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

Adequacy of clinical guideline recommendations for patients with low-risk cancer managed with monitoring: systematic review

OBJECTIVES

The aim of this systematic review was to summarize national and international guidelines that made recommendations for monitoring patients diagnosed with low-risk cancer. It appraised the quality of guidelines and determined whether the guidelines adequately identified patients for monitoring, specified which tests to use, defined monitoring intervals, and stated triggers for further intervention. It then assessed the evidence to support each recommendation.

STUDY DESIGN AND SETTING

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, we searched PubMed and Turning Research into Practice databases for national and international guidelines' that were written in English and developed or updated between 2012 and 2023. Quality of individual guidelines was assessed using the AGREE II tool.

RESULTS

Across the 41 published guidelines, 48 different recommendations were identified: 15 (31%) for prostate cancer, 11 (23%) for renal cancer, 6 (12.5%) for thyroid cancer, and 10 (21%) for blood cancer. The remaining 6 (12.5%) were for brain, gastrointestinal, oral cavity, bone and pheochromocytoma and paraganglioma cancer. When combining all guidelines, 48 (100%) stated which patients qualify for monitoring, 31 (65%) specified which tests to use, 25 (52%) provided recommendations for surveillance intervals, and 23 (48%) outlined triggers to initiate intervention. Across all cancer sites, there was a strong positive trend with higher levels of evidence being associated with an increased likelihood of a recommendation being specific (P = 0.001) and the evidence for intervals was based on expert opinion or other guidance.

CONCLUSION

With the exception of prostate cancer, the evidence base for monitoring low-risk cancer is weak and consequently recommendations in clinical guidelines are inconsistent. There is a lack of direct evidence to support monitoring recommendations in the literature making guideline developers reliant on expert opinion, alternative guidelines, or indirect or nonspecific evidence.

Prediction of clinically significant prostate cancer using radiomics models in real-world clinical practice: a retrospective multicenter study

PURPOSE

To develop and evaluate machine learning models based on MRI to predict clinically significant prostate cancer (csPCa) and International Society of Urological Pathology (ISUP) grade group as well as explore the potential value of radiomics models for improving the performance of radiologists for Prostate Imaging Reporting and Data System (PI-RADS) assessment.

MATERIAL AND METHODS

A total of 1616 patients from 4 tertiary care medical centers were retrospectively enrolled. PI-RADS assessments were performed by junior, senior, and expert-level radiologists. The radiomics models for predicting csPCa were built using 4 machine-learning algorithms. The PI-RADS were adjusted by the radiomics model. The relationship between the Rad-score and ISUP was evaluated by Spearman analysis.

RESULTS

The radiomics models made using the random forest algorithm yielded areas under the receiver operating characteristic curves (AUCs) of 0.874, 0.876, and 0.893 in an internal testing cohort and external testing cohorts, respectively. The AUC of the adjusted_PI-RADS was improved, and the specificity was improved at a slight sacrifice of sensitivity. The participant-level correlation showed that the Rad-score was positively correlated with ISUP in all testing cohorts (r > 0.600 and p < 0.0001).

CONCLUSIONS

This radiomics model resulted as a powerful, non-invasive auxiliary tool for accurately predicting prostate cancer aggressiveness. The radiomics model could reduce unnecessary biopsies and help improve the diagnostic performance of radiologists' PI-RADS. Yet, prospective studies are still needed to validate the radiomics models further.

CRITICAL RELEVANCE STATEMENT

The radiomics model with MRI may help to accurately screen out clinically significant prostate cancer, thereby assisting physicians in making individualized treatment plans.

KEY POINTS

• The diagnostic performance of the radiomics model using the Random Forest algorithm is comparable to the Prostate Imaging Reporting and Data System (PI-RADS) obtained by radiologists. • The performance of the adjusted Prostate Imaging Reporting and Data System (PI-RADS) was improved, which implied that the radiomics model could be a potential radiological assessment tool. • The radiomics model lowered the percentage of equivocal cases. Moreover, the Rad-scores can be used to characterize prostate cancer aggressiveness.

Contemporary Review of Multimodality Imaging of the Prostate Gland

Tissue changes and the enlargement of the prostate, whether benign or malignant, are among the most common groups of diseases that affect men and can have significant impacts on length and quality of life. The prevalence of benign prostatic hyperplasia (BPH) increases significantly with age and affects nearly all men as they grow older. Other than skin cancers, prostate cancer is the most common cancer among men in the United States. Imaging is an essential component in the diagnosis and management of these conditions. Multiple modalities are available for prostate imaging, including several novel imaging modalities that have changed the landscape of prostate imaging in recent years. This review will cover the data relating to commonly used standard-of-care prostate imaging modalities, advances in newer technologies, and newer standards that impact prostate gland imaging.

Abbreviated Versus Multiparametric Prostate MRI in Active Surveillance for Prostate-Cancer Patients: Comparison of Accuracy and Clinical Utility as a Decisional Tool

(1) Purpose: To compare the diagnostic accuracy between full multiparametric contrast-enhanced prostate MRI (mpMRI) and abbreviated dual-sequence prostate MRI (dsMRI) in men with clinically significant prostate cancer (csPCa) who were candidates for active surveillance. (2) Materials and Methods: Fifty-four patients with a diagnosis of low-risk PCa in the previous 6 months had a mpMRI scan prior to a saturation biopsy and a subsequent MRI cognitive transperineal targeted biopsy (for PI-RADS ≥ 3 lesions). The dsMRI images were obtained from the mpMRI protocol. The images were selected by a study coordinator and assigned to two readers blinded to the biopsy results (R1 and R2). Inter-reader agreement for clinically significant cancer was evaluated with Cohen's kappa. The dsMRI and mpMRI accuracy was calculated for each reader (R1 and R2). The clinical utility of the dsMRI and mpMRI was investigated with a decision-analysis model. (3) Results: The dsMRI sensitivity and specificity were 83.3%, 31.0%, 75.0%, and 23.8%, respectively, for R1 and R2. The mpMRI sensitivity and specificity were 91.7%, 31.0%, 83.3%, and 23.8%, respectively, for R1 and R2. The inter-reader agreement for the detection of csPCa was moderate (k = 0.53) and good (k = 0.63) for dsMRI and mpMRI, respectively. The AUC values for the dsMRI were 0.77 and 0.62 for the R1 and R2, respectively. The AUC values for the mpMRI were 0.79 and 0.66 for R1 and R2, respectively. No AUC differences were found between the two MRI protocols. At any risk threshold, the mpMRI showed a higher net benefit than the dsMRI for both R1 and R2. (4) Conclusions: The dsMRI and mpMRI showed similar diagnostic accuracy for csPCa in male candidates for active surveillance.

Active surveillance inclusion criteria under scrutiny in magnetic resonance imaging-guided prostate biopsy: a multicenter cohort study

BACKGROUND

Although multiparametric magnetic resonance imaging (mpMRI) is recommended for primary risk stratification and follow-up in Active Surveillance (AS), it is not part of common AS inclusion criteria. The objective was to compare AS eligibility by systematic biopsy (SB) and combined MRI-targeted (MRI-TB) and SB within real-world data using current AS guidelines.

METHODS

A retrospective multicenter study was conducted by a German prostate cancer (PCa) working group representing six tertiary referral centers and one outpatient practice. Men with PCa and at least one MRI-visible lesion according to Prostate Imaging Reporting and Data System (PI-RADS) v2 were included. Twenty different AS inclusion criteria of international guidelines were applied to calculate AS eligibility using either a SB or a combined MRI-TB and SB. Reasons for AS exclusion were assessed.

RESULTS

Of 1941 patients with PCa, per guideline, 583-1112 patients with PCa in both MRI-TB and SB were available for analysis. Using SB, a median of 22.1% (range 6.4-72.4%) were eligible for AS. Using the combined approach, a median of 15% (range 1.7-68.3%) were eligible for AS. Addition of MRI-TB led to a 32.1% reduction of suitable patients. Besides Gleason Score upgrading, the maximum number of positive cores were the most frequent exclusion criterion. Variability in MRI and biopsy protocols potentially limit the results.

CONCLUSIONS

Only a moderate number of patients with PCa can be monitored by AS to defer active treatment using current guidelines for inclusion in a real-world setting. By an additional MRI-TB, this number is markedly reduced. These results underline the need for a contemporary adjustment of AS inclusion criteria.

Unified model involving genomics, magnetic resonance imaging and prostate‐specific antigen density outperforms individual co‐variables at predicting biopsy upgrading in patients on active surveillance for low risk prostate cancer

Background

Active surveillance (AS) is the reference standard treatment for the management of low risk prostate cancer (PCa). Accurate assessment of tumor aggressiveness guides recruitment to AS programs to avoid conservative treatment of intermediate and higher risk patients. Nevertheless, underestimating the disease risk may occur in some patients recruited, with biopsy upgrading and the concomitant potential for delayed treatment.

Aim

To evaluate the accuracy of mpMRI and GPS for the prediction of biopsy upgrading during active surveillance (AS) management of prostate cancer (PCa).

Method

A retrospective analysis was performed on 144 patients recruited to AS from October 2013 to December 2020. Median follow was 4.8 (IQR 3.6, 6.3) years. Upgrading was defined as upgrading to biopsy grade group ≥2 on follow up biopsies. Cox proportional hazard regression was used to investigate the effect of PSA density (PSAD), baseline Prostate Imaging‐Reporting and Data System (PI‐RADS) v2.1 score and GPS on upgrading. Time‐to‐event outcome, defined as upgrading, was estimated using the Kaplan–Meier method with log‐rank test.

Results

Overall rate of upgrading was 31.9% (n = 46). PSAD was higher in the patients who were upgraded (0.12 vs. 0.08 ng/ml², p = .005), while no significant difference was present for median GPS in the overall cohort (overall median GPS 21; 22 upgrading vs. 20 no upgrading, p = .2044). On univariable cox proportional hazard regression analysis, the factors associated with increased risk of biopsy upgrading were PSA (HR = 1.30, CI 1.16–1.47, p = <.0001), PSAD (HR = 1.08, CI 1.05–1.12, p = <.0001) and higher PI‐RADS score (HR = 3.51, CI 1.56–7.91, p = .0024). On multivariable cox proportional hazard regression analysis, only PSAD (HR = 1.10, CI 1.06–1.14, p = <.001) and high PI‐RADS score (HR = 4.11, CI 1.79–9.44, p = .0009) were associated with upgrading. A cox regression model combining these three clinical features (PSAD ≥0.15 ng/ml² at baseline, PI‐RADS Score and GPS) yielded a concordance index of 0.71 for the prediction of upgrading.

Conclusion

In this study PSAD has higher accuracy over baseline PI‐RADS score and GPS score for the prediction of PCa upgrading during AS. However, combined use of PSAD, GPS and PI‐RADS Score yielded the highest predictive ability with a concordance index of 0.71.

Role of MRI-Based Functional Imaging in Improving the Therapeutic Index of Radiotherapy in Cancer Treatment

Advances in radiation technology, such as intensity-modulated radiation therapy (IMRT), have largely enabled a biological dose escalation of the target volume (TV) and reduce the dose to adjacent tissues or organs at risk (OARs). However, the risk of radiation-induced injury increases as more radiation dose utilized during radiation therapy (RT), which predominantly limits further increases in TV dose distribution and reduces the local control rate. Thus, the accurate target delineation is crucial. Recently, technological improvements for precise target delineation have obtained more attention in the field of RT. The addition of functional imaging to RT can provide a more accurate anatomy of the tumor and normal tissues (such as location and size), along with biological information that aids to optimize the therapeutic index (TI) of RT. In this review, we discuss the application of some common MRI-based functional imaging techniques in clinical practice. In addition, we summarize the main challenges and prospects of these imaging technologies, expecting more inspiring developments and more productive research paths in the near future.

Optimal biopsy approach for detection of clinically significant prostate cancer

Prostate cancer (PCa) diagnostic and therapeutic work-up has evolved significantly in the last decade, with pre-biopsy multiparametric MRI now widely endorsed within international guidelines. There is potential to move away from the widespread use of systematic biopsy cores and towards an individualised risk-stratified approach. However, the evidence on the optimal biopsy approach remains heterogeneous, and the aim of this review is to highlight the most relevant features following a critical assessment of the literature. The commonest biopsy approaches are via the transperineal (TP) or transrectal (TR) routes. The former is considered more advantageous due to its negligible risk of post-procedural sepsis and reduced need for antimicrobial prophylaxis; the more recent development of local anaesthetic (LA) methods now makes this approach feasible in the clinic. Beyond this, several techniques are available, including cognitive registration, MRI-Ultrasound fusion imaging and direct MRI in-bore guided biopsy. Evidence shows that performing targeted biopsies reduces the number of cores required and can achieve acceptable rates of detection whilst helping to minimise complications and reducing pathologist workloads and costs to health-care facilities. Pre-biopsy MRI has revolutionised the diagnostic pathway for PCa, and optimising the biopsy process is now a focus. Combining MR imaging, TP biopsy and a more widespread use of LA in an outpatient setting seems a reasonable solution to balance health-care costs and benefits, however, local choices are likely to depend on the expertise and experience of clinicians and on the technology available.

Utility of PSA Density in Predicting Upgraded Gleason Score in Men on Active Surveillance With Negative MRI

OBJECTIVES

To determine whether PSA density (PSAD), can sub-stratify risk of biopsy upgrade among men on active surveillance (AS) with normal baseline MRI.

METHODS

We identified a cohort of patients with low and favorable intermediate-risk prostate cancer on AS at two large academic centers from February 2013 - December 2017. Analysis was restricted to patients with GG1 cancer on initial biopsy and a negative baseline or surveillance mpMRI, defined by the absence of PI-RADS 2 or greater lesions. We assessed ability of PSA, prostate volume and PSAD to predict upgrading on confirmatory biopsy.

RESULTS

We identified 98 patients on AS with negative baseline or surveillance mpMRI. Median PSA at diagnosis was 5.8 ng/mL and median PSAD was 0.08 ng/mL/mL. Fourteen men (14.3%) experienced Gleason upgrade at confirmatory biopsy. Patients who were upgraded had higher PSA (7.9 vs 5.4 ng/mL, P = .04), PSAD (0.20 vs 0.07 ng/mL/mL, P < .001), and lower prostate volumes (42.5 vs 65.8 mL, P = .01). On multivariate analysis, PSAD was associated with pathologic upgrade (OR 2.23 per 0.1-increase, P = .007). A PSAD cutoff at 0.08 generated a NPV of 98% for detection of pathologic upgrade.

CONCLUSION

PSAD reliably discriminated the risk of Gleason upgrade at confirmatory biopsy among men with low-grade prostate cancer with negative MRI. PSAD could be clinically implemented to reduce the intensity of surveillance for a subset of patients.

Serial Molecular Profiling of Low-grade Prostate Cancer to Assess Tumor Upgrading: A Longitudinal Cohort Study

BACKGROUND

The potential for low-grade (grade group 1 [GG1]) prostate cancer (PCa) to progress to high-grade disease remains unclear.

OBJECTIVE

To interrogate the molecular and biological features of low-grade PCa serially over time.

DESIGN, SETTING, AND PARTICIPANTS

Nested longitudinal cohort study in an academic active surveillance (AS) program. Men were on AS for GG1 PCa from 2012 to 2017.

INTERVENTION

Electronic tracking and resampling of PCa using magnetic resonance imaging/ultrasound fusion biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ERG immunohistochemistry (IHC) and targeted DNA/RNA next-generation sequencing were performed on initial and repeat biopsies. Tumor clonality was assessed. Molecular data were compared between men who upgraded and those who did not upgrade to GG ≥ 2 cancer.

RESULTS AND LIMITATIONS

Sixty-six men with median age 64 yr (interquartile range [IQR], 59-69) and prostate-specific antigen 4.9 ng/mL (IQR, 3.3-6.4) underwent repeat sampling of a tracked tumor focus (median interval, 11 mo; IQR, 6-13). IHC-based ERG fusion status was concordant at initial and repeat biopsies in 63 men (95% vs expected 50%, p <  0.001), and RNAseq-based fusion and isoform expression were concordant in nine of 13 (69%) ERG+ patients, supporting focal resampling. Among 15 men who upgraded with complete data at both time points, integrated DNA/RNAseq analysis provided evidence of shared clonality in at least five cases. Such cases could reflect initial undersampling, but also support the possibility of clonal temporal progression of low-grade cancer. Our assessment was limited by sample size and use of targeted sequencing.

CONCLUSIONS

Repeat molecular assessment of low-grade tumors suggests that clonal progression could be one mechanism of upgrading. These data underscore the importance of serial tumor assessment in men pursuing AS of low-grade PCa.

PATIENT SUMMARY

We performed targeted rebiopsy and molecular testing of low-grade tumors on active surveillance. Our findings highlight the importance of periodic biopsy as a component of monitoring for cancer upgrading during surveillance.

MRI/US fusion prostate biopsy in men on active surveillance: Our experience

AIM

The upgrading or staging in men with prostate cancer (PCA) undergoing active surveillance (AS), defined as Gleason score (GS) ≥ 3+4 or more than 2 area with cancer, was investigated in our experience using the software-based fusion biopsy (FB).

METHODS

We selected from our database, composed of 620 biopsies, only men on AS according to criteria of John Hopkins Protocol (T1c, < 3 positive cores, GS = 3+3 = 6). Monitoring consisted of PSA measurement every 3 months, a clinical examination every 6 months, confirmatory FB within 6 months and then annual FB in all men. The suspicious MRI lesions were scored according to the Prostate Imaging Reporting and Data System (PI-RADS) classification version 2. FB were performed with a transrectal elastic free-hand fusion platform. The overall and clinically significant cancer detection rate was reported. Secondary, the diagnostic role of systematic biopsies was evaluated.

RESULTS

We selected 56 patients on AS with mean age 67.4 years, mean PSA 6.7 ng/ml and at least one follow-up MRI-US fusion biopsy (10 had 2 or 3 follow-up biopsies). Lesions detected by MRI were: PIRADS-2 in 5, PIRADS-3 in 28, PIRADS-4 in 18 pts and PIRADS-5 in 5 patients. In each MRI lesion, FB with 2.1 ± 1.1 cores were taken with a mean total cores of 13 ± 2.4 including the systematic cores. The overall cancer detection rate was 71% (40/56): 62% (25/40) in target core and 28% (15/40) in systematic core. The overall significant cancer detection rate was 46% (26/56): 69% (18/26) in target vs 31% (8/26) in random cores.

CONCLUSIONS

The incidence of clinical significant cancer was 46% in men starting active surveillance, but it was more than doubled using MRI/US Target Biopsy 69% (18/26) rather than random cores (31%, 8/26). However, 1/3 of disease upgrades would have been missed if only the targeted biopsies were performed. Based on our experience, MRI/US fusion target biopsy must be associated to systematic biopsies to improve detection of significant cancer, reducing the risks of misclassification.

Optimizing biopsy strategy for prostate cancer: Bayesian framework of network meta-analysis and hierarchical summary receiver operating characteristic model for diagnostic accuracy

Overdiagnosis and overtreatment are well known problems in prostate cancer (PCa). The transrectal ultrasound (TRUS) Guided biopsy (GB) as a current gold standard investigation has a low positive detection rate resulting in unnecessary biopsies. The choice of optimal biopsy strategy needs to be defined. Therefore, we undertook a Bayesian network meta analysis (NMA) and Bayesian prediction in the hierarchical summary receiver operating characteristic (HSROC) model to present a method for optimizing biopsy strategy in PCa. Twenty eight relevant studies were retrieved through online databases of EMBASE, MEDLINE, and CENTRAL up to February 2020. Markov chain Monte Carlo simulation and Surface Under the Cumulative RAnking curve were used to calculate the rank probability using odds ratio with 95% credible interval. HSROC model was used to formulate the predicted true sensitivity and specificity of each biopsy strategy. Six different PCa biopsy strategies including transrectal ultrasound GB (TRUS GB), fusion GB (FUS GB), fusion + transrectal ultrasound GB (FUS + TRUS GB), magnetic resonance imaging GB (MRI GB), transperineal ultrasound GB (TPUS GB), and contrast enhanced ultrasound GB were analyzed in this study with a total of 7584 patients. These strategies were analyzed on five outcomes including detection rate of overall PCa, clinically significant PCa, insignificant PCa, complication rate, and HSROC. The rank probability showed that the overall PCa detection rate was higher in FUS + TRUS GB, MRI GB, and FUS GB. In terms of clinically significant PCa detection, FUS + TRUS GB and FUS GB had a relatively higher clinically significant PCa detection rate, whereas TRUS GB had a relatively lower rate for clinically significant PCa detection rate. MRI GB (91% and 81%) and FUS GB (82% and 83%) had the highest predicted true sensitivity and specificity, respectively, whereas TRUS GB (62% and 83%) had a lower predicted true sensitivity and specificity. MRI GB, FUS GB, and FUS + TRUS GB were associated with lower complication rate, whereas TPUS GB and TRUS GB were more associated with higher complication rate. This NMA and HSROC model highlight the important finding that FUS + TRUS GB, FUS GB, and MRI GB were superior compared with other strategies to avoid the overdiagnosis and overtreatment of PCa. FUS GB, MRI GB, and FUS + TRUS GB had lower complication rates. These results may assist in shared decision making between patients, carers, and their surgeons.

Magnetic resonance imaging-ultrasound fusion-targeted biopsy combined with systematic 12-core ultrasound-guided biopsy improves the detection of clinically significant prostate cancer: Are we ready to abandon the systematic approach?

Background:

Multiparametric (mp) magnetic resonance imaging (MRI)–ultrasound fusion-targeted biopsy (TB) has improved the detection of clinically significant prostate cancer (csCaP) using the Prostate Imaging Reporting and Data System (PI-RADS) reporting system, leading some authors to conclude that TB can replace the 12-core systematic biopsy (SB). We compared the diagnostic performance of TB with SB at our institution.

Methods:

Eighty-three men with elevated prostate-specific antigen levels (6.6 ng/mL, interquartile range [IQR] 4.5–9.2) and abnormal mp-MRI (127 lesions, PI-RADS ≥3, median size: 1.1 cm, IQR 0.8–1.6) underwent simultaneous TB and SB. Diagnosis of any CaP (Gleason score, [GS] ≥6) and csCaP (GS ≥7) was compared using the McNemar's exact test.

Results:

SB showed higher, but not statistically significant, detection rates of any CaP and csCaP (51.8% and 34.9%) versus TB (44.6% and 28.9%) (P = 0.286 and P = 0.359, respectively). TB outperformed SB in the quantification of 56.6% CaP and detecting cancer in anterior sectors (7.2%). Compared to SB, TB missed twice the amount of any CaP and csCaP. SB alone detected 22.2% of all csCaPs and upgraded 20.6% of TB-detected CaP. SB identified cancer invisible on mp-MRI (13.7% of all CaP) or missed by TB due to a small size (<1 cm) and sampling error (7% of lesions).

Conclusion:

A combination of SB with TB remained necessary for achieving the highest cancer detection rates. Limiting prostate biopsy to TB alone can miss csCaP due to the presence of synchronous high-grade cancer invisible on MRI or failure to hit the target. TB is the best approach for anterior lesions and tumor quantification.

Multiparametric magnetic resonance imaging can exclude prostate cancer progression in patients on active surveillance: a retrospective cohort study

Objectives

To assess the ability of multiparametric MRI (mp-MRI) of the prostate to exclude prostate cancer (PCa) progression during monitoring patients on active surveillance (AS).

Methods

One hundred forty-seven consecutive patients on AS with mp-MRI (T2WI, DWI, DCE-MRI) at 3T were initially enrolled. Fifty-five received follow-up mp-MRI after a minimum interval of 12 months and subsequent targeted MR/US fusion-guided biopsy (FUS-GB) plus concurrent systematic transrectal ultrasound-guided (TRUS-GB) biopsy as reference standard. Primary endpoint was the negative predictive value (NPV) of the follow-up mp-MRI to exclude histopathologic tumor progression using PRECISE recommendations. Secondary endpoints were the positive predictive value (PPV), sensitivity, specificity, Gleason score (GS) upgrades, and comparison of biopsy method.

Results

Of 55 patients, 29 (53%) had a GS upgrade on re-biopsy. All 29 patients showed a tumor progression on follow-up mp-MRI. Fifteen of 55 patients (27%) displayed signs of tumor progression, but had stable GS on re-biopsy. None of the 11 patients (20%) without signs of progression on follow-up mp-MRI had a GS upgrade on re-biopsy. The NPV was 100%, PPV was 66%, sensitivity was 100%, and specificity 42%. FUS-GB resulted in GS upgrade significantly more often (n = 28; 51%) compared with TRUS-GB (n = 12; 22%; p < 0.001).

Conclusions

(Follow-up) Mp-MRI can reliably exclude PCa progression in patients on AS. Standard serial re-biopsies might be waived if follow-up mp-MRIs are stable. Over 60% of patients with signs of tumor progression on mp-MRI during AS had a GS upgrade on re-biopsy. Targeted re-biopsies should be performed if cancer progression or higher-grade PCa is suspected on mp-MRI.

Key Points

• None of the patients with unsuspicious mp-MRI had a GS upgrade in re-biopsy and mp-MRI might replace serial biopsies in these cases

• More than 60% of patients with mp-MRI signs of tumor progression had subsequent Gleason score (GS) upgrades

• Targeted re-biopsies should be performed in case of higher GS cancer suspicion on mp-MRI

Prediction of prostate cancer Gleason score upgrading from biopsy to radical prostatectomy using pre-biopsy multiparametric MRI PIRADS scoring system

An increase or ‘upgrade’ in Gleason Score (GS) in prostate cancer following Transrectal Ultrasound (TRUS) guided biopsies remains a significant challenge to overcome. to evaluate whether MRI has the potential to narrow the discrepancy of histopathological grades between biopsy and radical prostatectomy, three hundred and thirty men treated consecutively by laparoscopic radical prostatectomy (LRP) between July 2014 and January 2019 with localized prostate cancer were included in this study. Independent radiologists and pathologists assessed the MRI and histopathology of the biopsies and prostatectomy specimens respectively. A multivariate model was constructed using logistic regression analysis to assess the ability of MRI to predict upgrading in biopsy GS in a nomogram. A decision-analysis curve was constructed assessing impact of nomogram using different thresholds for probabilities of upgrading. PIRADS scores were obtained from MRI scans in all the included cases. In a multivariate analysis, the PIRADS v2.0 score significantly improved prediction ability of MRI scans for upgrading of biopsy GS (p = 0.001, 95% CI [0.06–0.034]), which improved the C-index of predictive nomogram significantly (0.90 vs. 0.64, p < 0.05). PIRADS v2.0 score was an independent predictor of postoperative GS upgrading and this should be taken into consideration while offering treatment options to men with localized prostate cancer.

Magnetic Resonance Imaging for the Detection of High Grade Cancer in the Canary Prostate Active Surveillance Study

PURPOSE

We investigated the ability of prostate magnetic resonance imaging to detect Gleason Grade Group 2 or greater cancer in a standardized, multi-institutional active surveillance cohort.

MATERIALS AND METHODS

We evaluated men enrolled in Canary Prostate Active Surveillance Study with Gleason Grade Group less than 2 and who underwent biopsy within 12 months of multiparametric magnetic resonance imaging. Our primary outcome was biopsy reclassification to Gleason Grade Group 2 or greater. We evaluated the performance of magnetic resonance imaging PI-RADS® score and clinical factors. Multivariable logistic regression models were fit with magnetic resonance imaging and clinical factors and used to perform receiver operating curve analyses.

RESULTS

There were 361 participants with 395 prostate magnetic resonance imaging studies with a median followup of 4.1 (IQR 2.0-7.6) years. Overall 108 (27%) biopsies showed reclassification. Defining positive magnetic resonance imaging as PI-RADS 3-5, the negative predictive value and positive predictive value for detecting Gleason Grade Group 2 or greater cancer was 83% (95% CI 76-90) and 31% (95% CI 26-37), respectively. PI-RADS was significantly associated with reclassification (PI-RADS 5 vs 1 and 2 OR 2.71, 95% CI 1.21-6.17, p=0.016) in a multivariable model but did not improve upon a model with only clinical factors (AUC 0.768 vs 0.762). In 194 fusion biopsies higher grade cancer was found in targeted cores in 21 (11%) instances, while 25 (13%) had higher grade cancer in the systematic cores.

CONCLUSIONS

This study adds the largest cohort data to the body of literature for magnetic resonance imaging in active surveillance, recommending systematic biopsy in patients with negative magnetic resonance imaging and the inclusion of systematic biopsy in patients with positive magnetic resonance imaging.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Adherence to Active Surveillance Protocols for Low-risk Prostate Cancer: Results of the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance Initiative

BACKGROUND

Active surveillance (AS) enrolment criteria and follow-up schedules for low-risk prostate cancer vary between institutions. However, uncertainty remains about adherence to these protocols.

OBJECTIVE

To determine adherence to institution-specific AS inclusion criteria and follow-up schedules within the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively assessed the data of 15 101 patients from 25 established AS cohorts worldwide between 2014 and 2016.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Adherence to individual AS inclusion criteria was rated on a five-point Likert scale ranging from poor to excellent. Nonadherence to follow-up schedules was defined as absence of repeat biopsy 1 yr after the scheduled date. Cohorts were pooled into annual and Prostate Cancer Research International: Active Surveillance (PRIAS)-based biopsy schedules, and a generalised linear mixed model was constructed to test for nonadherence.

RESULTS AND LIMITATIONS

Serum prostate-specific antigen (PSA) inclusion criteria were followed in 92%, Gleason score (GS) criteria were followed in 97%, and the number of positive biopsy cores was followed in 94% of men. Both age and tumour stage (T stage) criteria had 99% adherence overall. Pooled nonadherence rates increased over time-8%, 16%, and 34% for annual schedules and 11%, 30%, and 29% for PRIAS-based schedules at 1, 4, and 7 yr, respectively-and did not differ between biopsy schedules. A limitation is that our results do not consider the use of multiparametric magnetic resonance imaging.

CONCLUSIONS

In on-going development of evidence-based AS protocols, variable adherence to PSA and GS inclusion criteria should be considered. Repeat biopsy adherence reduces with increased duration of surveillance, independent of biopsy frequency. This emphasises the importance of risk stratification at the commencement of AS.

PATIENT SUMMARY

We studied adherence to active surveillance protocols for prostate cancer worldwide. We found that inclusion criteria were generally followed well, but adherence to repeat biopsy reduced with time. This should be considered when optimising future active surveillance protocols.

MRI-Based Prostate-Specific Antigen Density Predicts Gleason Score Upgrade in an Active Surveillance Cohort

OBJECTIVE. Elevated prostate-specific antigen density (PSAD) based on transrectal ultrasound (TRUS) measurements has been shown to be strongly associated with clinically significant disease and to predict progression on active surveillance (AS) for men with disease that is at a low stage or grade. We hypothesized that elevated MRI PSAD is similarly associated with increased risk of progression on subsequent biopsy. MATERIALS AND METHODS. In this retrospective study, men with Gleason score of 3+3 on diagnostic TRUS-guided biopsy who were managed with AS, had undergone MRI, and had at least one additional biopsy were included. MRI PSAD was calculated using prostate volume on MRI and prostate-specific antigen level temporally closest to the MRI. Multivariable logistics regression models were used to evaluate the association between MRI PSAD and predictors of upgrade on serial biopsy. RESULTS. A total of 166 patients were identified, of whom 74 (44.6%) were upgraded to a Gleason score of 7 or higher on subsequent biopsy. Lesions with Prostate Imaging Reporting and Data System (PI-RADS) scores of 4 and 5 more commonly had MRI PSAD of 0.15 ng/mL² or higher (51.93% vs 22.22%, p = 0.01) than lesions with PI-RADS scores of 1-3. Median MRI PSAD was significantly higher in the upgraded group compared with the group that was not upgraded (0.15 ng/mL² vs 0.11 ng/mL², p = 0.01). MRI PSAD was significantly associated with increased odds of upgrading on subsequent biopsy (log transformation; odds ratio, 1.9 [95% CI, 1.2-2.8]; p = 0.01) after adjusting for age and length of follow-up. CONCLUSION. MRI PSAD was significantly associated with Gleason score upgrading on subsequent biopsy for men initially diagnosed with Gleason 3+3 disease. Although this result is intuitive, to our knowledge it has not been previously shown. As MRI utilization increases, MRI PSAD can aid in risk stratification for men managed with AS.

Can the addition of clinical information improve the accuracy of PI-RADS version 2 for the diagnosis of clinically significant prostate cancer in positive MRI?

AIM

To report prostate cancer (PCa) prevalence in Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) categories and investigate the potential to avoid unnecessary, magnetic resonance imaging (MRI)-guided in-bore biopsies by adding clinical and biochemical patient characteristics.

MATERIALS AND METHODS

The present institutional review board-approved, prospective study on 137 consecutive men with 178 suspicious lesions on 3 T MRI was performed. Routine data collected for each patient included patient characteristics (age, prostate volume), clinical background information (prostate-specific antigen [PSA] levels, PSA density), and PI-RADS v2 scores assigned in a double-reading approach.

RESULTS

Histopathological evaluation revealed a total of 93/178 PCa (52.2%). The mean age was 66.3 years and PSA density was 0.24 ng/ml² (range, 0.04-0.89 ng/ml). Clinically significant PCa (csPCa, Gleason score >6) was confirmed in 50/93 (53.8%) lesions and was significantly associated with higher PI-RADS v2 scores (p=0.0044). On logistic regression analyses, age, PSA density, and PI-RADS v2 scores contributed independently to the diagnosis of csPCa (p=7.9×10^-7, p=0.097, and p=0.024, respectively). The resulting area under the receiver operating characteristic curve (AUC) to predict csPCa was 0.76 for PI-RADS v2, 0.59 for age, and 0.67 for PSA density. The combined regression model yielded an AUC of 0.84 for the diagnosis of csPCa and was significantly superior to each single parameter (p≤0.0009, respectively). Unnecessary biopsies could have been avoided in 50% (64/128) while only 4% (2/50) of csPCa lesions would have been missed.

CONCLUSIONS

Adding age and PSA density to PI-RADS v2 scores improves the diagnostic accuracy for csPCa. A combination of these variables with PI-RADS v2 can help to avoid unnecessary in-bore biopsies while still detecting the majority of csPCa.

Prostate biopsy: guidelines and evidence

PURPOSE OF REVIEW

To summarize the highest level evidence that was acquired within the last years, with regard to diagnosis of prostate cancer. With many secondary diagnostic tools becoming available, and not being mentioned in the guidelines, this review is meant to assist clinical decision-making in initial biopsy and rebiopsy settings.

RECENT FINDINGS

The PROMIS Trial delivered level 1b evidence about the diagnostic accuracy of prostate multiparametric MRI (mpMRI) as a triage tool for prostate biopsy. MRI-ultrasound-fusions-targeted biopsy has been evaluated and compared with the standard of care, and has been found to have a higher cancer detection rate. The different approaches to MRI-guided biopsies do not show significant differences. Urine biomarkers analysing RNA as well as genetic assays of biopsy specimen have also shown to be helpful in the decision to (re-)biopsy a patient, especially in combination with MRI.

SUMMARY

Patients and doctors alike have been trying to avoid prostate biopsies, the risks, and the side effects of potential overtreatment. Imaging and other biomarkers are used to increase diagnostic accuracy, yielding more precise information to act on. None of these secondary diagnostic tools are perfect, yet they can, and should be used if one stays aware of their limitations.

Standardized Magnetic Resonance Imaging Reporting Using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Criteria and Magnetic Resonance Imaging/Transrectal Ultrasound Fusion with Transperineal Saturation Biopsy to Select Men on Active Surveillance

BACKGROUND

Contemporary selection criteria for men with prostate cancer (PC) suitable for active surveillance (AS) are unsatisfactory, leading to high disqualification rates based on tumor misclassification. Conventional biopsy protocols are based on standard 12-core transrectal ultrasound (TRUS) biopsy.

OBJECTIVE

To assess the value of magnetic resonance imaging (MRI)/TRUS fusion biopsy over 4-yr follow-up in men on AS for low-risk PC.

DESIGN, SETTING, AND PARTICIPANTS

Between 2010 and 2018, a total of 273 men were included. Of them, 157 men with initial 12-core TRUS biopsy and 116 with initial MRI/TRUS fusion biopsy were followed by systematic and targeted transperineal MRI/TRUS fusion biopsies based on Prostate Cancer Research International Active Surveillance criteria. MRI from follow-up MRI/TRUS fusion biopsy was assessed using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scoring system.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

AS-disqualification rates for patients on AS initially diagnosed by either 12-core TRUS biopsy or by MRI/TRUS fusion biopsy were compared using Kaplan-Meier estimates, log-rank tests, and regression analyses. We also analyzed the influence of negative primary MRI and PRECISE scoring to predict AS disqualification using Kaplan-Meier estimates, log-rank tests, and receiver operating characteristic (ROC) curve analysis.

RESULTS AND LIMITATIONS

Of men diagnosed by 12-core TRUS biopsy, 59% were disqualified from AS based on the results of subsequent MRI/TRUS fusion biopsy. In the initial MRI fusion biopsy cohort, upgrading occurred significantly less frequently (19%, p<0.001). ROC curve analyses demonstrated good discrimination for the PRECISE score with an area under the curve of 0.83. No men with a PRECISE score of 1 or 2 (demonstrating absence or downgrading of lesions in follow-up MRI) were disqualified from AS. In our cohort, a negative baseline MRI scan was not a predictor of nondisqualification from AS. Limitations include transperineal approach and extended systematic biopsies used with MRI/TRUS fusion biopsy, which may not be representative of other centers.

CONCLUSIONS

MRI/TRUS fusion biopsies allow a reliable risk classification for patients who are candidates for AS. The application of the PRECISE scoring system demonstrated good discrimination.

PATIENT SUMMARY

In this study, we investigated the value of multiparametric magnetic resonance imaging (MRI) and MRI/transrectal ultrasound (TRUS) fusion biopsies for the assessment of active surveillance (AS) reliability using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation criteria. Standard TRUS biopsies lead to significant underestimation of prostate cancer. In contrast, MRI/TRUS fusion biopsies allowed for a more reliable risk classification. For appropriate inclusion into AS, men should receive either an initial or a confirmatory MRI/TRUS fusion biopsy.

[Active surveillance of prostate cancer : An update]

Prostate cancer is a heterogeneous disease. In cases of low-risk prostate cancer, active surveillance represents an attractive alternative treatment. Significant complications of a definitive treatment can therefore be delayed or completely avoided. Despite strict inclusion criteria for active surveillance, the diagnosis of low-risk prostate cancer can be inaccurate and there is therefore a risk of missing the optimal point in time for definitive treatment. Multimodal diagnostics and continuous aftercare are therefore crucial.

PTEN status assessment in the Johns Hopkins active surveillance cohort

BACKGROUND

Up to half of men with Gleason score 6 (GS6) prostate cancers initially managed with active surveillance (AS) will eventually require definitive therapy, usually due to tumor grade reclassification during follow-up. We examined the association between PTEN status on biopsy and subsequent clinicopathologic outcomes in men with GS6 cancers who enrolled in AS.

METHODS

We performed a case-control study of men enrolled in the Johns Hopkins AS cohort with diagnostic biopsy tissue available for immunohistochemical (IHC) staining. IHC was performed for PTEN using genetically validated protocols for all patients. Cases included men who underwent grade reclassification to GS ≥ 3 + 4 = 7 on biopsy within 2 years of follow-up (i.e., early reclassification) or reclassification to GS ≥ 4 + 3 = 7 on biopsy or radical prostatectomy during follow-up (i.e., extreme reclassification). Control patients were diagnosed with GS6 cancer and monitored on AS for at least 8 years without undergoing biopsy reclassification.

RESULTS

Among 67 cases with adequate tissue, 31 men underwent early reclassification and 36 men underwent extreme reclassification. Cases were compared to 65 control patients with adequate tissue for assessment. On initial prostate biopsy, cases were older (median age 67 vs. 65, p = 0.024) and were less likely to meet very-low-risk criteria (64 vs 79%, p = 0.042) as compared to controls. Although not statistically significant, PTEN loss was observed in only 1 (1.5%) of 65 controls as compared to 6 (9%) of 67 cases (p = 0.062).

CONCLUSIONS

PTEN loss was rare among men with GS6 prostate cancer enrolled in AS at Johns Hopkins. Despite this, PTEN loss was more frequent among men who underwent early or extreme reclassification to higher-grade cancer as compared to controls. Additional studies in larger low-risk cohorts may better elucidate a potential role for PTEN in selecting patients for AS.

Temporary Health Impact of Prostate MRI and Transrectal Prostate Biopsy in Active Surveillance Prostate Cancer Patients

PURPOSE

To assess the temporary health impact of prostate multiparametric MRI (mpMRI) and transrectal prostate biopsy in an active surveillance prostate cancer population.

METHODS

A two-arm institutional review board-approved HIPAA-compliant prospective observational patient-reported outcomes study was performed from November 2017 to July 2018. Inclusion criteria were men with Gleason 6 prostate cancer in active surveillance undergoing either prostate mpMRI or transrectal prostate biopsy. A survey instrument was constructed using validated metrics in consultation with the local patient- and family-centered care organization. Study subjects were recruited at the time of diagnostic testing and completed the instrument by phone 24 to 72 hours after testing. The primary outcome measure was summary testing-related quality of life (summary utility score), derived from the testing morbidities index (TMI) (scale: 0 = death and 1 = perfect health). TMI is stratified into seven domains, with each domain scored from 1 (no health impact) to 5 (extreme health impact). Testing-related quality-of-life measures in the two cohorts were compared with Mann-Whitney U test.

RESULTS

In all, 122 subjects were recruited, and 90% (110 of 122 [MRI 55 of 60, biopsy 55 of 62]) successfully completed the survey instrument. The temporary quality-of-life impact of transrectal biopsy was significantly greater than that of prostate mpMRI (0.82, 95% confidence interval [CI] 0.79-0.85, versus 0.95, 95% CI 0.94-0.97; P < .001). The largest mean domain-level difference was for intraprocedural pain (transrectal biopsy 2.6, 95% CI 2.4-2.8, versus mpMRI 1.3, 95% CI 1.1-1.5; P < .001).

CONCLUSION

Transrectal prostate biopsy has greater temporary health impact (lower testing-related quality-of-life measure) than prostate mpMRI.

MRI findings guiding selection of active surveillance for prostate cancer: a review of emerging evidence

Active surveillance (AS) for prostate cancer (PCa) is generally considered to be a safe strategy for men with low-risk, localized disease. However, as many as 1 in 4 patients may be incorrectly classified as AS-eligible using traditional inclusion criteria. The use of multiparametric magnetic resonance imaging (mpMRI) may offer improved risk stratification in both the initial diagnostic and disease monitoring setting. We performed a review of recently published studies to evaluate the utility of this imaging modality for this clinical setting. An English literature search was conducted on PubMed for original investigations on localized PCa, AS, and magnetic resonance imaging. Our Boolean criteria included the following terms: PCa, AS, imaging, MRI, mpMRI, prospective, retrospective, and comparative. Our search excluded publication types such as comments, editorials, guidelines, reviews, or interviews. Our literature review identified 71 original investigations. Among these, 52 met our inclusion criteria. Evidence suggests mpMRI improves characterization of clinically significant prostate cancer (csPCa) foci, and the enhanced detection and risk-stratification afforded by this modality may keep men from being inappropriately placed on AS. Use of serial mpMRI may also permit longer intervals between confirmatory biopsies. Multiple studies demonstrate the benefit of MRI-targeted biopsies. The use of mpMRI of the prostate offers improved confidence in risk-stratification for men with clinically low-risk PCa considering AS. While on AS, serial mpMRI and MRI-targeted biopsy aid in the detection of aggressive disease transformation or foci of clinically-significant cancer undetected on prior biopsy sessions.

MRI in active surveillance: a critical review

INTRODUCTION

Recent technological advancements and the introduction of modern anatomical and functional sequences have led to a growing role for multiparametric magnetic resonance imaging (mpMRI) in the detection, risk assessment and monitoring of early prostate cancer. This includes men who have been diagnosed with lower-risk prostate cancer and are looking at the option of active surveillance (AS). The purpose of this paper is to review the recent evidence supporting the use of mpMRI at different time points in AS, as well as to discuss some of its potential pitfalls.

METHODS

A combination of electronic and manual searching methods were used to identify recent, important papers investigating the role of mpMRI in AS.

RESULTS

The high negative predictive value of mpMRI can be exploited for the selection of AS candidates. In addition, mpMRI can be efficiently used to detect higher risk disease in patients already on surveillance.

CONCLUSION

Although there is an ongoing debate regarding the precise nature of its optimal implementation, mpMRI is a promising risk stratification tool and should be considered for men on AS.

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Is magnetic resonance imaging-targeted biopsy a useful addition to systematic confirmatory biopsy in men on active surveillance for low-risk prostate cancer? A systematic review and meta-analysis

OBJECTIVE

To systematically review and meta-analyse evidence regarding the additional value of magnetic resonance imaging (MRI) and MRI-targeted biopsies to confirmatory systematic biopsies in identifying high-grade prostate cancer in men with low-risk disease on transrectal ultrasonography (TRUS) biopsy, as active surveillance (AS) of prostate cancer is recommended for men with Gleason 3 + 3 on standard TRUS-guided biopsy. Confirmatory assessment can include repeat standard TRUS-guided biopsy, and/or MRI with targeted biopsy when indicated.

METHODS

A systematic review of the Embase, Medline, Web-of-science, Google scholar, and Cochrane library was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Identified reports were critically appraised according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 criteria. Studies reporting men with Gleason 3 + 3 prostate cancer who had chosen AS based on transrectal systematic biopsy findings and had undergone MRI with systematic ± targeted biopsy at confirmatory assessment were included. The primary outcome was detection of any Gleason pattern ≥4.

RESULTS

Included reports (six) of men on AS (n = 1 159) showed cancer upgrading (Gleason ≥3 + 4) in 27% (95% confidence interval [CI] 22-34%) using a combined approach of MRI-targeted biopsies and confirmatory systematic biopsies. MRI-targeted biopsies alone would have missed cancer upgrading in 10% (95% CI 8-14%) and standard biopsies alone would have missed cancer upgrading in 7% (95% CI 5-10%). No pathway was more favourable than the other (relative risk [RR] 0.92, 95% CI 0.79-1.06). In all, 35% (95% CI 27-43%) of men with a positive MRI were upgraded, compared to 12% (95% CI 8-18%) of men with a negative MRI being upgraded (RR 2.77, 95% CI 1.76-4.38).

CONCLUSIONS

A pre-biopsy MRI should be performed before confirmatory systematic TRUS-guided biopsies in men on AS, together with MRI-targeted biopsies when indicated. A combined approach maximises cancer detection, although other factors within multivariate risk prediction can be used to aid the decision to biopsy in these men.

Integration and Diagnostic Accuracy of 3T Nonendorectal coil Prostate Magnetic Resonance Imaging in the Context of Active Surveillance

OBJECTIVE

To evaluate the integration of 3T nonendorectal coil multiparametric prostate magnetic resonance imaging (mpMRI) at 2 high-volume practices that routinely use mpMRI in the setting of active surveillance.

MATERIALS AND METHODS

This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, and dual-institution retrospective cohort study. Subjects undergoing 3T mpMRI without endorectal coil at either study institution over a 13-month period (August 1, 2015-August 31, 2016) were selected based on predefined criteria: clinical T1/T2 Gleason 6 prostate cancer, prostate-specific antigen <15 ng/mL, ≥40 years old, mpMRI within 2 years of prostate biopsy, and Prostate Imaging Reporting and Data System (PI-RADS) v2 score assigned. Subjects surveilled for Gleason ≥3 + 4 prostate cancer were excluded. The primary outcome was detection of Gleason ≥3 + 4 prostate cancer on magnetic resonance-ultrasound fusion biopsy, standard biopsy, or prostatectomy within 6 months following mpMRI. Positive predictive values (PPVs) were calculated.

RESULTS

A total of 286 subjects (N = 193 from institution 1, N = 93 from institution 2) met the criteria. Most (87% [90 of 104]) with maximum PI-RADS v2 scores of 1-2 did not receive immediate biopsy or treatment and remained on active surveillance. Incidence and PPVs for PI-RADS v2 scores of ≥3 were the following: PI-RADS 3 (n = 57 [20%], PPV 21% [6 of 29]), PI-RADS 4 (n = 96 [34%], PPV 51% [39 of 77]), and PI-RADS 5 (n = 29 [13%], PPV 71% [20 of 28]). No Gleason ≥4 + 3 prostate cancer was identified for PI-RADS v2 scores of 1-3 (0 of 43 with histology). Following mpMRI and subsequent biopsy, 21% (61 of 286) of subjects were removed from active surveillance and underwent definitive therapy.

CONCLUSION

The 3T nonendorectal coil mpMRI has been integrated into the care of patients on active surveillance and effectively stratifies risk of Gleason ≥3 + 4 prostate cancer in this population.

In-bore MRI-guided biopsy: can it optimize the need for periodic biopsies in prostate cancer patients undergoing active surveillance? A pilot test-retest reliability study

OBJECTIVE

To evaluate the test-retest reliability of repeated in-bore MRI-guided prostate biopsy (MRGB).

METHODS

19 lesions in 7 patients who had consecutive MRGBs were retrospectively analysed. Five patients had 2 consecutive MRGBs and two patients had 3 consecutive MRGBs. Both multiparametric MRI and MRGBs were performed using a 3T MRI scanner. Pathology results were categorized into benign, suspicious and malignant. Consistency between first and subsequent biopsy results were analysed as well as the negative predictive value (NPV) for prostate cancer.

RESULTS

15 lesions (≈79%) had matching second biopsy and 4 (21%) had non-matching second biopsy. Lesions with both Prostate Imaging - Reporting and Data System(PIRADS) categories 1 and 4 were all benign and had matching pathology results. Lesions with non-matching results had PIRADS categories 2, 3 and 5. NPV for prostate cancer in first biopsy was 87.5%. Overall agreement was 78.9% and overall disagreement was 21.1%.κ = 0.55 denoting moderate agreement (p = 0.002). 10/19 lesions had a third biopsy session. 9/10 (90%) had matching pathology results across the three biopsy sessions and all matching lesions were benign.

CONCLUSION

In-bore MRI-guided prostate biopsy may have a better reliability for repeat biopsies compared to TRUS biopsy. Final conclusion awaits a prospective analysis on a larger cohort of patients. Advances in knowledge: This pilot study showed that repeated prostate in-bore MRI-guided prostate biopsy may have better reliability compared to TRUS biopsy with a suggested high NPV.

Reduction of MRI-targeted biopsies in men with low-risk prostate cancer on active surveillance by stratifying to PI-RADS and PSA-density, with different thresholds for significant disease

Background

The fear of undergrading prostate cancer (PCa) in men on active surveillance (AS) have led to strict criteria for monitoring, which have resulted in good long-term cancer-specific survival, proving the safety of this approach. Reducing undergrading, MRI-targeted biopsies are increasingly used in men with low-risk disease despite their undefined role yet. The objective of this study is to investigate the rate of upgrading using MRI-targeted biopsies in men with low-risk disease on AS, stratified on the basis of PI-RADS and PSA-density, with the aim to reduce potential unnecessary repeat biopsy procedures.

Methods

A total of 331 men were prospectively enrolled following the MRI-PRIAS protocol. MR imaging was according to Prostate Imaging Reporting and Data System (PI-RADSv2) guidelines. Suspicious MRI lesions (PI-RADS 3–5) were additionally targeted by MRI-TRUS fusion biopsies. Outcome measure was upgrading to Gleason score (GS) ≥3+4 with MRI-targeted biopsies, stratified for PI-RADS and PSA-density.

Results

In total, 25% (82/331) of men on AS showed upgrading from GS 3+3. Only 3% (11/331) was upgraded to GS ≥8. In 60% (198/331) a suspicious MRI lesion was identified, but in only 41% (82/198) of men upgrading was confirmed. PI-RADS 3, 4 and 5 categorized index lesions, showed upgrading in 30%, 34% and 66% of men, respectively. Stratification to PI-RADS 4–5, instead of PI-RADS 3–5, would have missed a small number of high volume Gleason 4 PCa in PI-RADS 3 category. However, further stratification into PI-RADS 3 lesions and PSA-density <0.15 ng/mL² could result in a safe targeted biopsy reduction of 36% in this category, without missing any upgrades.

Conclusions

Stratification with the combination of PI-RADS and PSA-density may reduce unnecessary additional MRI biopsy testing. Overall, the high rate of detected upgrading in men on AS may result in an unintended tightening of continuing in AS. Since patients, included under current AS criteria showed extremely favorable outcome, there might be no need to further restrict continuing on AS with MRI and targeted biopsies.

Localized prostate cancer and robot-assisted laparoscopic radical prostatectomy: a retrospective, comparative study between pre- and post-operative Gleason scores

INTRODUCTION

To compare the pre- and post-operative Gleason scores (GS) in patients with localized prostate cancer treated with robot-assisted laparoscopic radical prostatectomy.

MATERIALS AND METHODS

A single center, retrospective comparison between pre- and post-operative GS. Age, prostate volume, PSA, number of biopsies, number of positive cores, biopsy GS, cTNM, final pathology GS and pTNM of 286 patients were retrieved. They were divided into risk groups.

RESULTS

A total of 286 patients with a mean age at surgery of 64.64 ± 7.81 y and mean PSA-value of 9.35 ± 8.38 ng/mL. Mean prostate volume was 55.09 ± 24.93 mL, mean number of biopsies was 11.90 ± 4.63. Mean percentage of positive cores was 36.90 ± 22.42%. A GS of <7 was seen in 23.4%, 66.8% had a GS of 7 and 9.7% of >7 in final pathology. Of the total, 38.1% were pre-operative low risk, 58.7% of them had an upgrade in GS on final pathology, 45.1% were in the intermediate risk group, 5.4% showed a downgrade, 64.3% remained stable and 30.2% had an upgrade in GS. Also, 16.8% were high risk patients of which 35.4% had a downgrade, 39.6% remained stable and 25% showed an upgrade of the GS.

CONCLUSIONS

We found a substantial underestimation of the GS in the pre-operative setting when compared to the GS in final pathology.

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.

[Prostate cancer diagnostic by saturation randomized biopsy versus rigid targeted biopsy]

INTRODUCTION

Optimal diagram teaming up randomized biopsy (BR) to targeted biopsy (BC) is still missing for the diagnostic of prostate cancer (CP). This study compares diagram of 6, 12 or 18 BR with or without BC rigid.

METHODS

Between January 2014 and May 2016, 120 patients had prostate biopsy BR and BC. Each patient had 18 BR and BC. Results compared sextant (6 BR), standard (12 BR) and saturation (18 BR) protocol with or without the adding of BC for the detection of CP.

RESULTS

Rectal examination was normal, mean PSA at 8.99ng/mL and mean volume at 54cm³. It was first round for 48% of patients. Forty-four cancers were found by the group 18 BR+BC (control). The detection rate was respectively, for 6, 12 and 18 BR of 61%, 82% and 91%. The add of BC increased this detection of +27% for 6 BR+BC, +13% for 12 BR+BC and +9% for 18 BR+BC. BC found 70% of all CP. Nine percent of CP were missed by BR only. Significant CP (Gleason≥7) diagnostic was the same for 12 BR+BC and 18 BR+BC.

CONCLUSION

The add of BC to BR increase the detection of CP by 10%. Twelve BR+BC is the optimal diagram for the diagnostic of CP finding 95% of CP and 97% of significant CP.

LEVEL OF EVIDENCE

4.

Prostate Cancer Imaging and Biomarkers Guiding Safe Selection of Active Surveillance

Background

Active surveillance (AS) is a widely adopted strategy to monitor men with low-risk, localized prostate cancer (PCa). Current AS inclusion criteria may misclassify as many as one in four patients. The advent of multiparametric magnetic resonance imaging (mpMRI) and novel PCa biomarkers may offer improved risk stratification. We performed a review of recently published literature to characterize emerging evidence in support of these novel modalities.

Methods

An English literature search was conducted on PubMed for available original investigations on localized PCa, AS, imaging, and biomarkers published within the past 3 years. Our Boolean criteria included the following terms: PCa, AS, imaging, biomarker, genetic, genomic, prospective, retrospective, and comparative. The bibliographies and diagnostic modalities of the identified studies were used to expand our search.

Results

Our review identified 222 original studies. Our expanded search yielded 244 studies. Among these, 70 met our inclusion criteria. Evidence suggests mpMRI offers improved detection of clinically significant PCa, and MRI-fusion technology enhances the sensitivity of surveillance biopsies. Multiple studies demonstrate the promise of commercially available screening assays for prediction of AS failure, and several novel biomarkers show promise in this setting.

Conclusion

In the era of AS for men with low-risk PCa, improved strategies for proper stratification are needed. mpMRI has dramatically enhanced the detection of clinically significant PCa. The advent of novel biomarkers for prediction of aggressive disease and AS failure has shown some initial promise, but further validation is warranted.

Preventing clinical progression and need for treatment in patients on active surveillance for prostate cancer

PURPOSE OF REVIEW

Active surveillance is an established treatment option for men with localized, low-risk prostate cancer (CaP). It entails the postponement of immediate therapy with the option of delayed intervention upon disease progression. The rate of clinical progression and need for treatment on active surveillance is approximately 50% over 15 years. The present review summarizes recent data on current methods, attempting to prevent clinical progression.

RECENT FINDINGS

Patient selection for active surveillance is the first mandatory step required to lower progression. Adherence to active surveillance protocols is critical in making sure patients are monitored well and treated early when progression occurs. Before active surveillance allocation and during active surveillance follow-up, methods involving multiparametric MRI, prostate specific antigen derivatives, biopsy factors, urinary, tissue and genetic markers can be used to prevent clinical progression and/or identify those at risk for progression. Medications such as 5α-reductase inhibitors and others might inhibit disease progression in patients on active surveillance.

SUMMARY

Active surveillance is required because of overdiagnosis, along with our inability to accurately predict individual CaP behavior. Several methods can potentially reduce the risk of CaP progression in patients with active surveillance. However, a measure of uncertainty and fear of progression will always accompany patients with active surveillance and the physicians treating them.

The role of whole-lesion apparent diffusion coefficient analysis for predicting outcomes of prostate cancer patients on active surveillance

PURPOSE

To explore the role of whole-lesion apparent diffusion coefficient (ADC) analysis for predicting outcomes in prostate cancer patients on active surveillance.

METHODS

This study included 72 prostate cancer patients who underwent MRI-ultrasound fusion-targeted biopsy at the initiation of active surveillance, had a visible MRI lesion in the region of tumor on biopsy, and underwent 3T baseline and follow-up MRI examinations separated by at least one year. Thirty of the patients also underwent an additional MRI-ultrasound fusion-targeted biopsy after the follow-up MRI. Whole-lesion ADC metrics and lesion volumes were computed from 3D whole-lesion volumes-of-interest placed on lesions on the baseline and follow-up ADC maps. The percent change in lesion volume on the ADC map between the serial examinations was computed. Statistical analysis included unpaired t tests, ROC analysis, and Fisher's exact test.

RESULTS

Baseline mean ADC, ADC_{0-10th-percentile}, ADC_{10-25th-percentile}, and ADC_{25-50th-percentile} were all significantly lower in lesions exhibiting ≥50% growth on the ADC map compared with remaining lesions (all P ≤ 0.007), with strongest difference between lesions with and without ≥50% growth observed for ADC_{0-10th-percentile} (585 ± 308 vs. 911 ± 336; P = 0.001). ADC_{0-10th-percentile} achieved highest performance for predicting ≥50% growth (AUC = 0.754). Mean percent change in tumor volume on the ADC map was 62.3% ± 26.9% in patients with GS ≥ 3 + 4 on follow-up biopsy compared with 3.6% ± 64.6% in remaining patients (P = 0.050).

CONCLUSION

Our preliminary results suggest a role for 3D whole-lesion ADC analysis in prostate cancer active surveillance.

Value of Tracking Biopsy in Men Undergoing Active Surveillance of Prostate Cancer

PURPOSE

We compared the upgrading rate obtained by resampling precise spots of prostate cancer (tracking biopsy) vs conventional systematic resampling during followup of men on active surveillance.

MATERIALS AND METHODS

From 2009 to 2017 in 352 men prostate cancer was Gleason 3 + 3 in 268 and Gleason 3 + 4 in 84 at initial magnetic resonance imaging-ultrasound fusion biopsy. These men subsequently underwent a second fusion biopsy. At the first biopsy session all men underwent 12-core systematic biopsies and, when magnetic resonance imaging visible lesions were present, targeted biopsies. All cancerous sites were recorded electronically. During active surveillance at a second fusion biopsy session 6 to 18 months later tracking and systematic nontracking samples were obtained. The primary outcome measure was an increase in Gleason score (upgrading) at followup sampling, which was stratified by biopsy method.

RESULTS

Overall 91 of the 352 men (25.9%) experienced upgrading at the second biopsy during a median 11-month interval. The upgrade rate in the Gleason 3 + 3 and 3 + 4 groups was 26.9% and 22.6%, respectively. The mean number of cores taken at second biopsy was 12.2 ± 3.3 in men with upgrading and 12.4 ± 4.1 in those who remained stable (p not significant). Men with grade 0 to 4 magnetic resonance imaging targets were all upgraded at approximately the same rate of 20% to 30% (p not significant). However, 58.8% of the men with grade 5 magnetic resonance imaging targets were upgraded. Of the 91 upgrades 48 (53%) were detected only by tracking.

CONCLUSIONS

The tracking function of magnetic resonance imaging-ultrasound fusion biopsy warrants further study. When specific sites are resampled in men undergoing active surveillance of prostate cancer, upgrading is detected more often than by nontracking biopsy.

[Diagnostic significance of multiparametric MRI combined with US-fusion guided biopsy of the prostate in patients with increased PSA levels and negative standard biopsy results to detect significant prostate cancer - Correlation with the Gleason score. Korrelation mit dem Gleason Score]

AIMS

To increase diagnostic precision and to reduce overtreatment of low-risk malignant disease, multiparametric MRI (mpMRI) combined with ultrasound (US) fusion guided biopsy of the prostate were performed.

METHODS

In 99 male patients with increased PSA plasma levels and previous negative standard biopsy procedures, mpMRI was carried out followed by US fusion guided perineal biopsy. PI-RADS-Data (PS) of mpMRI and histopathological Gleason score (GS) were categorized and statistically compared.

RESULTS

Lesions in 72/99 (73 %) of patients were determined to be suspect of malignancy, based on a PS 4 or 5. In 33/99 (33 %) of patients, malignancy could not be confirmed by histopathology. With regard to the remaining 66 patients with previous negative biopsy results, 42 (64 %) were diagnosed with a low-grade carcinoma (GS 6, 7a) and 24 (36 %) with a high-grade carcinoma (GS ≥ 7b). The proportion of corresponding results in mpMRI (PS 4-5) when a high-grade carcinoma had been detected, was 21/24 (88 %), which related to a sensitivity of 88 % and a negative predictive value (NPV) of 85 % (p = 0,002). In addition, 35 of 42 patients (83%), graded PS 4-5 in mpMRI, were diagnosed with low-grade carcinoma-positive (p < 0,001). Sensitivity to differentiation between low- and high-grade carcinomas (GS ≤ 7a vs. ≥ 7b) by means of PS was 88 % with a NPV of 70 % (p = 0,74).

CONCLUSION

Our results suggest that mpMRI combined with US-fusion guided biopsy is able to detect considerably higher rates of clinically relevant prostate malignancies compared to conventional diagnostic procedures. However, no statistical significance could be shown regarding the differentiation between high- and low-grade carcinomas. It is hoped that the hybrid methods PSMA-PET/CT or PSMA-PET/MRI will lead to the next optimization step in the differentiation between high- and low-grade carcinomas which so far has been unsatisfactory.

Prognostic Significance of a Negative Confirmatory Biopsy on Reclassification Among Men on Active Surveillance

OBJECTIVE

To examine the association between absence of disease on confirmatory biopsy and risk of pathologic reclassification in men on active surveillance (AS).

MATERIALS AND METHODS

Men with grade groups 1 and 2 disease on AS between 2002 and 2015 were identified who received a confirmatory biopsy within 1 year of diagnosis and ≥3 biopsies overall. The primary outcomes were pathologic reclassification by grade (any increase in primary Gleason pattern or Gleason score) or volume (>33% of sampled cores involved or increase in the number of cores with >50% involvement). The effect of a negative confirmatory biopsy survival was evaluated using Kaplan-Meier analysis and a Cox proportional hazards modeling.

RESULTS

Out of 635 men, 224 met inclusion criteria (median follow-up: 55.8 months). A total of 111 men (49.6%) had a negative confirmatory biopsy. Decreased grade reclassification (69.7% vs 83.9%; P = .01) and volume reclassification (66.3% vs 87.4%; P = .004) was seen at 5 years for men with a negative confirmatory biopsy compared with those with a positive biopsy. On adjusted analysis, a negative confirmatory biopsy was associated with a decreased risk of grade reclassification (hazard ratio, 0.51; 95% confidence interval, 0.28-0.94; P = .03) and volume reclassification (hazard ratio, 0.32; 95% confidence interval, 0.17-0.61; P = .0006) at a median of 4.7 years.

CONCLUSION

Absence of cancer on the confirmatory biopsy is associated with a significant decrease in rate of grade and volume reclassification among men on AS. This information may be used to better counsel men on AS.