014 era. We suggest to use only contemporary (post-ISUP2014) data to analyze the accuracy with AS protocols in future studies.

Utilization of Multiparametric MRI of Prostate in Patients under Consideration for or Already in Active Surveillance: Correlation with Imaging Guided Target Biopsy

This study sought to assess the value of multiparametric magnetic resonance image (mp-MRI) in patients with a prostate cancer (PCa) Gleason score of 6 or less under consideration for or already in active surveillance and to determine the rate of upgrading by target biopsy. Three hundred and fifty-four consecutive men with an initial transrectal ultrasound-guided (TRUS) biopsy-confirmed PCa Gleason score of 6 or less under clinical consideration for or already in active surveillance underwent mp-MRI and were retrospectively reviewed. One hundred and nineteen of 354 patients had cancer-suspicious regions (CSRs) at mp-MRI. Each CSR was assigned a Prostate Imaging Reporting and Data System (PI-RADS) score based on PI-RADS v2. One hundred and eight of 119 patients underwent confirmatory imaging-guided biopsy for CSRs. Pathology results including Gleason score (GS) and percentage of specimens positive for PCa were recorded. Associations between PI-RADS scores and findings at target biopsy were evaluated using logistic regression. At target biopsy, 81 of 108 patients had PCa (75%). Among them, 77 patients had upgrading (22%, 77 of 354 patients). One hundred and forty-six CSRs in 108 patients had PI-RADS 3 n = 28, 4 n = 66, and 5 n = 52. The upgraded rate for each category of CSR was for PI-RADS 3 (5 of 28, 18%), 4 (47 of 66, 71%) and 5 (49 of 52, 94%). Using logistic regression analysis, differences in PI-RADS scores from 3 to 5 are significantly associated with the probability of disease upgrade (20%, 73%, and 96% for PI-RADS score of 3, 4, and 5, respectively). Adding mp-MRI to patients under consideration for or already in active surveillance helps to identify undiagnosed PCa of a higher GS or higher volume resulting in upgrading in 22%.

Multiparametric magnetic resonance imaging and clinical variables: Which is the best combination to predict reclassification in active surveillance patients?

Introduction & objectives

We tested the role of multiparametric magnetic resonance imaging (mpMRI) in disease reclassification and whether the combination of mpMRI and clinicopathological variables could represent the most accurate approach to predict the risk of reclassification during active surveillance.

Materials & methods

Three-hundred eighty-nine patients (pts) underwent mpMRI and subsequent confirmatory or follow-up biopsy according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol. Pts with negative (−) mpMRI underwent systematic random biopsy. Pts with positive (+) mpMRI [Prostate Imaging Reporting and Data System, version 2 (PI-RADS-V2) score ≥3] underwent targeted + systematic random biopsies. Multivariate analyses were used to create three models predicting the probability of reclassification [International Society of Urological Pathology ≥ Grade Group 2 (GG2)]: a basic model including only clinical variables (age, prostate-specific antigen density, and number of positive cores at baseline), an Magnetic resonance imaging (MRI) model including only the PI-RADS score, and a full model including both the previous ones. The predictive accuracy (PA) of each model was quantified using the area under the curve.

Results

mpMRI negative (−) was recorded in 127 (32.6%) pts; mpMRI positive (+) was recorded in 262 pts: 72 (18.5%) had PI-RADS 3, 150 (38.6%) PI-RADS 4, and 40 (10.3%) PI-RADS 5 lesions. At a median follow-up of 12 months, 125 pts (32%) were reclassified to GG2 prostate cancer. The rate of reclassification to GG2 prostate cancer was 17%, 35%, 38%, and 52% for mpMRI (−), PI-RADS 3, 4, and 5, respectively (P < 0.001). The PA was 69% and 64% in the basic and MRI models, respectively. The full model had the best PA of 74%: older age (P = 0.023; Odds ratio (OR) = 1.040), prostate-specific antigen density (P = 0.037; OR = 1.324), number of positive cores at baseline (P = 0.001; OR = 1.441), and PI-RADS 3, 4, and 5 (overall P = 0.001; OR = 2.458, 3.007, and 3.898, respectively) were independent predictors of reclassification.

Conclusions

Disease reclassification increased according to the PI-RADS score increase, at confirmatory or follow-up biopsy. However, a no-negligible rate of reclassification was found also in cases of mpMRI (−). The combination of mpMRI and clinicopathological variables still represents the most accurate approach to pts on active surveillance.

The Use of Multiparametric Magnetic Resonance Imaging for Follow-up of Patients Included in Active Surveillance Protocol. Can PSA Density Discriminate Patients at Different Risk of Reclassification?

INTRODUCTION

The objective of this study was to test Prostate Imaging Reporting and Data System (PI-RADS) classification on multiparametric magnetic resonance imaging (mpMRI) and MRI-derived prostate-specific antigen density (PSAD) in predicting the risk of reclassification in men in active surveillance (AS), who underwent confirmatory or per-protocol follow-up biopsy.

MATERIALS AND METHODS

Three hundred eighty-nine patients in AS underwent mpMRI before confirmatory or follow-up biopsy. Patients with negative (-) mpMRI underwent systematic random biopsy. Patients with positive (+) mpMRI underwent targeted fusion prostate biopsies + systematic random biopsies. Different PSAD cutoff values were tested (< 0.10, 0.10-0.20, ≥ 0.20). Multivariable analyses assessed the risk of reclassification, defined as clinically significant prostate cancer of grade group 2 or more, during follow-up according to PSAD, after adjusting for covariates.

RESULTS

One hundred twenty-seven (32.6%) patients had mpMRI(-); 72 (18.5%) had PI-RADS 3, 150 (38.6%) PI-RADS 4, and 40 (10.3%) PI-RADS 5 lesions. The rate of reclassification to grade group 2 PCa was 16%, 22%, 31%, and 39% for mpMRI(-) and PI-RADS 3, 4, and 5, respectively, in case of PSAD < 0.10 ng/mL²; 16%, 25%, 36%, and 44%, in case of PSAD 0.10 to 0.19 ng/mL²; and 25%, 42%, 55%, and 67% in case of PSAD ≥ 0.20 ng/mL². PSAD ≥ 0.20 ng/mL² (odds ratio [OR], 2.45; P = .007), PI-RADS 3 (OR, 2.47; P = .013), PI-RADS 4 (OR, 2.94; P < .001), and PI-RADS 5 (OR, 3.41; P = .004) were associated with a higher risk of reclassification.

CONCLUSION

PSAD ≥ 0.20 ng/mL² may improve predictive accuracy of mpMRI results for reclassification of patients in AS, whereas PSAD < 0.10 ng/mL² may help selection of patients at lower risk of harboring clinically significant prostate cancer. However, the risk of reclassification is not negligible at any PSAD cutoff value, also in the case of mpMRI(-).

Multiparametric Magnetic-Resonance to Confirm Eligibility to an Active Surveillance Program for Low-Risk Prostate Cancer: Intermediate Time Results of a Third Referral High Volume Centre Active Surveillance Protocol

BACKGROUND

To evaluate the role of confirmatory multiparametric magnetic resonance imaging (mpMRI) of the prostate at the time of Active Surveillance (AS) enrollment to reduce disease misclassification.

MATERIALS

From 2012 to 2016, 383 patients with low-risk disease respecting Prostate Cancer Research International AS criteria underwent confirmatory 1.5-T mpMRI. AS was proposed to patients with Prostate Imaging and Report and Data System (PI-RADS) score ≤3 and no extraprostatic extension (EPE), whereas patients with PI-RADS score ≥4 and/or EPE were treated actively. Kaplan-Meier analyses quantified progression-free survival (PFS) in patients enrolled in the AS program. Logistic regression analyses tested the association between confirmatory mpMRI and clinically significant prostate cancer (csPCa) at radical prostatectomy (RP). Diagnostic performance of mpMRI was calculated in patients submitted to immediate RP.

RESULTS

PFS rate was 99, 90 and 86% at 1, 2 and 3 years respectively. At multivariable analysis, PI-RADS 3, PI-RADS 4, PI-RADS 5 and EPE increased the probability of having csPCa at immediate RP (PI-RADS 3 [OR] 1.2, p = 0.26; PI-RADS 4 [OR] 5.1, p = 0.02; PI-RADS 5 [OR] 6.7; p = 0.009; EPE [OR] 11.8, p < 0.001). Confirmatory mpMRI showed sensibility, specificity, positive predictive value and negative predictive value of 85, 55, 68 and 76% respectively.

CONCLUSIONS

MpMRI at the time of AS enrollment reduces the misclassification rate of csPCa. We suggest to perform target biopsies in patients with PI-RADS score 3 and 4 lesions.

Functional outcomes of robot-assisted radical prostatectomy in patients eligible for active surveillance

OBJECTIVE

To assess the outcome of low risk prostate cancer (PCa) patients who were candidates for active surveillance (AS) but had undergone robot-assisted radical prostatectomy (RARP).

METHOD

We reviewed our prospectively collected database of patients operated by RARP between 2006 and 2014. Low D'Amico risk patients were selected. Oncological outcomes were reported based on pathology results and biochemical failure. Functional outcomes on continence and potency were reported at 12 and 24 months. Continence was assessed by the number of pads per day. With respect to potency, it was assessed using the Sexual Health Inventory for Men (SHIM) and Erectile Hardness Scale (EHS).

RESULTS

Out of 812 patients, 237 (29.2%) patients were D'Amico low risk and were eligible for analysis. 44 men fit Epstein's criteria. 134 (56.5%) men had pathological upgrading. Age and clinical stage were predictors of upgrading on multivariate analysis. 220 (92.8%) patients had available follow-up for biochemical recurrence, potency, and continence for 2 years. The mean and median follow-up was 34.8 and 31.4 months, respectively. Only 5 (2.3%) men developed BCR, all of whom had pathological upgrading. Extra capsular extension and positive surgical margins were observed in 14.8 and 19.1%, respectively. 0 pad was achieved in 86.7 and 88.9% at 1 and 2 years, respectively. Proportion of patients with SHIM > 21 at 1 and 2 years was 24.8 and 30.6%, respectively. Moreover, patients having erections adequate for intercourse (EHS ≥ 3) were seen in 69.6 and 83.1% at 1 and 2 years, respectively. Functional outcomes of patients fitting Epstein's criteria (n = 44) and patients with no upgrading on final pathology (n = 103) were not significantly different compared to the overall low risk study group.

CONCLUSION

This retrospective study showed that RARP is not without harm even in patients with low risk disease. On the other hand, considerable rate of upgrading was noted.

MR-guided biopsy and focal therapy: new options for prostate cancer management

PURPOSE OF REVIEW

Options for prostate cancer management are rapidly expanding. The recent advent of MRI technology has led to guided prostate biopsies by radiologists working in-bore or by urologists using MR/US fusion technology. The resulting tumor visualization now provides the option of focal therapy. Currently available are highly directed energies - focused ultrasound (HIFU), cryotherapy, and laser - all offering the hope of curing prostate cancer with few side effects.

RECENT FINDINGS

MRI now enables visualization of many prostate cancers. MR/US fusion biopsy makes possible the targeted biopsy of suspicious lesions efficiently in the urology clinic. Several fusion devices are now commercially available. Focal therapy, a derivative of targeted biopsy, is reshaping the approach to treatment of some prostate cancers. Focal laser ablation, originally done in the MRI gantry (in-bore), promises to soon become feasible in a clinic setting (out-of-bore) under local anesthesia. Other focal therapy options, including HIFU and cryotherapy, are currently available. Herein are summarized outcomes data on focal therapy modalities.

SUMMARY

MRI-guided biopsy is optimizing prostate cancer diagnosis. Focal therapy, an outgrowth of guided biopsy, promises to become a well tolerated and effective approach to treating many men with prostate cancer while minimizing the risks of incontinence and impotence from radical treatment.

Prostate Biopsy in Active Surveillance Protocols: Immediate Re-biopsy and Timing of Subsequent Biopsies

PURPOSE OF REVIEW

This manuscript reviews contemporary literature regarding prostate cancer active surveillance (AS) protocols as well as other tools that may guide the management of biopsy frequency and assess the possibility of progression in low-risk prostate cancer.

RECENT FINDINGS

There is no consensus regarding the timing of surveillance biopsies; however, an immediate repeat biopsy within 12 months of diagnosis for patients considering AS confirms patients who have favorable risk disease yet also identifies patients who were undersampled initially. Studies regarding multiparametric MRI, nomograms, and biomarkers show promise in risk stratifying and counseling patients during AS. Further studies are needed to determine if these supplemental tests can decrease the frequency of surveillance biopsies. An immediate re-biopsy can help to reduce the risk of missing clinically significant disease. Other clinical tools, including mpMRI, exist that can be used as an adjunct to counsel patients and guide a personalized discussion regarding the frequency of surveillance biopsies.

Targeted Prostate Biopsy in the Era of Active Surveillance

Targeted prostate biopsy using magnetic resonance imaging (MRI) guidance is improving the accuracy of prostate cancer (CaP) diagnosis. This new biopsy technology is especially important for men undergoing active surveillance, improving patient selection for enrollment and enabling precise longitudinal monitoring. Magnetic resonance imaging/ultrasound fusion biopsy allows for 3 functions not previously possible with US-guided biopsy: targeting of suspicious regions, template-mapping for systematic sampling, and tracking of cancer foci over time. This article reviews the evolving role of the new biopsy methods in active surveillance, including the UCLA Active Surveillance pathway, which has incorporated magnetic resonance imaging/ultrasound fusion biopsy from program inception as a possible model.

Stricter Active Surveillance Criteria for Prostate Cancer do Not Result in Significantly Better Outcomes: A Comparison of Contemporary Protocols

PURPOSE

We reviewed various existing active surveillance criteria and determined the competing trade-offs of the stricter vs more inclusive active surveillance criteria.

MATERIALS AND METHODS

Men enrolled in an active surveillance program at Princess Margaret Cancer Centre between 1998 and 2014 were identified through a prospectively maintained database. All patients were assessed for entry eligibility into the Prostate Cancer Research International: Active Surveillance, Johns Hopkins, University of Miami, University of California San Francisco, Memorial Sloan Kettering Cancer Center, University of Toronto-Sunnybrook and Royal Marsden protocols. The 2-sided t-test, ANOVA, Wilcoxon rank sum or chi-square tests were used for comparison as appropriate.

RESULTS

Of the 1,365 men identified 1,085 met the Princess Margaret Cancer Centre inclusion criteria. When the Johns Hopkins, Prostate Cancer Research International: Active Surveillance and University of Miami criteria were applied 15.2%, 11.5% and 11.3% of these patients were excluded from active surveillance, respectively. No significant differences were noted between men who met the Princess Margaret Cancer Centre criteria and those who were excluded based on more stringent criteria when grade or volume reclassification was compared. No significant differences in prostate specific antigen velocity or the number of patients who proceeded to seek treatment were noted (p >0.1). Rates of biochemical recurrence among patients who chose to undergo radical prostatectomy after initial active surveillance were not different between men who met the more inclusive vs more exclusive active surveillance protocols.

CONCLUSIONS

More selective criteria do not significantly improve short-term outcomes when considering the relative risk of grade reclassification or biochemical failure after treatment. In an era of increased awareness regarding the over diagnosis and overtreatment of prostate cancer, we believe that stricter entry criteria should be reconsidered.

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.

Active surveillance for prostate cancer: can we modernize contemporary protocols to improve patient selection and outcomes in the focal therapy era?

PURPOSE OF REVIEW

In the absence of whole gland treatment for prostate cancer, both active surveillance and focal therapy share the common need of requiring a more thorough, detailed and precise analysis of the biological threats within the prostatic parenchyma if one chooses to monitor or selectively eradicate only specific neoplastic targets. In addition, focal therapy utilizes active surveillance post-treatment to monitor the untreated sectors of the prostate. We aim to evaluate the current modalities available to modernize active surveillance protocols in order to distinguish patients who may be safely observed from those who require intervention.

RECENT FINDINGS

Traditional active surveillance protocols by today's standards are rudimentary given the rapidly evolving technologies now available to clinicians. There is growing evidence for the adoption and use of multiparametric MRI and MRI-targeted biopsy to identify and localize prostate cancers of higher stage and grade. In addition, serum markers and prostate tissue DNA, RNA and methylation markers provide novel information that extends beyond Gleason grade to better characterize and define prostate cancer prognosis. Current active surveillance protocols should incorporate these modalities to improve patient stratification to surveillance, focal or whole gland interventions.

SUMMARY

Active surveillance protocols should be modernized to include cancer localization modalities and molecular prognostic markers to improve tumour characterization and better stratify men to surveillance, focal or radical intervention.

The value of magnetic resonance imaging and ultrasonography (MRI/US)-fusion biopsy platforms in prostate cancer detection: a systematic review

Despite limitations considering the presence, staging and aggressiveness of prostate cancer, ultrasonography (US)-guided systematic biopsies (SBs) are still the 'gold standard' for the diagnosis of prostate cancer. Recently, promising results have been published for targeted prostate biopsies (TBs) using magnetic resonance imaging (MRI) and ultrasonography (MRI/US)-fusion platforms. Different platforms are USA Food and Drug Administration registered and have, mostly subjective, strengths and weaknesses. To our knowledge, no systematic review exists that objectively compares prostate cancer detection rates between the different platforms available. To assess the value of the different MRI/US-fusion platforms in prostate cancer detection, we compared platform-guided TB with SB, and other ways of MRI TB (cognitive fusion or in-bore MR fusion). We performed a systematic review of well-designed prospective randomised and non-randomised trials in the English language published between 1 January 2004 and 17 February 2015, using PubMed, Embase and Cochrane Library databases. Search terms included: 'prostate cancer', 'MR/ultrasound(US) fusion' and 'targeted biopsies'. Extraction of articles was performed by two authors (M.G. and A.A.) and were evaluated by the other authors. Randomised and non-randomised prospective clinical trials comparing TB using MRI/US-fusion platforms and SB, or other ways of TB (cognitive fusion or MR in-bore fusion) were included. In all, 11 of 1865 studies met the inclusion criteria, involving seven different fusion platforms and 2626 patients: 1119 biopsy naïve, 1433 with prior negative biopsy, 50 not mentioned (either biopsy naïve or with prior negative biopsy) and 24 on active surveillance (who were disregarded). The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was used to assess the quality of included articles. No clear advantage of MRI/US fusion-guided TBs was seen for cancer detection rates (CDRs) of all prostate cancers. However, MRI/US fusion-guided TBs tended to give higher CDRs for clinically significant prostate cancers in our analysis. Important limitations of the present systematic review include: the limited number of included studies, lack of a general definition of 'clinically significant' prostate cancer, the heterogeneous study population, and a reference test with low sensitivity and specificity. Today, a limited number of prospective studies have reported the CDRs of fusion platforms. Although MRI/US-fusion TB has proved its value in men with prior negative biopsies, general use of this technique in diagnosing prostate cancer should only be performed after critical consideration. Before bringing MRI/US fusion-guided TB in to general practice, there is a need for more prospective studies on prostate cancer diagnosis.

Apparent diffusion coefficient value and ratio as noninvasive potential biomarkers to predict prostate cancer grading: comparison with prostate biopsy and radical prostatectomy specimen

OBJECTIVE. The purpose of this study is to test the association between diffusion-weighted MRI and prostate cancer Gleason score at both biopsy and final pathologic analysis after radical prostatectomy. SUBJECTS AND METHODS. Patients with prostate cancer (n = 72) underwent diffusion-weighted MRI (b values, 0, 800, and 1600 s/mm(2)) with an endorectal coil. Apparent diffusion coefficient (ADC) and ADC ratio were obtained in normal and pathologic tissue and were correlated with transrectal ultrasound-guided biopsy (n = 72) and histopathologic (n = 39) Gleason scores using the ANOVA test. ADC accuracy was estimated using ROC curves. RESULTS. Lesions suspicious for prostate cancer were detected in 65 patients. The mean ADC was 1.47 and 0.87 × 10(-3) mm(2)/s for normal and pathologic tissue, respectively (p < 0.001). When we divided the population into four groups (normal tissue and biopsy Gleason scores of 6, 7, and 8-10), then the mean ADC value was 1.47, 0.96, 0.80, and 0.78 × 10(-3) mm(2)/s, respectively (p < 0.001). The ADC ratio decreased along with an increase in biopsy Gleason score (66.9%, 56.7%, and 51.5% for Gleason scores of 6, 7 and 8-10, respectively) (ANOVA, p = 0.003) and pathologic Gleason score (ANOVA, p < 0.001). ROC curves had an AUC of 0.94 and 0.86 for ADC and ADC ratio, respectively (p = 0.012 and 0.042, respectively). CONCLUSION. Decreasing ADC values may represent a strong risk factor of harboring a poorly differentiated prostate cancer, independently of biopsy characteristics.

The effect of urologist experience on choosing active surveillance for prostate cancer

PURPOSE

To evaluate the impact of the urologist's experience in selecting active surveillance (AS) versus immediate treatment (IT) for low-risk prostate cancer.

METHODS

Men with low-risk prostate cancer were enrolled from March 2011 to August 2013 at 13 medical centers in Kaiser Permanente Southern California. The AS cohort was defined as men who had cT1-T2a stage prostate cancer, prostate-specific antigen <10 ng/ml, a biopsy revealing Gleason grade ≤6, fewer than three biopsy cores positive, ≤50 % cancer in any core, and not undergone immediate therapy (surgery, radiation, other) within 6 months following diagnosis. The urologist's experience (age, number of years in practice, number of robotic surgeries performed, and fellowship experience in oncology and/or robotics) was then compared between AS and IT cohorts.

RESULTS

A total of 4754 men were diagnosed with prostate cancer, and 713 men satisfied with inclusion criteria; 433 (60.7 %) and 280 (39.3 %) chose AS and IT, respectively. A total of 87 urologists were included. Univariate and multivariate adjusted analyses revealed no differences in urologist's age or years in practice. Patients who saw urologists who had performed ≥50 robotic surgeries were less likely to choose AS (OR 0.40, 95 % CI 0.25-0.66). Patients who saw urologists with a fellowship in oncology and/or robotics were more than twice as likely to choose AS (OR 2.27, 95 % CI 1.38-3.75).

CONCLUSION

These data suggest that the decision to pursue AS may be influenced by the urologist's experience.

Magnetic Resonance Imaging Targeted Biopsy Improves Selection of Patients Considered for Active Surveillance for Clinically Low Risk Prostate Cancer Based on Systematic Biopsies

PURPOSE

Current selection criteria for active surveillance based on systematic biopsy underestimate prostate cancer volume and grade. We investigated the role of additional magnetic resonance imaging targeted biopsy in reclassifying patients eligible for active surveillance based on systematic biopsy.

MATERIALS AND METHODS

We performed a study at 2 institutions in a total of 281 men with increased prostate specific antigen. All men met certain criteria, including 1) prebiopsy magnetic resonance imaging, 12-core transrectal systematic biopsy and 2 additional magnetic resonance imaging targeted biopsies of lesions suspicious for cancer during the same sequence as systematic biopsy, and 2) eligibility for active surveillance based on systematic biopsy results. Criteria for active surveillance were prostate specific antigen less than 10 ng/ml, no Gleason grade 4/5, 5 mm or less involvement of any biopsy core and 2 or fewer positive systematic biopsy cores. Patient characteristics were compared between reclassified and nonreclassified groups based on magnetic resonance imaging targeted biopsy results.

RESULTS

On magnetic resonance imaging 58% of the 281 patients had suspicious lesions. Magnetic resonance imaging targeted biopsy was positive for cancer in 81 of 163 patients (50%). Of 281 patients 28 (10%) were reclassified by magnetic resonance imaging targeted biopsy as ineligible for active surveillance based on Gleason score in 8, cancer length in 20 and Gleason score plus cancer length in 9. Suspicious areas on magnetic resonance imaging were in the anterior part of the prostate in 15 of the 28 men (54%). Reclassified patients had a smaller prostate volume (37 vs 52 cc) and were older (66.5 vs 63 years) than those who were not reclassified (p < 0.05).

CONCLUSIONS

Magnetic resonance imaging targeted biopsy reclassified 10% of patients who were eligible for active surveillance based on systematic biopsy. Its incorporation into the active surveillance eligibility criteria may decrease the risk of reclassification to higher stages during followup.

Insignificant disease among men with intermediate-risk prostate cancer

PURPOSE

A paucity of data exists on the insignificant disease potentially suitable for active surveillance (AS) among men with intermediate-risk prostate cancer (PCa). We tried to identify pathologically insignificant disease and its preoperative predictors in men who underwent radical prostatectomy (RP) for intermediate-risk PCa.

METHODS

We analyzed data of 1,630 men who underwent RP for intermediate-risk disease. Total tumor volume (TTV) data were available in 332 men. We examined factors associated with classically defined pathologically insignificant cancer (organ-confined disease with TTV ≤0.5 ml with no Gleason pattern 4 or 5) and pathologically favorable cancer (organ-confined disease with no Gleason pattern 4 or 5) potentially suitable for AS. Decision curve analysis was used to assess clinical utility of a multivariable model including preoperative variables for predicting pathologically unfavorable cancer.

RESULTS

In the entire cohort, 221 of 1,630 (13.6 %) total patients had pathologically favorable cancer. Among 332 patients with TTV data available, 26 (7.8 %) had classically defined pathologically insignificant cancer. Between threshold probabilities of 20 and 40 %, decision curve analysis demonstrated that using multivariable model to identify AS candidates would not provide any benefit over simply treating all men who have intermediate-risk disease with RP.

CONCLUSION

Although a minority of patients with intermediate-risk disease may harbor pathologically favorable or insignificant cancer, currently available conventional tools are not sufficiently able to identify those patients.

Predictive factors of unfavorable prostate cancer in patients who underwent prostatectomy but eligible for active surveillance

PURPOSE

To investigate the predictive factors of unfavorable prostate cancer in Korean men who underwent radical prostatectomy but eligible for active surveillance according to Epstein criteria.

METHODS

We retrospectively reviewed the medical records of 2,036 patients who underwent radical prostatectomy for prostate cancer between 1994 and 2011. Among these, 233 patients were eligible for active surveillance based on Epstein criteria. Unfavorable prostate cancer was defined as pathologic Gleason sum ≥7 or non-organ-confined disease. We investigated pathologic outcomes and predictive factors for unfavorable prostate cancer.

RESULTS

Of 233 cases, 91 patients (39.1%) were pathologic Gleason sum ≥7, 11 (4.7%) had extracapsular extension, and three (1.3%) had seminal vesicle invasion. Ninety-eight patients (42.1%) had unfavorable prostate cancer. When comparing clinically insignificant and significant prostate cancer, there were significant differences in mean age (P=0.007), prostate volume (P=0.021), prostate-specific antigen (PSA) density (P=0.03), maximum tumor volume in biopsy core (P<0.001), and rate of two positive cores (P=0.001). On multivariate analysis, age (P=0.015), PSA density (P=0.017) and two positive cores (P=0.001) were independent predictive factors for unfavorable prostate cancer.

CONCLUSIONS

A significant proportion of patients who were candidates for active surveillance had unfavorable prostate cancer. Age, PSA density, and two positive cores were independent significant predictive factors for unfavorable prostate cancer. These factors should be considered when performing active surveillance.

Methylation markers for prostate cancer prognosis: a systematic review

PURPOSE

We conducted a systematic review to summarize current evidence on the prognostic utility of DNA methylation markers in prostate cancer and ascertain knowledge gaps to inform future research.

METHODS

We identified relevant studies using combined key search against PubMed database. Inclusion criteria were studies of human subjects that examined the association between DNA methylation markers and prostate cancer disease outcomes. The methodological quality of each study was systematically evaluated. Findings were qualitatively summarized. Due to heterogeneity and concerns of internal validity, no meta-analysis was performed.

RESULTS

Twenty studies were reviewed; sample size ranged from 35 to 605 men in the prognostic analyses. Sixteen studies examined methylation markers in prostate cancer tissue and four examined circulating DNA methylation markers. Of all genes reviewed, paired-like homeodomain transcription factor 2 (PITX2) methylation was examined in two more rigorously designed studies and was found to be associated with biochemical recurrence. Common limitations in current literature included small sample sizes,lack of adequate adjustment for established prognostic factors, and poor reporting quality.

CONCLUSION

Evidence on the prognostic utility of methylation markers in prostate cancer is inconclusive. Future research should ascertain large samples with adequate follow-up and include patients of racial/ethnic minority and those treated with modalities other than prostatectomy(e.g., using prostate cancer diagnostic biopsy as tissue source).

Targeted prostate biopsy in select men for active surveillance: do the Epstein criteria still apply?

PURPOSE

Established in 1994, the Epstein histological criteria (Gleason score 6 or less, 2 or fewer cores positive and 50% or less of any core) have been widely used to select men for active surveillance. However, with the advent of targeted biopsy, which may be more accurate than conventional biopsy, we reevaluated the likelihood of reclassification upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion.

MATERIALS AND METHODS

We identified 113 men enrolled in active surveillance at our institution who met Epstein criteria and subsequently underwent confirmatory targeted biopsy via multiparametric magnetic resonance imaging-ultrasound fusion. Median patient age was 64 years, median prostate specific antigen was 4.2 ng/ml and median prostate volume was 46.8 cc. Targets or regions of interest on multiparametric magnetic resonance imaging-ultrasound fusion were graded by suspicion level and biopsied at 3 mm intervals along the longest axis (median 10.5 mm). Also, 12 systematic cores were obtained during confirmatory rebiopsy. Our reporting is consistent with START (Standards of Reporting for MRI-targeted Biopsy Studies) criteria.

RESULTS

Confirmatory fusion biopsy resulted in reclassification in 41 men (36%), including 26 (23%) due to Gleason grade 6 or greater and 15 (13%) due to high volume Gleason 6 disease. When stratified by suspicion on multiparametric magnetic resonance imaging-ultrasound fusion, the likelihood of reclassification was 24% to 29% for target grade 0 to 3, 45% for grade 4 and 100% for grade 5 (p=0.001). Men with grade 4 and 5 vs lower grade targets were greater than 3 times more likely to be reclassified (OR 3.2, 95% CI 1.4-7.1, p=0.006).

CONCLUSIONS

Upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion men with high suspicion targets on imaging were reclassified 45% to 100% of the time. Criteria for active surveillance should be reevaluated when multiparametric magnetic resonance imaging-ultrasound fusion guided prostate biopsy is used.

Revised Gleason grading system is a better predictor of indolent prostate cancer at the time of diagnosis: retrospective clinical-pathological study on matched biopsy and radical prostatectomy specimens

INTRODUCTION/BACKGROUND

The increase of prostate cancer diagnosis after the introduction of prostate-specific antigen (PSA) screening resulted in overtreatment of patients with low risk tumors. The histological Gleason score (GS) revised in 2005 by the International Society of Urological Pathology (ISUP) is currently the most reliable tool to separate aggressive from indolent prostate cancer.

MATERIALS AND METHODS

Using the new 2005 GS criteria we retrospectively evaluated biopsy and surgical samples of 1344 patients who underwent radical prostatectomy in our institution. According to the new GS criteria we then selected 134 patients who would have been suitable for active surveillance at the time of biopsy (at least 2 positive cores, PSA < 10 ng/mL, GS ≤ 6). We finally assessed the accuracy of the revised GS in biopsy to predict indolent cancer in the prostatectomy specimens.

RESULTS

The mean GS increased from 6 to 7 after histological revision in biopsy and prostatectomy specimens. Histological revision determined a significant decrease of patients with GS ≤ 6 and an increase of those with GS ≥ 7 (all P < .001). The average of pathologically indolent disease (organ-confined, GS ≤ 6 at surgery, tumor of any volume) significantly decreased after histological revision (P < .001).

CONCLUSION

The revised ISUP 2005 criteria for Gleason grading provided better stratification of GS ≤ 6 prostate cancer and improved the accuracy for the histological diagnosis of indolent prostate cancer in biopsy and radical prostatectomy specimens.

Prostate cancer and the increasing role of active surveillance

Prostate cancer (PC) is the most often diagnosed non-skin cancer and the second leading cause of cancer-related death among men in the United States. As a result, for many years the American Urological Association (AUA) and the American Cancer Society have issued statements recommending screening for PC, resulting in its widespread implementation in the United States. Recently, the United States Preventative Services Task Force gave PC screening a recommendation of D, that is, against PC screening for all men. The AUA countered this recommendation, stating that since the development of PC screening using prostate-specific antigen, a reduction in PC-specific mortality has been seen, and that the risk reduction occurred in a setting in which many of the patients were not aggressively treated for prostate cancer. Active surveillance may be described as a method to potentially delay or obviate the need for treatment in men with clinically insignificant PC or PC thought to be at low risk for progression. Studies have shown no significant difference in outcome or pathology between men with low risk PC who receive treatment at the point of progression and those undergoing immediate treatment. Ongoing studies are evaluating the efficacy and utility of active surveillance for low-risk PC. Interim results of these studies have shown that approximately 30% of patients progress on active surveillance. However, "progression" does not necessarily mean treatment failure; rarely do patients develop locally advanced or metastatic disease. Active surveillance has also been shown to be cost-effective when compared with immediate treatment for PC. Longer follow-up may continue to show an increased benefit of active surveillance as a reasonable initial approach to the management of men with low-risk, clinically localized PC.

Active surveillance for prostate cancer: an underutilized opportunity for reducing harm

The management of localized prostate cancer is controversial, and in the absence of comparative trials to inform best practice, choices are driven by personal beliefs with wide variation in practice patterns. Men with localized disease diagnosed today often undergo treatments that will not improve overall health outcomes, and active surveillance has emerged as one approach to reducing this overtreatment of prostate cancer. The selection of appropriate candidates for active surveillance should balance the risk of harm from prostate cancer without treatment, and a patient's personal preferences for living with a cancer and the potential side effects of curative treatments. Although limitations exist in assessing the potential for a given prostate cancer to cause harm, the most common metrics used today consider cancer stage, prostate biopsy features, and prostate-specific antigen level together with the risk of death from nonprostate causes based on age and overall state of health.

Transperineal template-guided mapping biopsy as a staging procedure to select patients best suited for active surveillance

OBJECTIVES

Patients with clinically insignificant prostate cancer are candidates for active surveillance. However, uncertainty regarding the true extent of disease limits enthusiasm. In this study, we report our initial findings in patients with transrectal ultrasound (TRUS)-detected clinically insignificant prostate cancer undergoing transperineal template-guided mapping biopsy (TTMB) as a staging procedure.

METHODS

Sixty-four patients who met the Epstein criteria for clinically insignificant prostate cancer underwent TTMB. Each biopsy core position was recorded in 3 dimensions with documentation of location of each positive biopsy core, Gleason score, percentage of involvement of each core, and presence/absence of perineural invasion.

RESULTS

Mean pre-TRUS prostate specific antigen was 4.7 ng/mL with a Gleason score of 6 involving a median of 5% of 1 TRUS core. The mean number of TTMB biopsy cores was 58.5, with 6.6 cores positive for malignancy. Ten patients had clinically insignificant prostate cancer (15.7%), 8 had no TTMB-detected cancer (12.5%), and 46 (71.9%) had clinically significant cancer. Of patients with cancer, 37 (66.1%) had bilobar involvement and 25 (44.6%) harbored a Gleason score of ≥7. In a multivariate analysis, tobacco consumption was found to be most closely related to clinically significant disease on TTMB.

CONCLUSIONS

TRUS biopsy underestimates disease extent and Gleason score in some patients. TTMB provides a more accurate assessment of the presence of aggressive histology.

Prostate cancer: can multiparametric MR imaging help identify patients who are candidates for active surveillance?

PURPOSE

To determine whether multiparametric magnetic resonance (MR) imaging can help identify patients with prostate cancer who would most appropriately be candidates for active surveillance (AS) according to current guidelines and to compare the results with those of conventional clinical assessment scoring systems, including the D'Amico, Epstein, and Cancer of the Prostate Risk Assessment (CAPRA) systems, on the basis of findings at prostatectomy.

MATERIALS AND METHODS

This institutional review board-approved HIPAA-compliant retrospectively designed study included 133 patients (mean age, 59.3 years) with a mean prostate-specific antigen level of 6.73 ng/mL (median, 4.39 ng/mL) who underwent multiparametric MR imaging at 3.0 T before radical prostatectomy. Informed consent was obtained from all patients. Patients were then retrospectively classified as to whether they would have met AS eligibility criteria or were better served by surgery. AS eligibility criteria for prostatectomy specimens were a dominant tumor smaller than 0.5 mL without Gleason 4 or 5 patterns or extracapsular or seminal vesicle invasion. Conventional clinical assessment scores (the D'Amico, Epstein, and CAPRA scoring systems) were compared with multiparametric MR imaging findings for predicting AS candidates. The level of significance of difference between scoring systems was determined by using the χ(2) test for categoric variables with the level of significance set at P < .05.

RESULTS

Among 133 patients, 14 were eligible for AS on the basis of prostatectomy results. The sensitivity, positive predictive value (PPV), and overall accuracy, respectively, were 93%, 25%, and 70% for the D'Amico system, 64%, 45%, and 88% for the Epstein criteria, and 93%, 20%, and 59% for the CAPRA scoring system for predicting AS candidates (P < .005 for all, χ(2) test), while multiparametric MR imaging had a sensitivity of 93%, a PPV of 57%, and an overall accuracy of 92% (P < .005).

CONCLUSION

Multiparametric MR imaging provides useful additional information to existing clinicopathologic scoring systems of prostate cancer and improves the assignment of treatment (eg, AS or active treatment).

Risk of Gleason grade inaccuracies in prostate cancer patients eligible for active surveillance

OBJECTIVE

To evaluate increases in Gleason grade because of sample bias after immediate rebiopsy or prostatectomy for patients considered active surveillance candidates by institutional protocol.

METHODS

A contemporary medical literature search was performed using PubMed. Series were included if the patients had no more than Gleason 6 prostate cancer score on initial biopsy and underwent a prostatectomy or rebiopsy within 6 months. Patient sets using neoadjuvant hormonal therapy or focal prostate treatment were excluded.

RESULTS

In patients who would have fallen into the D'Amico low-risk prostate cancer group, 42% were found to have an increase in the Gleason score: 32% resulting in grade ≥ 7 disease and 3% grade ≥ 8. For series that limited patients to the Epstein criteria, Gleason upgrades were 34%, 29%, and 2%, respectively. Of the 139 patients whose second tissue specimens were from a rebiopsy, 17% were found to have grade ≥ 7 disease, whereas only 1 patient had grade ≥ 8. There were no consistent multivariate analysis variables among the series to predict for an increase in Gleason score.

CONCLUSION

More than one third of the patients were found to have been undergraded based on their initial prostate biopsy. Therefore, 1 biopsy alone may not be sufficient to offer active surveillance as an option. Further exploration is necessary to better ensure low-risk disease before active surveillance.

Correlation of magnetic resonance imaging tumor volume with histopathology

PURPOSE

The biology of prostate cancer may be influenced by the index lesion. The definition of index lesion volume is important for appropriate decision making, especially for image guided focal treatment. We determined the accuracy of magnetic resonance imaging for determining index tumor volume compared with volumes derived from histopathology.

MATERIALS AND METHODS

We evaluated 135 patients (mean age 59.3 years) with a mean prostate specific antigen of 6.74 ng/dl who underwent multiparametric 3T endorectal coil magnetic resonance imaging of the prostate and subsequent radical prostatectomy. Index tumor volume was determined prospectively and independently by magnetic resonance imaging and histopathology. The ellipsoid formula was applied to determine histopathology tumor volume, whereas manual tumor segmentation was used to determine magnetic resonance tumor volume. Histopathology tumor volume was correlated with age and prostate specific antigen whereas magnetic resonance tumor volume involved Pearson correlation and linear regression methods. In addition, the predictive power of magnetic resonance tumor volume, prostate specific antigen and age for estimating histopathology tumor volume (greater than 0.5 cm(3)) was assessed by ROC analysis. The same analysis was also conducted for the 1.15 shrinkage factor corrected histopathology data set.

RESULTS

There was a positive correlation between histopathology tumor volume and magnetic resonance tumor volume (Pearson coefficient 0.633, p <0.0001), but a weak correlation between prostate specific antigen and histopathology tumor volume (Pearson coefficient 0.237, p = 0.003). On linear regression analysis histopathology tumor volume and magnetic resonance tumor volume were correlated (r(2) = 0.401, p <0.00001). On ROC analysis AUC values for magnetic resonance tumor volume, prostate specific antigen and age in estimating tumors larger than 0.5 cm(3) at histopathology were 0.949 (p <0.0000001), 0.685 (p = 0.001) and 0.627 (p = 0.02), respectively. Similar results were found in the analysis with shrinkage factor corrected tumor volumes at histopathology.

CONCLUSIONS

Magnetic resonance imaging can accurately estimate index tumor volume as determined by histology. Magnetic resonance imaging has better accuracy in predicting histopathology tumor volume in tumors larger than 0.5 cm(3) than prostate specific antigen and age. Index tumor volume as determined by magnetic resonance imaging may be helpful in planning treatment, specifically in identifying tumor margins for image guided focal therapy and possibly selecting better active surveillance candidates.

Extended biopsy based criteria incorporating cumulative cancer length for predicting clinically insignificant prostate cancer

What's known on the subject? and What does the study add? The criteria used for selecting patients with prostate cancer for active surveillance (AS) are still not satisfactory due to the difficulty in predicting the significance of the prostate cancer. Urologists could predict insignificant prostate cancer by incorporating cumulative cancer length and biopsy Gleason score, derived from extended biopsy. The present study has added new criteria for predicting insignificant prostate cancer, which would lead to a better selection of candidates for AS.

OBJECTIVE

• To develop extended biopsy based criteria for predicting insignificant cancer (IC) using extended biopsy findings.

PATIENTS AND METHODS

• From 2000 to 2009, 1575 patients with prostate cancer were primarily treated by radical prostatectomy in two referral hospitals. • Of these, the study cohort comprised 499 patients with extended biopsy confirmed, clinically organ-confined (cT1-2N0M0) prostate cancer with PSA levels of <20 ng/mL. • Cancer information obtained through extended biopsy included cumulative cancer length (CCL) divided by the number of biopsy cores (CCL/core).

RESULTS

• Pathological examination revealed 39 ICs (7.8%). All these ICs fell in a category of prostate cancer with clinical stage ≤ T2a and 2005 International Society of Urological Pathology Consensus Conference (ISUP) modified biopsy Gleason score ≤ 7. • Accordingly, we analysed predictors of IC in a subset cohort of 370 patients in this category. A multivariate logistic regression analysis revealed that 2005 ISUP modified biopsy Gleason score and CCL/core were independently significant predictors of IC. • We determined a threshold value of CCL/core of 0.20 mm for predicting IC using receiver operating characteristic analysis. • Based on these findings, we developed simple extended biopsy based criteria for predicting IC as follows: (i) PSA level of <20 ng/mL; (ii) Clinical stage ≤ T2a; (iii) 2005 ISUP modified biopsy Gleason score ≤ 6; (iv) CCL/core of <0.20 mm. • The specificity of the criteria was 91%, which was significantly higher than the value from a subset of criteria without item iv (P < 0.001).

CONCLUSION

• We have developed extended biopsy based criteria for predicting IC incorporating the 2005 ISUP modified biopsy Gleason score and CCL/core.

Active surveillance for prostate cancer: past, present and future

PURPOSE OF REVIEW

This article reviews recent developments in the use of active surveillance for localized prostate cancer.

RECENT FINDINGS

The treatment of localized prostate cancer continues to be a major challenge for urologic oncologists. Screening with prostate-specific antigen has resulted in increased numbers of low-risk prostate cancers being detected. Aggressive whole-gland therapy with surgery, or radiation therapy is associated with potentially life-altering treatment-related side effects such as urinary incontinence, bowel toxicity and erectile dysfunction. The goal of active surveillance is to avoid or delay the adverse events associated with prostate cancer therapy while still allowing for curative intervention in the future, if needed.

SUMMARY

Active surveillance is a reasonable treatment option for many men with low-risk, and some men with intermediate-risk, prostate cancer. Additional research is needed to determine the optimal active surveillance inclusion criteria, monitoring schedule, and treatment triggers. It is hoped that advances in prostate imaging, biomarkers, and focal therapy will foster greater use of active surveillance in appropriately selected men to optimize quality-of-life without compromising cancer outcomes.

Active surveillance as a practical strategy to differentiate lethal and non-lethal prostate cancer subtypes

Differentiation between lethal and non-lethal prostate cancer subtypes has become a very important issue in avoiding excessive treatment in an era when prostate-specific antigen (PSA) screening has reduced the rate of prostate cancer deaths by more than 20%. However, it is difficult to determine the patients who may or may not benefit from immediate treatment interventions at the time of the initial diagnosis. The selection of candidate patients who can postpone immediate treatment and undergo follow-ups with a specific surveillance program, or 'active surveillance,' is a practical way to minimize overtreatment. In this review, the benefits and risks of active surveillance are discussed. Future perspectives, including imaging and new biomarkers for improving the outcomes of active surveillance programs, are also discussed.

Formalized prediction of clinically significant prostate cancer: is it possible?

Greater understanding of the biology and epidemiology of prostate cancer in the last several decades have led to significant advances in its management. Prostate cancer is now detected in greater numbers at lower stages of disease and is amenable to multiple forms of efficacious treatment. However, there is a lack of conclusive data demonstrating a definitive mortality benefit from this earlier diagnosis and treatment of prostate cancer. It is likely due to the treatment of a large proportion of indolent cancers that would have had little adverse impact on health or lifespan if left alone. Due to this overtreatment phenomenon, active surveillance with delayed intervention is gaining traction as a viable management approach in contemporary practice. The ability to distinguish clinically insignificant cancers from those with a high risk of progression and/or lethality is critical to the appropriate selection of patients for surveillance protocols versus immediate intervention. This chapter will review the ability of various prediction models, including risk groupings and nomograms, to predict indolent disease and determine their role in the contemporary management of clinically localized prostate cancer.

Biomarker research in prostate cancer--towards utility, not futility

The identification of an appropriate clinical question is critical for any biomarker project. Despite rapid advances in technology, few biomarkers have been forthcoming for prostate cancer. This could be because the clinical questions under investigation have not actually originated from clinical practice. These clinical questions are difficult to identify in the complex and heterogeneous pathogenesis of prostate cancer. In this Review, we have developed a prostate cancer 'roadmap' to identify the aspects of prostate cancer that may be amenable to biomarker discovery and serve as a guide for future projects in prostate cancer biomarker research.