Expanded criteria to identify men eligible for active surveillance of low risk prostate cancer at Johns Hopkins: a preliminary analysis

Update and optimization of active surveillance in prostate cancer in 2021

INTRODUCTION AND OBJECTIVES

Within the paradigm shift of the last decade in the management of prostate cancer (PCa), perhaps the most relevant event has been the emergence of active surveillance (AS) as a mandatory strategy in low-risk disease. We carry out a critical review of the clinical, pathological and radiological improvements that allow optimizing AS in 2021.

MATERIAL AND METHODS

Critical narrative review of the literature on improvement issues and controversial aspects of AS.

RESULTS

Adequate use of traditional criteria, optimized by enhanced biopsy and calculation of the prostate volume technique thanks to multiparametric magnetic resonance imaging (mpMRI) allow a better selection of patients for AS. This management should not be limited to patients under 60years of age, and patients with intermediate-risk PCa should be carefully selected to be included. Biopsies are still required in the follow-up, which can be personalized according to risk patterns. The pathologist must identify the cribriform or intraductal histology on biopsies in order to exclude these patients from AS, in the same way as with patients with alterations in DNA repair genes.

CONCLUSIONS

Controversial indications such as the inclusion of patients from intermediate-risk groups, or the transition to active treatment due to exclusive progression in tumor volume, should be further optimized. It is possible that the future competition of tissue biomarkers, the refinement of objective parameters of mpMRI and the validation of PSA kinetics calculators may sub-stratify risk groups.

Expanded criteria for active surveillance in prostate cancer: a review of the current data

Over the last ten years, active surveillance (AS) has become increasingly utilized for patients with low-risk prostate cancer. Appropriately selected AS patients have a 10-year prostate cancer-specific mortality (PCSM) approaching 99%. Therefore, some institutions have expanded the inclusion criteria for AS to avoid the unnecessary morbidity associated with overtreatment. In this review, data from several high-quality studies were compiled to demonstrate how AS inclusion criteria may be safely expanded. Although AS criteria, data reporting, and statistical methods were heterogeneous across studies, several findings were consistent and provided insight for clinical practice. Gleason score ≥3+4 and prostate specific antigen density (PSAd) ≥0.15 ng/mL were consistently associated poor oncologic outcomes [biopsy reclassification/progression, adverse pathology at prostatectomy, biochemical recurrence (BCR), and PCSM]. Maximum single-core involvement, number of positive cores, and clinical stage were not consistently associated with negative outcomes. These data support the safety of expanded AS inclusion criteria beyond Epstein’s very low-risk (VLR) criteria to include patients with clinical stage T2, up to 60% maximum core involvement, and up to 4 positive cores (Gleason 3+3 and ≤ PSAd 0.15 ng/mL). Furthermore, although it is clear that patients with intermediate-risk disease have poorer oncologic outcomes compared to low-risk, the absolute 10-year PCSM remains low and select patients may be optimally managed with AS. Although AS utilization is increasing, many men who might be safely managed with AS are still undergoing morbid and unnecessary definitive treatments. Further research into clinical parameters such as multiparametric magnetic resonance imaging (mpMRI) and genetic testing is required to improve the accuracy of patient stratification.

3+4 = 6? Implications of the stratification of localised Gleason 7 prostate cancer by number and percentage of positive biopsy cores in selecting patients for active surveillance

OBJECTIVE

To determine whether the number and percentage of positive biopsy cores identify a Gleason 3+4 prostate cancer (PC) subgroup of similar biologic behaviour to Gleason 3+3.

MATERIAL AND METHOD

An observational post-radical prostatectomy study was conducted of a cohort of 799 patients with localised low-risk (n=582, Gleason 6, PSA <10ng/ml and cT1c-2a) and favourable intermediate PC (n=217, Gleason 3+4, PSA ≤10 ng/ml and pT2abc). The Gleason 3+4 tumours were stratified by number (≤3 vs.>3) and by percentage of positive cores (≤33% vs. >33%). We analysed the tumours' association with the biochemical recurrence risk (BRR) and cancer-specific mortality (CSM). We conducted various predictive models using Cox regression and estimated (C-index) and compared their predictive capacity.

RESULTS

With a median follow-up of 71 months, the BRR and CSM of the patient group with Gleason 3+4 tumours and a low number (≤3) and percentage (≤33%) of positive cores were not significantly different from those of the patients with Gleason 6 tumours. At 5 and 10 years, there were no significant differences in the number of biochemical recurrences, the probability of remaining free of biochemical recurrences, the number of deaths by PC or the probability of death by PC between the 2 groups. In contrast, the patients with Gleason 3+4 tumours and more than 33% of positive cores presented more deaths by PC than the patients with Gleason 6 tumours. At 10 years, the probability of CSM was significantly greater. This subgroup of tumours showed a significantly greater BRR (RR, 1.6; P=.02) and CSM (RR, 5.8, P≤.01) compared with the Gleason 6 tumours. The model with Gleason 3+4 stratified by the percentage of positive cores significantly improved the predictive capacity of BRR and CSM.

CONCLUSIONS

Fewer than 3 cores and a percentage <33% of positive cores identifies a subgroup of Gleason 3+4 tumours with biological behaviour similar to Gleason 6 tumours. At 10 years, there were no differences in BRR and CSM between the 2 groups. These results provide evidence supporting active surveillance as an alternative for Gleason 3+4 tumours and low tumour extension in biopsy.

Biomarkers in active surveillance

The use of active surveillance (AS) is increasing for favorable-risk prostate cancer. However, there remain challenges in patient selection for AS, due to the limitations of current clinical staging. In addition, monitoring protocols relying on serial biopsies is invasive and presents risks such as infection. For these reasons, there is substantial interest in identifying markers that can be used to improve AS selection and monitoring. In this article, we review the evidence on serum, urine and tissue markers in AS.

Variability in Outcomes for Patients with Intermediate-risk Prostate Cancer (Gleason Score 7, International Society of Urological Pathology Gleason Group 2-3) and Implications for Risk Stratification: A Systematic Review

CONTEXT

Optimal management for patients with intermediate-risk (IR) prostate cancer (PCa) remains controversial. Clinical metrics provide guidance on appropriate management options.

OBJECTIVE

To report estimates for clinically relevant outcomes in men with IR PCa based on clinical and pathological features.

EVIDENCE ACQUISITION

PubMed and programs from key 2015 uro-oncology congresses were searched using the terms "intermediate", "Gleason 3 + 4", "Gleason 4 + 3", "active surveillance", "treatment", "adverse pathology", AND "prostate cancer." Articles meeting prespecified criteria were retrieved. Bibliographies were scanned for additional relevant references.

EVIDENCE SYNTHESIS

Men with IR PCa have a wide range of predicted clinically relevant outcomes. Within the IR category, estimate ranges for adverse surgical pathology and 5-yr disease progression are 15-64% and 21-91%, respectively. Clinical parameters and predictive nomograms refine these estimates, but do not uniformly differentiate favorable and unfavorable IR PCa. Variations in study design and data quality in source manuscripts mandate caution in interpreting results.

CONCLUSIONS

Outcomes in IR PCa are heterogeneous. Refinements in personalized risk assessment are needed to better select IR PCa patients for surveillance.

PATIENT SUMMARY

Current and future risk stratification tools may provide additional information to identify men with intermediate-risk prostate cancer who may consider active surveillance.

The influence of prostate-specific antigen density on positive and negative predictive values of multiparametric magnetic resonance imaging to detect Gleason score 7-10 prostate cancer in a repeat biopsy setting

OBJECTIVES

To evaluate the influence of prostate-specific antigen density (PSAD) on positive (PPV) and negative (NPV) predictive values of multiparametric magnetic resonance imaging (mpMRI) to detect Gleason score ≥7 cancer in a repeat biopsy setting.

PATIENTS AND METHODS

Retrospective study of 514 men with previous prostate biopsy showing no or Gleason score 6 cancer. All had mpMRI, graded 1-5 on a Likert scale for cancer suspicion, and subsequent targeted and 24-core systematic image-fusion guided transperineal biopsy in 2013-2015. The NPVs and PPVs of mpMRIs for detecting Gleason score ≥7 cancer were calculated (±95% confidence intervals) for PSAD ≤0.1, 0.1-0.2, ≤0.2 and >0.2 ng/mL/mL, and compared by chi-square test for linear trend.

RESULTS

Gleason score ≥7 cancer was detected in 31% of the men. The NPV of Likert 1-2 mpMRI was 0.91 (±0.04) with a PSAD of ≤0.2 ng/mL/mL and 0.71 (±0.16) with a PSAD of >0.2 ng/mL/mL (P = 0.003). For Likert 3 mpMRI, PPV was 0.09 (±0.06) with a PSAD of ≤0.2 ng/mL/mL and 0.44 (±0.19) with a PSAD of >0.2 ng/mL/mL (P = 0.002). PSAD also significantly affected the PPV of Likert 4-5 mpMRI lesions: the PPV was 0.47 (±0.08) with a PSAD of ≤0.2 ng/mL/mL and 0.66 (±0.10) with a PSAD of >0.2 ng/mL/mL (P < 0.001).

CONCLUSION

In a repeat biopsy setting, a PSAD of ≤0.2 ng/mL/mL is associated with low detection of Gleason score ≥7 prostate cancer, not only in men with negative mpMRI, but also in men with equivocal imaging. Surveillance, rather than repeat biopsy, may be appropriate for these men. Conversely, biopsies are indicated in men with a high PSAD, even if an mpMRI shows no suspicious lesion, and in men with an mpMRI suspicious for cancer, even if the PSAD is low.

Selection Criteria for Active Surveillance of Patients with Prostate Cancer in Korea: A Multicenter Analysis of Pathology after Radical Prostatectomy

Purpose

Korean patients with prostate cancer (PC) typically present with a more aggressive disease than patients in Western populations. Consequently, it is unclear if the current criteria for active surveillance (AS) can safely be applied to Korean patients. Therefore, this study was conducted to define appropriate selection criteria for AS for patients with PC in Korea.

Materials and Methods

We conducted a multicenter retrospective study of 2,126 patients with low risk PC who actually underwent radical prostatectomy. The primary outcome was an unfavorable disease, which was defined by non-organ confined disease or an upgrading of the Gleason score to ≥ 7 (4+3). Predictive variables of an unfavorable outcome were identified by multivariate analysis using randomly selected training samples (n=1,623, 76.3%). We compared our selected criteria to various Western criteria for the primary outcome and validated our criteria using the remaining validation sample (n=503, 23.7%).

Results

A non-organ confined disease rate of 14.9% was identified, with an increase in Gleason score ≥ 7 (4+3) of 8.7% and a final unfavorable disease status of 20.8%. The following criteria were selected: Gleason score ≤ 6, clinical stage T1-T2a, prostate-specific antigen (PSA) ≤ 10 ng/mL, PSA density < 0.15 ng/mL/mL, number of positive cores ≤ 2, and maximum cancer involvement in any one core ≤ 20%. These criteria provided the lowest unfavorable disease rate (11.7%) when compared to Western criteria (13.3%-20.7%), and their validity was confirmed using the validation sample (5.9%).

Conclusion

We developed AS criteria which are appropriate for Korean patients with PC. Prospective studies using these criteria are now warranted.

Targeted Biopsy to Detect Gleason Score Upgrading during Active Surveillance for Men with Low versus Intermediate Risk Prostate Cancer

PURPOSE

We sought to determine the rate of upgrading to Gleason score 4 + 3 or greater using targeted biopsy for diagnosis and monitoring in men undergoing active surveillance of prostate cancer.

MATERIALS AND METHODS

Study subjects comprised all 259 men, including 196 with Gleason score 3 + 3 and 63 with Gleason score 3 + 4, who were diagnosed by magnetic resonance imaging/ultrasound fusion guided biopsy from 2009 to 2015 and underwent subsequent fusion biopsy for as long as 4 years of active surveillance. The primary end point was the discovery of Gleason score 4 + 3 or greater prostate cancer. Followup biopsies included targeting of positive sites, which were tracked in an Artemis™ device. Kaplan-Meier curves were generated to determine upgrading rates, stratified by initial Gleason score and prostate specific antigen density.

RESULTS

Based on a Cox proportional hazard model, men with Gleason score 3 + 4 were 4.65 times more likely to have upgrading than men with an initial Gleason score of 3 + 3 at 3 years (p <0.01). By the third surveillance year 63% of men with Gleason score 3 + 4 had been upgraded compared with 18.0% who started with Gleason score 3 + 3 (p <0.01). Of all 33 upgrades 32 (97%) occurred at a magnetic resonance imaging visible or a tracked site of tumor, rather than at a previously negative systematic site. Independent predictors of upgrading were Gleason score 3 + 4, prostate specific antigen density 0.15 ng/ml/cm3 or greater and a grade 5 lesion on magnetic resonance imaging. The incidence rate ratio of upgrading (Gleason score 3 + 4 vs 3 + 3) was 4.25 per year of patient followup (p <0.01).

CONCLUSIONS

During active surveillance of prostate cancer, targeting of tracked tumor foci by magnetic resonance imaging/ultrasound fusion biopsy allows for heightened detection of Gleason score 4 + 3 or greater cancers. Baseline variables directly related to important upgrading that warrant increased vigilance include Gleason score 3 + 4, prostate specific antigen density 0.15 ng/ml/cm3 or greater and grade 5 lesions on magnetic resonance imaging.

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.

Biopsy Perineural Invasion in Prostate Cancer Patients Who Are Candidates for Active Surveillance by Strict and Expanded Criteria

OBJECTIVE

To evaluate the association of biopsy perineural invasion (PNI) with adverse pathologic findings on radical prostatectomy in patients who would have been candidates for active surveillance (AS).

METHODS

Using a prospectively populated database of 3084 men who underwent open radical prostatectomy, candidates for AS by strict (Johns Hopkins) and expanded (University of Toronto) criteria were identified. The presence of adverse pathologic features at radical prostatectomy was compared between those men with and without biopsy PNI.

RESULTS

Of 596 men who met strict criteria for AS, 16 (3%) had biopsy PNI. In the strict AS cohort, there were no differences in adverse pathologic features at radical prostatectomy between those with and without PNI. Of 1197 men who were candidates for AS by expanded criteria, 102 (9%) had biopsy PNI. Men with biopsy PNI in the expanded AS cohort were more likely to have extraprostatic extension (P < .001) and pathologic upgrading (P = .01) at prostatectomy. In addition, those with PNI had larger dominant nodules (P < .001), and cancer comprised a greater percentage of their prostate glands (P < .001). There was no difference in the proportion with a positive margin between the 2 groups (P = .77).

CONCLUSION

Biopsy PNI was rare in patients who met strict criteria for AS. Among those men who met expanded criteria, PNI was associated with adverse pathologic findings upon prostatectomy. The presence of biopsy PNI may have a role in further risk stratifying patients who meet expanded criteria for AS.

Magnetic Resonance Imaging-Transrectal Ultrasound Guided Fusion Biopsy to Detect Progression in Patients with Existing Lesions on Active Surveillance for Low and Intermediate Risk Prostate Cancer

PURPOSE

Active surveillance is an established option for men with low risk prostate cancer. Multiparametric magnetic resonance imaging with magnetic resonance imaging-transrectal ultrasound fusion guided biopsy may better identify patients for active surveillance compared to systematic 12-core biopsy due to improved risk stratification. To our knowledge the performance of multiparametric magnetic resonance imaging in following men on active surveillance with visible lesions is unknown. We evaluated multiparametric magnetic resonance imaging and magnetic resonance imaging-transrectal ultrasound fusion guided biopsy to monitor men on active surveillance.

MATERIALS AND METHODS

This retrospective review included men from 2007 to 2015 with prostate cancer on active surveillance in whom magnetic resonance imaging visible lesions were monitored by multiparametric magnetic resonance imaging and fusion guided biopsy. Progression was defined by ISUP (International Society of Urological Pathology) grade group 1 to 2 and ISUP grade group 2 to 3. Significance was considered at p ≤0.05.

RESULTS

A total of 166 patients on active surveillance with 2 or more fusion guided biopsies were included in analysis. Mean followup was 25.5 months. Of the patients 29.5% had pathological progression. Targeted biopsy alone identified 44.9% of patients who progressed compared to 30.6% identified by systematic 12-core biopsy alone (p = 0.03). Fusion guided biopsy detected 26% more cases of pathological progression on surveillance biopsy compared to systematic 12-core biopsy. Progression on multiparametric magnetic resonance imaging was the sole predictor of pathological progression at surveillance biopsy (p = 0.013). Multiparametric magnetic resonance imaging progression in the entire cohort had 81% negative predictive value, 35% positive predictive value, 77.6% sensitivity and 40.5% specificity in detecting pathological progression.

CONCLUSIONS

Multiparametric magnetic resonance imaging progression predicts the risk of pathological progression. Patients with stable multiparametric magnetic resonance imaging findings have a low rate of progression. Incorporating fusion guided biopsy in active surveillance nearly doubled our detection of pathological progression compared to systematic 12-core biopsy.

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.

Active surveillance for prostate cancer: current evidence and contemporary state of practice

Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

Active surveillance in Canadian men with low-grade prostate cancer

BACKGROUND

Recent guidelines recommend against routine screening for prostate cancer, partly because of the risks associated with overtreatment of clinically indolent tumours. We aimed to determine the proportion of patients whose low-grade prostate cancer was managed by active surveillance instead of immediate treatment.

METHODS

We reviewed data for patients who were referred to the Ottawa regional Prostate Cancer Assessment Clinic with abnormal results for prostate-specific antigen (PSA) or prostate examination between Apr. 1, 2008, and Jan. 31, 2013. Patients with subsequent biopsy-proven low-grade (Gleason score 6) cancer were included. Active surveillance was defined a priori as monitoring by means of PSA, digital rectal examination and repeat biopsies, with the potential for curative-intent treatment in the event of disease progression.

RESULTS

Of 477 patients with low-grade cancer, active surveillance was used for 210 (44.0%), and the annual proportion increased from 32% (11/34) in 2008 to 67% (20/30) in 2013. Factors associated with immediate treatment were palpable tumour, PSA density above 0.2 ng/mL(2) and more than 2 positive biopsy cores. Factors associated with surveillance were age over 70 years and higher Charlson comorbidity index. Of 173 men who received immediate surgical treatment, 103 (59.5%) had higher-grade or advanced-stage disease on final pathologic examination. Of the 210 men with active surveillance, 62 (29.5%) received treatment within a median of 1.3 years, most commonly (52 [84%]) because of upgrading of disease on the basis of surveillance biopsy.

INTERPRETATION

Active surveillance has become the most common management strategy for men with low-grade prostate cancer at our regional diagnostic centre. Factors associated with immediate treatment reflected those that increase the risk of higher-grade tumours.

Can MRI/TRUS fusion targeted biopsy replace saturation prostate biopsy in the re-evaluation of men in active surveillance?

PURPOSE

The detection rate for significant prostate cancer of mMRI/TRUS fusion targeted biopsy versus saturation prostate biopsy was prospectively evaluated in men enrolled in active surveillance (AS) protocol.

METHODS

From May 2013 to January 2015, 40 men aged 66 years (median) with very low-risk PCa were enrolled in an AS protocol, and eligible criteria were: life expectancy greater than 10 years, cT1C, PSA below 10 ng/ml, PSA density <0.20, ≤2 unilateral positive biopsy cores, Gleason score (GS) equal to 6, greatest percentage of cancer (GPC) in a core ≤50 %. All patients underwent 3.0-Tesla pelvic mpMRI before confirmatory transperineal saturation biopsy (SPBx; median 30 cores) combined with mpMRI/TRUS fusion targeted biopsy (median 4 cores) of suspicious lesions (PI-RADS 4-5).

RESULTS

Ten out of 40 (25 %) patients were reclassified by SPBx based on upgraded GS ≥ 7; mpMRI found all the lesions predictive of significant PCa showing a false-positive rate equal to 5 %; on the contrary, mpMRI/TRUS targeted biopsy missed 3/10 (30 %) significant PCa characterised by the presence of a single positive core of GS ≥ 7 and GPC ≤ 5 %, suggesting that reduced number of targeted biopsies could miss small but significant PCa. Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value of mpMRI in diagnosing significant PCa were 95.2, 100, 93.8, 83.4, 100 %, respectively.

CONCLUSIONS

Although mpMRI provided high diagnostic accuracy (about 95 %) in diagnosing clinically significant PCa, mpMRI/TRUS fusion targeted biopsy cannot replace SPBx at confirmatory biopsy of men enrolled in AS protocols.

Analysis of expanded criteria to select candidates for active surveillance of low-risk prostate cancer

We aimed to analyze the value of each criterion for clinically insignificant prostate cancer (PCa) in the selection of men for active surveillance (AS) of low-risk PCa. We identified 532 men who were treated with radical prostatectomy from 2006 to 2013 who met 4 or all 5 of the criteria for clinically insignificant PCa (clinical stage ≤ T1, prostate specific antigen [PSA] density ≤ 0.15, biopsy Gleason score ≤ 6, number of positive biopsy cores ≤ 2, and no core with > 50% involvement) and analyzed their pathologic and biochemical outcomes. Patients who met all 5 criteria for clinically insignificant PCa were designated as group A (n = 172), and those who met 4 of 5 criteria were designated as group B (n = 360). The association of each criterion with adverse pathologic features was assessed via logistic regression analyses. Comparison of group A and B and also logistic regression analyses showed that PSA density > 0.15 ng ml⁻¹ and high (≥7) biopsy Gleason score were associated with adverse pathologic features. Higher (> T1c) clinical stage was not associated with any adverse pathologic features. Although ≤ 3 positive cores were not associated with any adverse pathology, ≥4 positive cores were associated with higher risk of extracapsular extension. Among potential candidates for AS, PSA density > 0.15 ng ml⁻¹ and biopsy Gleason score > 6 pose significantly higher risks of harboring more aggressive disease. The eligibility criteria for AS may be expanded to include men with clinical stage T2 tumor and 3 positive cores.

Occult High-risk Disease in Clinically Low-risk Prostate Cancer with ≥50% Positive Biopsy Cores: Should National Guidelines Stop Calling Them Low Risk?

OBJECTIVE

To identify contemporary, clinically low-risk patients with ≥50% cores positive and compare the risk of upgrading at prostatectomy with other low- or intermediate-risk patients.

MATERIALS AND METHODS

We studied 14,902 patients with prostate cancer in the Surveillance, Epidemiology, and End Results database in 2010-2011 treated with prostatectomy. Patients were categorized by National Comprehensive Cancer Network clinical risk groups, separating low-risk patients by percent positive biopsy cores (PBC). We measured incidence of pathologic high-risk disease, defined as pT3a-T4 or Gleason 8-10, and multivariable logistic regression was used to determine if patients with clinical low-risk disease and ≥50% PBC were similar to other low- or intermediate-risk patients. This analysis was repeated with favorable and unfavorable intermediate risk.

RESULTS

At prostatectomy, 9.2% of clinically low-risk patients with <50% PBC, 18.6% of clinically low-risk patients with ≥50% PBC, and 27.6% of clinically intermediate-risk patients had occult, high-risk disease (P <.001). On multivariable logistic regression, low-risk patients with ≥50% PBC were more likely than low-risk patients with <50% PBC to have pathologic high-risk disease (adjusted odds ratio [AOR] 2.28, 95% confidence interval 1.90-2.73, P <.001), had similar risk to favorable intermediate patients overall (AOR 1.09, 0.91-1.31, P = .33), and had higher risk than favorable intermediate patients aged over 60 years (AOR 1.28, 1.00-1.64, P = .04). Low-risk patients with ≥50% PBC had a mean tumor size similar to unfavorable intermediate-risk patients (21.3 vs 21.0 mm, P = .82).

CONCLUSION

Nearly 1 in 5 clinically low-risk prostate cancer patients with ≥50% PBC harbor occult pT3a-T4 or Gleason 8-10, suggesting that national guidelines should not classify low-risk patients with ≥50% cores positive as "low risk," and patients should be made aware of this excess risk if considering active surveillance.

Pathologic Outcomes in Men with Low-risk Prostate Cancer Who Are Potential Candidates for Contemporary, Active Surveillance Protocols

The purpose of this study was to determine whether contemporary active surveillance (AS) protocols could sufficiently discriminate significant from indolent tumors in men with low-risk prostate cancer. We retrospectively analyzed 312 patients with low-risk prostate cancer treated with radical prostatectomy. After exclusion of patients with fewer than 10 cores taken at biopsy and those who received neo-adjuvant treatment, 205 subjects satisfied the final inclusion criteria. Five widely accepted AS protocols were employed in this study. A total of 82.0% of the patients met the inclusion criteria of at least one protocol, and 18% did not meet any criteria of published AS protocols. A significant proportion of patients had non-organ-confined disease (8.6% to 10.6%) or a Gleason score of 7 or greater (18.6% to 23.9%) between the different AS criteria. Among patients who did not meet any AS criteria, 32.4% of patients had a pathologically insignificant cancer. Our results indicated a significant adverse pathology in patients who met the contemporary AS protocols. On the other hand, some patients in whom expectant management would be appropriate did not meet any criteria of published AS protocols. None of the clinical or histological criteria reported to date is able to sufficiently discriminate aggressive tumors from indolent ones.

Characteristics and experiences of patients with localized prostate cancer who left an active surveillance program

BACKGROUND

Understanding the experiences of men leaving active surveillance programs is critical to making such programs viable for men with localized prostate cancer.

OBJECTIVE

To generate hypotheses about the factors that influence patients' decisions to leave an active surveillance program.

METHODS

Using data from the Johns Hopkins active surveillance cohort, bivariate analyses and multinomial regression models examined characteristics of men who self-elected to leave, those who stayed in the program, and those who left because of disease reclassification. We interviewed patients who self-elected to leave.

RESULTS

Of 1,159 men in active surveillance, 9 % self-elected to leave. In interviews with a sample of 14 men who self-elected to leave, uncertainty involved in active surveillance participation, existence of personal criteria-distinct from providers' clinical criteria-and fear of cancer were important factors in decisions to leave.

CONCLUSION

Men leaving active surveillance were motivated by a number of factors, including patient-defined criteria, which might differ from clinical recommendations. To ensure active surveillance participation, it may be important to address cancer-related anxiety and personal criteria underlying patient decisions.

PTEN loss is associated with upgrading of prostate cancer from biopsy to radical prostatectomy

When distinguishing between indolent and potentially harmful prostate cancers, the Gleason score is the most important variable, but may be inaccurate in biopsies due to tumor under-sampling. This study investigated whether a molecular feature, PTEN protein loss, could help identify which Gleason score 6 tumors on biopsy are likely to be upgraded at radical prostatectomy. Seventy one patients with Gleason score 6 tumors on biopsy upgraded to Gleason score 7 or higher at prostatectomy (cases) were compared with 103 patients with Gleason score 6 on both biopsy and prostatectomy (controls). A validated immunohistochemical assay for PTEN was performed, followed by fluorescence in situ hybridization (FISH) to detect PTEN gene deletion in a subset. PTEN protein loss and clinical-pathologic variables were assessed by logistic regression. Upgraded patients were older than controls (61.8 vs 59.3 years), had higher pre-operative PSA levels (6.5 vs 5.3 ng/ml) and a higher fraction of involved cores (0.42 vs 0.36). PTEN loss by immunohistochemistry was found in 18% (13/71) of upgraded cases compared with 7% (7/103) of controls (P=0.02). Comparison between PTEN immunohistochemistry and PTEN FISH showed the assays were highly concordant, with 97% (65/67) of evaluated biopsies with intact PTEN protein lacking PTEN gene deletion, and 81% (13/16) of the biopsies with PTEN protein loss showing homozygous PTEN gene deletion. Tumors with PTEN protein loss were more likely to be upgraded at radical prostatectomy than those without loss, even after adjusting for age, preoperative PSA, clinical stage and race (odds ratio=3.04 (1.08-8.55; P=0.035)). PTEN loss in Gleason score 6 biopsies identifies a subset of prostate tumors at increased risk of upgrading at radical prostatectomy. These data provide evidence that a genetic event can improve Gleason score accuracy and highlight a path toward the clinical use of molecular markers to augment pathologic grading.

Does cumulative prostate cancer length (CCL) in prostate biopsies improve prediction of clinically insignificant cancer at radical prostatectomy in patients eligible for active surveillance?

OBJECTIVES

To evaluate if cumulative prostate cancer length (CCL) on prostate needle biopsy divided by the number of biopsy cores (CCL/core) could improve prediction of insignificant cancer on radical prostatectomy (RP) in patients with prostate cancer eligible for active surveillance (AS).

PATIENTS AND METHODS

Patients diagnosed with prostate cancer on extended (≥10 cores) biopsy with an initial prostate-specific antigen (iPSA) level of <15 ng/mL, clinical stage (cT) ≤ 2a, and highest biopsy Gleason score 3 + 3 = 6 or 3 + 4 = 7 with <3 positive cores who underwent RP were included in the study. The CCL/core and presence of insignificant cancer (organ-confined, volume <0.5 mL, Gleason score at RP ≤6) were recorded. pT2 prostate cancer with RP Gleason score ≤3 + 4 = 7 and volume <0.5 mL were categorised as low-tumour-volume organ-confined disease (LV-OCD).

RESULTS

In all, 221 patients met the inclusion criteria: the mean age was 59 years and the median iPSA level was 4.5 ng/mL. The clinical stage was cT1 in 86% of patients; biopsy Gleason score was 3 + 3 = 6 in 67% (group 1) and 3 + 4 = 7 in 33% of patients (group 2). The maximum percentage of biopsy core involvement was <50 in 85%; the median CCL/core was 0.15 mm. Insignificant cancer was found in 27% and LV-OCD in 44% of patients. Group 2 was associated with higher number of positive cores, maximum percentage core involvement, total prostate cancer length, and CCL/core. Group 1 was more likely to have insignificant cancer (39%) or LV-OCD (54%) than group 2 (3% and 23%, respectively). Group 2 had significantly higher RP Gleason score and pathological stage. Univariate analysis of group 1 showed that the iPSA level, maximum percentage core involvement, prostate cancer length, and CCL/core were all significantly associated with insignificant cancer and LV-OCD. For group 2, the number of positive cores (1 vs 2) was also significantly associated with LV-OCD. On multivariate logistic regression analysis, maximum percentage core involvement of <50, and number of positive cores (1 vs 2) were independent predictors of insignificant cancer in group 1; biopsy Gleason score, maximum percentage core involvement of <50 and prostate cancer length of <3 mm or CCL/core of <0.2 mm were all independent predictors of LV-OCD in the whole population. The maximum percentage of core involvement of <50 and prostate cancer length of <3 mm or CCL/core of <0.2 mm were also independent predictors of LV-OCD in group 1 patients.

CONCLUSION

In patients eligible for AS, a CCL/core of <0.20 mm was significantly associated with insignificant cancer and LV-OCD. However, when parameters of cancer burden were considered, CCL/core did not independently add any additional value for predicting insignificant cancer in patients with biopsy Gleason score 6. The CCL/core was an independent predictor of LV-OCD in the whole population and in group 1 patients, although the model including prostate cancer length showed slightly higher area under the receiver operating characteristic curve.

Contemporary use of initial active surveillance among men in Michigan with low-risk prostate cancer

BACKGROUND

Active surveillance (AS) has been proposed as an effective strategy to reduce overtreatment among men with lower risk prostate cancers. However, historical rates of initial surveillance are low (4-20%), and little is known about its application among community-based urology practices.

OBJECTIVE

To describe contemporary utilization of AS among a population-based sample of men with low-risk prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed a prospective cohort study of men with low-risk prostate cancer managed by urologists participating in the Michigan Urological Surgery Improvement Collaborative (MUSIC).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The principal outcome was receipt of AS as initial management for low-risk prostate cancer including the frequency of follow-up prostate-specific antigen (PSA) testing, prostate biopsy, and local therapy. We examined variation in the use of surveillance according to patient characteristics and across MUSIC practices. Finally, we used claims data to validate treatment classification in the MUSIC registry.

RESULTS AND LIMITATIONS

We identified 682 low-risk patients from 17 MUSIC practices. Overall, 49% of men underwent initial AS. Use of initial surveillance varied widely across practices (27-80%; p=0.005), even after accounting for differences in patient characteristics. Among men undergoing initial surveillance with at least 12 mo of follow-up, PSA testing was common (85%), whereas repeat biopsy was performed in only one-third of patients. There was excellent agreement between treatment assignments in the MUSIC registry and claims data (κ=0.93). Limitations include unknown treatment for 8% of men with low-risk cancer.

CONCLUSIONS

Half of men in Michigan with low-risk prostate cancer receive initial AS. Because this proportion is much higher than reported previously, our findings suggest growing acceptance of this strategy for reducing overtreatment.

PATIENT SUMMARY

We examined the use of initial active surveillance for the management of men with low-risk prostate cancer across the state of Michigan. We found that initial surveillance is used much more commonly than previously reported, but the likelihood of a patient being placed on surveillance depends strongly on where he is treated.

Outcomes of men with an elevated prostate-specific antigen (PSA) level as their sole preoperative intermediate- or high-risk feature

OBJECTIVE

To investigate the post-prostatectomy and long-term outcomes of men presenting with an elevated pretreatment prostate-specific antigen (PSA) level (>10 ng/mL), but otherwise low-risk features (biopsy Gleason score ≤6 and clinical stage ≤T2a).

PATIENTS AND METHODS

PSA-incongruent intermediate-risk (PII) cases were defined as those patients with preoperative PSA >10 and ≤20 ng/mL but otherwise low-risk features, and PSA-incongruent high-risk (PIH) cases were defined as men with PSA >20 ng/mL but otherwise low-risk features. Our institutional radical prostatectomy database (1992-2012) was queried and the results were stratified into D'Amico low-, intermediate- and high risk, PSA-incongruent intermediate-risk and PSA-incongruent high-risk cases. Prostate cancer (PCa) features and outcomes were evaluated using appropriate comparative tests. Multivariable analyses were adjusted for age, race and year of surgery.

RESULTS

Of the total cohort of 17 608 men, 1132 (6.4%) had PII-risk disease and 183 (1.0%) had PIH-risk disease. Compared with the low-risk group, the odds of upgrading at radical prostatectomy (RP) were 2.20 (95% CI 1.93-2.52; P < 0.001) for the PII group and 3.58 (95% CI 2.64-4.85; P < 0.001) for the PIH group, the odds of extraprostatic disease at RP were 2.35 (95% CI 2.05-2.68; P < 0.001) for the PII group and 6.68 (95% CI 4.89-9.15; P < 0.001) for the PIH group, and the odds of positive surgical margins were 1.97 (95% CI 1.67-2.33; P < 0.001) for the PII group and 3.54 (95% CI 2.50-4.95, P < 0.001) for the PIH group. Compared with low-risk disease, PII-risk disease was associated with a 2.85-, 2.99- and 3.32-fold greater risk of biochemical recurrence (BCR), metastasis and PCa-specific mortality, respectively, and PIH-risk disease was associated with a 5.32-, 6.14- and 7.07-fold greater risk of BCR, metastasis and PCa-specific mortality, respectively (P ≤ 0.001 for all comparisons). For the PII group, the higher risks of positive surgical margins, upgrading, upstaging and BCR were dependent on PSA density (PSAD): men in the PII group who had a PSAD <0.15 ng/mL/g were not at higher risk compared with those in the low-risk group. Men in the PII group with a PSAD ≥0.15 ng/mL/g and men in the PIH group were more likely to have an anterior component of the dominant tumour (59 and 64%, respectively) compared with those in the low- (35%) and intermediate-risk group (39%) and those in the PII-risk group with PSAD <0.15 ng/mL/g (29%).

CONCLUSIONS

Men with PSA >20 ng/mL or men with PSA >10 and ≤20 ng/mL with a PSAD ≥0.15 ng/mL/g, but otherwise low-risk PCa, are at greater risk of adverse pathological and oncological outcomes and may be inappropriate candidates for active surveillance. These men are at greater risk of having anterior tumours that are undersampled at biopsy, so if treatment is deferred, ancillary testing such as anterior zone sampling or magnetic resonance imaging should be strongly encouraged. Men with elevated PSA levels >10 and ≤20 ng/mL but low PSAD have outcomes similar to those in the low-risk group, and consideration of surveillance is appropriate in these cases.

Gene signatures ESC, MYC and ERG-fusion are early markers of a potentially dangerous subtype of prostate cancer

Background

Good prognostic tools for predicting disease progression in early stage prostate cancer (PCa) are still missing. Detection of molecular subtypes, for instance by using microarray gene technology, can give new prognostic information which can assist personalized treatment planning. The detection of new subtypes with validation across additional and larger patient cohorts is important for bringing a potential prognostic tool into the clinic.

Methods

We used fresh frozen prostatectomy tissue of high molecular quality to further explore four molecular subtype signatures of PCa based on Gene Set Enrichment Analysis (GSEA) of 15 selected gene sets published in a previous study. For this analysis we used a statistical test of dependent correlations to compare reference signatures to signatures in new normal and PCa samples, and also explore signatures within and between sample subgroups in the new samples.

Results

An important finding was the consistent signatures observed for samples from the same patient independent of Gleason score. This proves that the signatures are robust and can surpass a normally high tumor heterogeneity within each patient. Our data did not distinguish between four different subtypes of PCa as previously published, but rather highlighted two groups of samples which could be related to good and poor prognosis based on survival data from the previous study.The poor prognosis group highlighted a set of samples characterized by enrichment of ESC, ERG-fusion and MYC + rich signatures in patients diagnosed with low Gleason score,. The other group consisted of PCa samples showing good prognosis as well as normal samples. Accounting for sample composition (the amount of benign structures such as stroma and epithelial cells in addition to the cancer component) was important to improve subtype assignments and should also be considered in future studies.

Conclusion

Our study validates a previous molecular subtyping of PCa in a new patient cohort, and identifies a subgroup of PCa samples highly interesting for detecting high risk PCa at an early stage. The importance of taking sample tissue composition into account when assigning subtype is emphasized.

Prostate volume and biopsy tumor length are significant predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy

Background

Gleason pattern 3 less often has molecular abnormalities and often behaves indolent. It is controversial whether low grade small foci of prostate cancer (PCa) on biopsy could avoid immediate treatment or not, because substantial cases harbor unfavorable pathologic results on prostatectomy specimens. This study was designed to identify clinical predictors for classical and redefined insignificant cancer on prostatectomy specimens in Japanese men with favorable pathologic features on biopsy.

Methods

Retrospective review of 1040 PCa Japanese patients underwent radical prostatectomy between 2006 and 2013. Of those, 170 patients (16.3%) met the inclusion criteria of clinical stage ≤ cT2a, Gleason score (GS) ≤ 6, up to two positive biopsies, and no more than 50% of cancer involvement in any core. The associations between preoperative data and unfavorable pathologic results of prostatectomy specimens, and oncological outcome were analyzed. The definition of insignificant cancer consisted of pathologic stage ≤ pT2, GS ≤ 6, and an index tumor volume < 0.5 mL (classical) or 1.3 mL (redefined).

Results

Pathologic stage ≥ pT3, upgraded GS, index tumor volume ≥ 0.5 mL, and ≥ 1.3 mL were detected in 25 (14.7%), 77 (45.3%), 83 (48.8%), and 53 patients (31.2%), respectively. Less than half of cases had classical (41.2%) and redefined (47.6%) insignificant cancer. The 5-year recurrence-free survival was 86.8%, and the insignificant cancers essentially did not relapse regardless of the surgical margin status. MRI-estimated prostate volume, tumor length on biopsy, prostate-specific antigen density (PSAD), and findings of magnetic resonance imaging were associated with the presence of classical and redefined insignificant cancer. Large prostate volume and short tumor length on biopsy remained as independent predictors in multivariate analysis.

Conclusions

Favorable features of biopsy often are followed by adverse pathologic findings on prostatectomy specimens despite fulfilling the established criteria. The finding that prostate volume is important does not simply mirror many other studies showing PSAD is important, and the clinical criteria for risk assessment before definitive therapy or active surveillance should incorporate these significant factors other than clinical T-staging or PSAD to minimize under-estimation of cancer in Japanese patients with low-risk PCa.

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.