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

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.

[Prostate Imaging Reporting and Data System (PI-RADS) v 2.1: Overview and Critical Points]

The technical parameters and imaging interpretation criteria of the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) using multiparametric MRI (mpMRI) are updated in PI-RADS v2.1. These changes have been an expected improvement for prostate cancer evaluation, although some issues remain unsolved, and new issues have been raised. In this review, a brief overview of PI-RADS v2.1 is and several critical points are discussed as follows: the need for more detailed protocols of mpMRI, lack of validation of the revised transition zone interpretation criteria, the need for clarification for the revised diffusion-weighted imaging and dynamic contrast-enhanced imaging criteria, anterior fibromuscular stroma and central zone assessment, assessment of background signal and tumor aggressiveness, changes in the structured report, the need for the parameters for imaging quality and performance control, and indications for expansion of the system to include other indications.

Progress in prostate cancer prevention

After lung, prostate cancer is the second most frequently diagnosed cancer and fourth in cancer-related mortality. The etiology is largely unknown and no clear risk factors have been identified. Primary prevention is therefore challenging. Also, secondary prevention, screening, in large populations is difficult. Germline mutations are implicated in hereditary prostate cancer, accounting for about 10% of screened men. Currently, only prostate-specific antigen test is adopted for early detection but is considered insufficient to further improve prevention and care. In this opinion article, we discuss novel diagnostic biomarkers and imaging tools, along with more promising targeted prostate biopsies.

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.

Active surveillance for prostate cancer: comparison between incidental tumors vs. tumors diagnosed at prostate biopsies

PURPOSE

To test discontinuation rates during Active Surveillance (AS) in patients diagnosed with incidental prostate cancers (IPCa) vs. tumors diagnosed at prostate biopsies (BxPCa).

METHODS

Retrospective single center analysis of 961 vs. 121 BxPCa vs. IPCa patients (2008-2020). Kaplan-Meier plots and multivariable Cox regression models tested four different outcomes: (1) any-cause discontinuation; (2) discontinuation due to ISUP GG upgrading; (3) biopsy discontinuation due to ISUP GG upgrading or > 3 positive cores; (4) biopsy discontinuation or suspicious extraprostatic extension at surveillance mpMRI. Then, multivariable logistic regression models tested rates of clinically significant PCa (csPCa) (ISUP GG ≥ 3 or pT ≥ 3a or pN1) after radical prostatectomy (RP).

RESULTS

Median time follow-up was 35 (19-64) months. IPCa patients were at lower risk of any-cause (3-year survival: 79.3 vs. 66%; HR: 0.5, p = 0.001) and biopsy/MRI AS discontinuation (3-year survival: 82.3 vs. 72.7%; HR: 0.5, p = 0.001), compared to BxPCa patients. Conversely, IPCa patients exhibited same rates of biopsy discontinuation and ISUP GG upgrading over time, relative to BxPCa. In multivariable logistic regression models, IPCa patients were associated with higher rates of csPCa at RP (OR: 1.4, p = 0.03), relative to their BxPCa counterparts.

CONCLUSION

AS represents a safe management strategy for IPCa. Compared to BxPCa, IPCa patients are less prone to experience any-cause and biopsy/MRI AS discontinuation. However, the two mentioned groups present similar rates of biopsy discontinuation and ISUP GG upgrading over time. In consequence, tailored AS protocols with scheduled repeated surveillance biopsies should be offered to all newly diagnosed IPCa patients.

Repeat MRI during active surveillance: natural history of prostatic lesions and upgrading rates

OBJECTIVES

To assess upgrading rates in patients on active surveillance (AS) for prostate cancer (PCa) after serial multiparametric magnetic resonance imaging (mpMRI).

METHODS

We conducted a retrospective analysis of 558 patients. Five different criteria for mpMRI progression were used: 1) a Prostate Imaging Reporting and Data System (PI-RADS) score increase; 2) a lesion size increase; 3) an extraprostatic extension score increase; 4) overall mpMRI progression; and 5) the number of criteria met for mpMRI progression (0 vs 1 vs 2-3). In addition, two definitions of PCa upgrading were evaluated: 1) International Society of Urological Pathology Grade Group (ISUP GG) ≥2 with >10% of pattern 4 and 2) ISUP GG ≥ 3. Estimated annual percent changes methodology was used to show the temporal trends of mpMRI progression criteria. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of mpMRI progression criteria were also analysed. Multivariable logistic regression models tested PCa upgrading rates.

RESULTS

Lower rates over time for all mpMRI progression criteria were observed. The NPV of serial mpMRI scans ranged from 90.5% to 93.5% (ISUP GG≥2 with >10% of pattern 4 PCa upgrading) and from 98% to 99% (ISUP GG≥3 PCa upgrading), depending on the criteria used for mpMRI progression. A prostate-specific antigen density (PSAD) threshold of 0.15 ng/mL/mL was used to substratify those patients who would be able to skip a prostate biopsy. In multivariable logistic regression models assessing PCa upgrading rates, all five mpMRI progression criteria achieved independent predictor status.

CONCLUSION

During AS, approximately 27% of patients experience mpMRI progression at first repeat MRI. However, the rates of mpMRI progression decrease over time at subsequent mpMRI scans. Patients with stable mpMRI findings and with PSAD < 0.15 ng/mL/mL could safely skip surveillance biopsies. Conversely, patients who experience mpMRI progression should undergo a prostate biopsy.

Serum miRNAs Support the Indication for MRI-Ultrasound Fusion-Guided Biopsy of the Prostate in Patients with Low-PI-RADS Lesions

Multiparametric MRI (mpMRI) and targeted biopsy of the prostate enhance the tumor detection rate. However, the prediction of clinically significant prostate cancer (PCa) is still limited. Our study tested the additional value of serum levels of selected miRNAs in combination with clinical and mpMRI information for PCa prediction and classification. A total of 289 patients underwent targeted mpMRI-ultrasound fusion-guided prostate biopsy complemented by systematic biopsy. Serum miRNA levels of miRNAs (miR-141, miR-375, miR-21-5p, miR-320b, miR-210-3p, let-7c, and miR-486) were determined by quantitative PCR. Detection of any PCa and of significant PCa were the outcome variables. The patient age, pre-biopsy PSA level, previous biopsy procedure, PI-RADS score, and serum miRNA levels were covariates for regularized binary logistic regression models. The addition of miRNA expression of miR-486 and let-7c to the baseline model, containing only clinical parameters, increased the predictive accuracy. Particularly in patients with PI-RADS ≤3, we determined a sensitivity for detecting significant PCa (Gleason score ≥ 7a corresponding to Grade group ≥2) of 95.2%, and an NPV for absence of significant PCa of 97.1%. This accuracy could be useful to support patient counseling in selected cases.

MRI-targeted prostate biopsy: the next step forward!

Aim

For decades, the gold standard technique for diagnosing prostate cancer was the 10 to 12 core systematic transrectal or transperineal biopsy, under ultrasound guidance. Over the past years, an increased rate of false negative results and detection of clinically insignificant prostate cancer has been noted, resulting into overdiagnosis and overtreatment. The purpose of the current study was to evaluate the changes in diagnosis and management of prostate cancer brought by MRI-targeted prostate biopsy.

Methods

A critical review of literature was carried out using the Medline database through a PubMed search, 37 studies meeting the inclusion criteria: prospective studies published in the past 8 years with at least 100 patients per study, which used multiparametric magnetic resonance imaging as guidance for targeted biopsies.

Results

In-Bore MRI targeted biopsy and Fusion targeted biopsy outperform standard systematic biopsy both in terms of overall and clinically significant prostate cancer detection, and ensure a lower detection rate of insignificant prostate cancer, with fewer cores needed. In-Bore MRI targeted biopsy performs better than Fusion biopsy especially in cases of apical lesions.

Conclusion

Targeted biopsy is an emerging and developing technique which offers the needed improvements in diagnosing clinically significant prostate cancer and lowers the incidence of insignificant ones, providing a more accurate selection of the patients for active surveillance and focal therapies.

Old men with prostate cancer have higher risk of Gleason score upgrading and pathological upstaging after initial diagnosis: a systematic review and meta-analysis

BACKGROUND

To evaluate the predictive performance of age for the risk of Gleason score change and pathologic upstaging.

EVIDENCE ACQUISITION

Ovid MEDLINE, Ovid Embase, and the Cochrane Library were searched from inception until May 2020. Quality of included studies was appraised utilizing the Newcastle-Ottawa Quality Assessment Scale for case-control studies. The publication bias was evaluated by funnel plots and Egger's tests.

EVIDENCE SYNTHESIS

Our search yielded 27 studies with moderate-to-high quality including 84296 patients with mean age of 62.1 years. From biopsy to prostatectomy, upgrading and upstaging occurred in 32.3% and 9.8% of patients, respectively. Upgrading from diagnostic biopsy to confirmatory biopsy was found in 16.8%. Older age was associated with a significant increased risk of upgrading (OR 1.04, 95% CI 1.03-1.05), and similar direction of effect was found in studies focused on upgrading from diagnostic biopsy to confirmatory biopsy (OR 1.06, 95% CI 1.04-1.08). For pathologic upstaging within older men compared with younger, the pooled odds was 1.03 (95% CI 1.01-1.04).

CONCLUSION

Thorough consideration of age in the context of effect sizes for other factors not only prompts more accurate risk stratification but also helps providers to select optimal therapies for patients with prostate cancer.

PI-RADS Version 2.1: A Critical Review, From the AJR Special Series on Radiology Reporting and Data Systems

PI-RADS version 2.1 updates the technical parameters for multiparametric MRI (mpMRI) of the prostate and revises the imaging interpretation criteria while maintaining the framework introduced in version 2. These changes have been considered an improvement, although some issues remain unresolved, and new issues have emerged. Areas for improvement discussed in this review include the need for more detailed mpMRI protocols with optimization for 1.5-T and 3-T systems; lack of validation of revised transition zone interpretation criteria and need for clarifications of the revised DWI and dynamic contrast-enhanced imaging criteria and central zone (CZ) assessment; the need for systematic evaluation and reporting of background changes in signal intensity in the prostate that can negatively affect cancer detection; creation of a new category for lesions that do not fit into the PI-RADS assessment categories (i.e., PI-RADS M category); inclusion of quantitative parameters beyond size to evaluate lesion aggressiveness; adjustments to the structured report template, including standardized assessment of the risk of extraprostatic extension; development of parameters for image quality and performance control; and suggestions for expansion of the system to other indications (e.g., active surveillance and recurrence).

Impact of PI-RADS Category 3 lesions on the diagnostic accuracy of MRI for detecting prostate cancer and the prevalence of prostate cancer within each PI-RADS category: A systematic review and meta-analysis

OBJECTIVE

To evaluate Prostate Imaging Reporting and Data System (PI-RADS) category 3 lesions' impact on the diagnostic test accuracy (DTA) of MRI for prostate cancer (PC) and to derive the prevalence of PC within each PI-RADS category.

METHODS

MEDLINE and Embase were searched until April 10, 2020 for studies reporting on the DTA of MRI by PI-RADS category. Accuracy metrics were calculated using a bivariate random-effects meta-analysis with PI-RADS three lesions treated as a positive test, negative test, and excluded from the analysis. Differences in DTA were assessed utilizing meta-regression. PC prevalence within each PI-RADS category was estimated with a proportional meta-analysis.

RESULTS

In total, 26 studies reporting on 12,913 patients (4,853 with PC) were included. Sensitivities for PC in the positive, negative, and excluded test groups were 96% (95% confidence interval [CI] 92-98), 82% (CI 75-87), and 95% (CI 91-97), respectively. Specificities for the positive, negative, and excluded test groups were 33% (CI 23-44), 71% (CI 62-79), and 52% (CI 37-66), respectively. Meta-regression demonstrated higher sensitivity (p < 0.001) and lower specificity (p < 0.001) in the positive test group compared to the negative group. Clinically significant PC prevalences were 5.9% (CI 0-17.1), 11.4% (CI 6.5-17.3), 24.9% (CI 18.4-32.0), 55.7% (CI 47.8-63.5), and 81.4% (CI 75.9-86.4) for PI-RADS categories 1, 2, 3, 4 and 5, respectively.

CONCLUSION

PI-RADS category 3 lesions can significantly impact the DTA of MRI for PC detection. A low prevalence of clinically significant PC is noted in PI-RADS category 1 and 2 cases.

ADVANCES IN KNOWLEDGE

Inclusion or exclusion of PI-RADS category 3 lesions impacts the DTA of MRI for PC detection.

Current Role of Multiparametric MRI and MRI Targeted Biopsies for Prostate Cancer Diagnosis in Germany: A Nationwide Survey

INTRODUCTION

Multiparametric MRI (mpMRI) and MRI targeted biopsies (MRtb) are a new standard in prostate cancer (PCa) screening and diagnosis. Guidelines already include this approach for patients at risk. We aimed to gather information from German urologists about their knowledge, routine use, and attitude toward mpMRI and consecutive biopsy methods.

MATERIALS AND METHODS

An anonymous online questionnaire was sent via Survey Monkey to the members of the German Society of Urology (DGU). Statistical analyses were performed using SPSS version 25.0.

RESULTS

496 members with a median age of 48.6 years (±11.7) participated in the survey. The majority rated mpMRI of the prostate as a very useful diagnostic tool (72.7%). MRtb of the prostate was considered as very advantageous (71.5%). MpMRI was used by 95.9%, and 83.2% also recommended MRtb predominantly in clinical institutions. For targeted biopsy, MRI-ultrasound fusion biopsy was clearly favored (75.8%). MpMRI was mostly used in patients with previously negative biopsy (90.9%) and in patients under active surveillance (60.9%). Arguments against the use of prostate mpMRI are costs (84.9%) and/or lack of sufficient radiological infrastructure (17.4%).

CONCLUSION

Our data illustrate the meanwhile high acceptance and clinical use of the prostate mpMRI and MRtb in Germany.

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.

Pathological findings at radical prostatectomy of biopsy naïve men diagnosed with MRI targeted biopsy alone without concomitant standard systematic sampling

OBJECTIVES

To test international society of urological pathology grade group (ISUP GG) concordance rates between multiparametric magnetic resonance imaging (mpMRI) targeted biopsies (TB) vs. standard systematic biopsies (SB) and radical prostatectomy (RP) specimens, in biopsy naïve patients.

MATERIALS AND METHODS

This retrospective single center study included 80 vs. 500 biopsy naïve patients diagnosed with TB vs. SB and treated with RP between 2015 and 2018. First, we compared ISUP GG concordance rates and the percentages of undetected clinically significant prostate cancer (csPCa: ISUP GG  ≥ 3), between TB vs. SB and RP. Second, multivariable logistic regression models tested predictors of concordance rates before and after 1:3 propensity score (PS) matching. Third, among TB patients, univariable logistic regression models tested variables associated with ISUP GG concordance at RP.

RESULTS

Overall, ISUP GG concordance rates were, respectively, 55 vs. 41.4% for TB vs. SB (P = 0.02). However, no differences in concordance rates were observed in patients with biopsy ISUP GG1 (31 vs. 33.9% for TB vs. SB; P = 0.8). Moreover, 15 vs. 18.8% csPCa were missed by TB vs. SB, respectively (P = 0.4). In multivariable logistic regression models, TB were associated with higher concordance rates before (odds ratio [OR]: 1.13; P = 0.04) and after 1:3 PS matching (OR: 1.15; P 0.03), compared to SB. In TB patients, age (OR: 0.98; P = 0.04), maximum cancer core involvement (MCCI; OR: 1.02; P = 0.02) and maximum cancer core length (MCCL; OR: 1.01; P = 0.07) were associated with ISUP GG concordance. Moreover, a trend for lower concordance rates was observed with higher PSA-D (OR: 0.77; P = 0.1). Finally, intermediate lesion location at mpMRI was associated with lowest concordance rates (44%).

CONCLUSION

In biopsy naïve patients treated with RP, TB achieved higher rates of ISUP GG concordance, but same percentages of csPCa missed, compared to SB. Moreover, only patients with ISUP GG ≥2, but not patients with ISUP GG1, exhibited higher concordance rates. Finally, age, MCCI, MCCL, PSA-D, and lesion location were associated with concordance between TB and RP.