Pathological upgrading and up staging with immediate repeat biopsy in patients eligible for active surveillance

Enhancing Prostate Cancer Staging: Association of 68Ga-PSMA PET/CT Imaging with Histopathological Grading in Treatment-Naive Patients

OBJECTIVE

This study aimed to evaluate the correlation between 68Ga-PSMA uptake in PSMA PET/CT in primary prostate cancer (PC) and its histopathological grading (Gleason score and ISUP grade). Additionally, we compared preoperative biopsy histopathological findings with definitive pathology results in radical prostatectomy (RP) specimens.

METHODS

We retrospectively analyzed 86 patients who underwent 68Ga-PSMA PET/CT for primary PC staging, of which 40 patients later underwent radical prostatectomy. PET/CT results, including SUVmax values, were correlated with GS and PSA concentrations. Histopathology reports were analyzed and compared between biopsy and final pathology results following RP.

RESULTS

A significant positive correlation was observed between SUVmax and ISUP grades (Pearson's ρ = 0.34, p < 0.001), with higher SUVmax values associated with more advanced grades. A cut-off SUVmax value of 5.64 was determined to predict upstaging in patients, yielding a sensitivity of 76% and a specificity of 60% (AUC = 0.82, 95% CI: 0.70-0.94). Additionally, 57.5% of patients experienced a grade shift following RP, with a 35% upgrade and 22.5% downgrade in ISUP grades.

CONCLUSION

68Ga-PSMA PET/CT demonstrated high sensitivity in detecting high-risk prostate cancer, particularly in patients with GS > 7 or PSA levels ≥ 10 ng/mL. The findings suggest that this imaging modality may be less effective for the staging of patients with lower GS or PSA values, that is, low-risk PCa. Further prospective studies are necessary to validate these results.

Has Active Surveillance for Prostate Cancer Become Safer? Lessons Learned from a Global Clinical Registry

BACKGROUND AND OBJECTIVE

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men around the world with low-risk prostate cancer (or in selected cases intermediate-risk disease). Here, we report on the safety and acceptability of AS, and treatment outcomes for low- and intermediate-risk tumours over time in 14 623 men with follow-up of over 6 yr.

METHODS

Clinical data from 26 999 men on AS from 25 cohorts in 15 countries have been collected in an international database from 2000 onwards.

KEY FINDINGS AND LIMITATIONS

Across our predefined four time periods of 4 yr each (covering the period 2000-2016), there was no significant change in overall survival (OS). However, metastasis-free survival (MFS) rates have improved since the second period and were excellent (>99%). Treatment-free survival rates for earlier periods showed a slightly more rapid shift to radical treatment. Over time, there was a constant proportion of 5% of men for whom anxiety was registered as the reason for treatment alteration. There was, however, also a subset of 10-15% in whom treatment was changed, for which no apparent reason was available. In a subset of men (10-15%), tumour progression was the trigger for treatment. In men who opted for radical treatment, surgery was the most common treatment modality. In those men who underwent radical treatment, 90% were free from biochemical recurrence at 5 yr after treatment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our study confirms that AS was a safe management option over the full duration in this large multicentre cohort with long-term follow-up, given the 84.1% OS and 99.4% MFS at 10 yr. The probability of treatment at 10 yr was 20% in men with initial low-risk tumours and 31% in men with intermediate-risk tumours. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

PATIENT SUMMARY

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men with prostate cancer around the world. In this report, we show the long-term safety of following AS for men with low- and intermediate-risk prostate cancer. Our study confirms AS as a safe management option for low- and intermediate-risk prostate cancer. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

Standardised Uptake Value in Organ Confined Prostate Cancer in 68-Ga- Prostate-Specific Membrane Antigen Positron Emission Tomography-Computed Tomography Scan and its Correlation with Prostate Specific Antigen Level and Gleason Score

Introduction

A positron emission tomography (PET) scan and a computed tomography (CT) scan are an integral part of oncological imaging and other modalities such as magnetic resonance imaging, CT or bone scintigraphy have some limitations in staging the workup of prostate carcinoma. Combined with tissue-specific markers like prostate-specific membrane antigen (PSMA), positron emitter-based functional imaging results have improved. Our study aimed to determine the Standardised Uptake Value (SUVmax) in prostate adenocarcinoma that is confined to the organ in Ga-68-PSMA PET-CT scans and how it correlates with prostate-specific antigen (PSA) levels and Gleason score (GS).

Materials and Methods

This cross-sectional study was conducted at Sindh Institute of Urology and Transplantation (SIUT), Karachi, and includes subjects referred for a Ga68-PSMA PET-CT scan from September 2017 to January 2022. Histopathologic-proven adenocarcinoma prostate patients with organ-confined disease and PSA levels obtained within 6 weeks before the PSMA-PET-CT scan were included in the study. PET-CT images were semi-quantitatively analysed by measuring SUVmax and the result was interpreted using statistical software SPSS version 22.0.

Results

A total of 154 patients were analysed. The mean age of patients was 66.57 ± 8.86 years. The GS of all patients ranges from 6 to 10. The mean and median PSA levels were 32.33 ng/mL (range: 0.004-306.00) and 14.20 ng/mL, respectively. The mean SUVmax of all prostatic lesions was 14.67 ± 12.58 and the median value was 10.76. SUVmax was higher in patients with a PSA level of more than ten than those with a <10. The correlation of SUVmax with PSA and GS showed a significant correlation.

Conclusion

The SUVmax of organ-confined prostate cancer correlates well with PSA level and GS Median SUVmax and PSA directly relate to GS.

Outcomes of Grade Group 2 and 3 Prostate Cancer on Initial Versus Confirmatory Biopsy: Implications for Active Surveillance

BACKGROUND

Active surveillance (AS) is recommended as the preferred treatment for men with low-risk disease. In order to optimize risk stratification and exclude undiagnosed higher-grade disease, most AS protocols recommend a confirmatory biopsy.

OBJECTIVE

We aimed to compare outcomes among men with grade group (GG) 2/3 prostate cancer on initial biopsy with those among men whose disease was initially GG1 but was upgraded to GG2/3 on confirmatory biopsy.

DESIGN, SETTING, AND PARTICIPANTS

We reviewed patients undergoing radical prostatectomy (RP) in two cohorts: "immediate RP group," with GG2/3 cancer on diagnostic biopsy, and "AS group," with GG1 cancer on initial biopsy that was upgraded to GG2/3 on confirmatory biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Probabilities of biochemical recurrence (BCR) and salvage therapy were determined using multivariable Cox regression models with risk adjustment. Risks of adverse pathology at RP were also compared using logistic regression.

RESULTS AND LIMITATIONS

The immediate RP group comprised 4009 patients and the AS group comprised 321 patients. The AS group had lower adjusted rates of adverse pathology (27% vs 35%, p = 0.003). BCR rates were lower in the AS group, although this did not reach conventional significance (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.50-1.06, p = 0.10) compared with the immediate RP group. Risk-adjusted 1- and 5-yr BCR rates were 4.6% (95% CI 3.0-6.5%) and 10.4% (95% CI 6.9-14%), respectively, for the AS group compared with 6.3% (95% CI 5.6-7.0%) and 20% (95% CI 19-22%), respectively, in the immediate RP group. A nonsignificant association was observed for salvage treatment-free survival favoring the AS group (HR 0.67, 95% CI 0.42, 1.06, p = 0.087).

CONCLUSIONS

We found that men with GG1 cancer who were upgraded on confirmatory biopsy tend to have less aggressive disease than men with the same grade found at initial biopsy. These results must be confirmed in larger series before recommendations can be made regarding a more conservative approach in men with upgraded pathology on surveillance biopsy.

PATIENT SUMMARY

We studied men with low-risk prostate cancer who were initially eligible for active surveillance but presented with more aggressive cancer on confirmatory biopsy. We found that outcomes for these men were better than the outcomes for those diagnosed initially with more serious cancer.

Clinical and histological predictive factors of reclassification of prostate cancer patients on active surveillance

INTRODUCTION AND OBJECTIVE

Active surveillance (AS) has been established as a therapeutic strategy in patients with low-risk prostate cancer. Demographic and anatomopathological factors that increase the probability of reclassifying patients have been identified.

MATERIALS AND METHODS

Laboratory and histopathological data were collected from 116 patients included on AS since 2014. Univariate analysis was performed with Chi-square, t-student and Kendall's Tau, multivariate analysis according to logistic regression and Kaplan-Meier curves were calculated.

RESULTS

Of the 116 patients in AS, the median age at diagnosis was 66 years and the median follow-up was 13 months (2-72). Of these, 61 (52.6%) are still on surveillance, while 55 (47.4%) have left the program, mostly due to histological progression (52 patients (45.2%)); radical prostatectomy was performed in 27 (49.1%). Prostate volume (PV)≤60cc and the number of positive cylinders >1 in diagnostic biopsy (P=.05) were associated with higher reclassification rate in univariate analysis (P<.05). Multivariate analysis showed that these two variables significantly correlated with higher reclassification rate (PV 60 cc: OR 4.39, P=.04; >1 positive cylinder at diagnostic biopsy: OR 2.48, P=.03).

CONCLUSIONS

It has been shown that initial ultrasound volume and the number of positive cylinders in the diagnostic biopsy are independent risk factors for reclassification. Initial PSA, laterality of the affected cylinders and PSA density were not predictive factors of progression in our series.

Focal therapy for prostate cancer: what is really needed to move from investigational to valid therapeutic alternative?-a narrative review

Background and Objective

The most widely accepted therapeutic alternatives for men with intermediate risk prostate cancer (PCa) are mainly represented by whole gland therapies such as surgery or radiotherapy. However, these treatments can carry in some cases profound functional side effects. With the improvement of risk assessment tools and imaging modalities, in particular with the introduction of multiparametric magnetic resonance imaging of the prostate, a fine topographic characterisation of PCa lesions within the prostatic gland is now possible. This has allowed the development of gland-sparing therapies such as focal therapy (FT) as a means to provide an even more tailored approach in order to safely reduce, where feasible, the harms carried by whole gland therapies. Unfortunately, adoption of FT has been considered so far investigational due to some unsolved issues that currently hamper the use of FT as a valid alternative. Here, we aim to identify the main aspects needed to move FT forward from investigational to a valid therapeutic alternative for clinically localized PCa.

Methods

The literature discussing the evolution of focal therapy in the years and its current landscape was broadly searched to identify the factors hindering FT adoption and possible solutions.

Key Content and Findings

There are three broad areas hindering FT as a valid therapeutic alternative: (I) Correct patient selection; (II) harmonising the different FT technologies; (III) the lack of oncological outcomes.

Conclusions

By targeting the three aforementioned weaknesses of FT, greater adoption is expected, finally making FT a valid therapeutic alternative, potentially reshaping prostate cancer treatment and functional outcomes.

Relationship between Apparent Diffusion Coefficient Distribution and Cancer Grade in Prostate Cancer and Benign Prostatic Hyperplasia

The aim of this paper was to assess the associations between prostate cancer aggressiveness and histogram-derived apparent diffusion coefficient (ADC) parameters and determine which ADC parameters may help distinguish among stromal hyperplasia (SH), glandular hyperplasia (GH), and low-grade, intermediate-grade, and high-grade prostate cancers. The mean, median, minimum, maximum, and 10th and 25th percentile ADC values were determined from the ADC histogram and compared among two benign prostate hyperplasia (BPH) groups and three Gleason score (GS) groups. Seventy lesions were identified in 58 patients who had undergone proctectomy. Thirty-nine lesions were prostate cancers (GS 6 = 7 lesions, GS 7 = 19 lesions, GS 8 = 11 lesions, GS 9 = 2 lesions), and thirty-one lesions were BPH (SH = 15 lesions, GH = 16 lesions). There were statistically significant differences in 10th percentile and 25th percentile ADC values when comparing GS 6 to GS 7 (p < 0.05). The 10th percentile ADC values yielded the highest area under the curve (AUC). Tenth and 25th percentile ADCs can be used to more accurately differentiate lesions with GS 6 from those with GS 7 than other ADC parameters. Our data indicate that the major challenge with ADC mapping is to differentiate between SH and GS 6, and SH and GS 7.

Prostate tumor eccentricity predicts Gleason score better than prostate tumor volume

Background

Prostate tumor volume predicts biochemical recurrence, metastases, and tumor proliferation. A recent study showed that prostate tumor eccentricity (elongation or roundness) correlated with Gleason score. No studies examined the relationship among the prostate tumor's shape, volume, and potential aggressiveness.

Methods

Of the 26 patients that were analyzed, 18 had volumes >1 cc for the histology-based study, and 25 took up contrast material for the MRI portion of this study. This retrospective study quantitatively compared tumor eccentricity and volume measurements from pathology assessment sectioned wholemount prostates and multi-parametric MRI to Gleason scores. Multi-parametric MRI (T1, T2, diffusion, dynamic contrast-enhanced images) were resized, translated, and stitched to form spatially registered multi-parametric cubes. Multi-parametric signatures that characterize prostate tumors were inserted into a target detection algorithm (Adaptive Cosine Estimator, ACE). Various detection thresholds were applied to discriminate tumor from normal tissue. Pixel-based blobbing, and labeling were applied to digitized pathology slides and threshold ACE images. Tumor volumes were measured by counting voxels within the blob. Eccentricity calculation used moments of inertia from the blobs.

Results

From wholemount prostatectomy slides, fitting two sets of independent variables, prostate tumor eccentricity (largest blob eccentricity, weighted eccentricity, filtered weighted eccentricity) and tumor volume (largest blob volume, average blob volume, filtered average blob volume) to Gleason score in a multivariate analysis, yields correlation coefficient R=0.798 to 0.879 with P<0.01. The eccentricity t-statistic exceeded the volume t-statistic. Fitting histology-based total prostate tumor volume against Gleason score yields R=0.498, P=0.0098. From multi-parametric MRI, the correlation coefficient R between the Gleason score and the largest blob eccentricity for varying thresholds (0.30 to 0.55) ranged from -0.51 to -0.672 (P<0.01). For varying thresholds (0.60 to 0.80) for MRI detection, the R between the largest blob volume eccentricity against the Gleason score ranged from 0.46 to 0.50 (P<0.03). Combining tumor eccentricity and tumor volume in multivariate analysis failed to increase Gleason score prediction.

Conclusions

Prostate tumor eccentricity, determined by histology or MRI, more accurately predicted Gleason score than prostate tumor volume. Combining tumor eccentricity with volume from histology-based analysis enhanced Gleason score prediction, unlike MRI.

Outcomes of active surveillance for clinically localized prostate cancer in a middle eastern tertiary care center

BACKGROUND

The aim of our study was to evaluate the outcome of active surveillance (AS) for prostate cancer for a cohort of patients at our institution.

METHODS

A total of 43 patients with low risk prostate cancer were enrolled in an active surveillance pilot program at our institution between 2008 and 2018. Follow up protocols included: periodic prostate specific antigen (PSA), digital rectal examination (DRE), multiparametric MRI, and prostate biopsy at one year. Pertinent parameters were collected, and descriptive statistics were reported along with a subset analysis of patients that dropped out of the protocol to receive active treatment for disease progression.

RESULTS

Out of 43 eligible patients, 46.5% had a significant rise in follow up PSA. DRE was initially suspicious in 27.9% of patients, and none had any change in DRE on follow up. Initially, prostate MRIs showed PIRADS 3, 4, and 5 in 14%, 37.2%, and 11.6% respectively, while 23.2% had a negative initial MRI. 14% did not have an MRI. Upon follow up, 18.6% of patients had progression on MRI. Initial biopsies revealed that 86% were classified as WHO group 1, while 14% as WHO group 2. With regards to the follow up biopsies, 11.6% were upgraded. 20.9% of our patients had active treatment; 44.4% due to upgraded biopsy results, 22.2% due to PSA progression, 22.2% due to strong patient preference, and 11.1% due to radiologic progression.

CONCLUSIONS

For selected men with low risk prostate cancer, AS is a reasonable alternative. The decision for active treatment should be tailored upon changes in PSA, DRE, MRI, and biopsy results.

Correlation of prostate tumor eccentricity and Gleason scoring from prostatectomy and multi-parametric-magnetic resonance imaging

Background

Proliferating cancer cells interacting with their microenvironment affects a tumor's spatial shape. Elongation or roundness (eccentricity) of lung, skin, and breast cancers indicates the cancer's relative aggressiveness. Non-invasive determination of the prostate tumor's shape should provide meaningful input for prognostication and clinical management. There are currently few studies of prostate tumor shape, therefore this study examines the relationship between a prostate tumor's eccentricity, derived from spatially registered multi-parametric MRI and histology slides, and Gleason scores.

Methods

A total of 26 consecutive patients were enrolled in the study. Median patient age was 60 years (range, 49 to 75 years), median PSA was 5.8 ng/mL (range, 2.3 to 23.7 ng/mL, and median Gleason score was 7 (range, 6 to 9). Multi-parametric MRI (T1, T2, Diffusion, Dynamic Contrast Enhanced) were resampled, rescaled, translated, and stitched to form spatially registered multi-parametric cubes. Multi-parametric signatures that characterize prostate tumors were inserted into a target detection algorithm (Adaptive Cosine Estimator, ACE). Various detection thresholds were applied to discriminate tumor from normal tissue. Also, tumor shape was computed from the histology slides. Blobbing, labeling, and calculation of eccentricity using moments of inertia were applied to the multi-parametric MRI and histology slides. The eccentricity measurements were compared to the Gleason scores from 25 patients.

Results

From histology slides analysis: the correlation coefficient between the eccentricity for the largest blob and a weighted average eccentricity against the Gleason score ranged from -0.67 to -0.78 for all 18 patients whose tumor volume exceeded 1.0 cc. From multi-parametric MRI analysis: the correlation coefficient between the eccentricity for the largest blob for varying thresholds against the Gleason score ranged from -0.60 to -0.66 for all 25 patients showing contrast uptake in the Dynamic Contrast Enhancement (DCE) MRI.

Conclusions

Spherical shape prostate adenocarcinoma shows a propensity for higher Gleason score. This novel finding follows lung and breast adenocarcinomas but depart from other primary tumor types. Analysis of multi-parametric MRI can non-invasively determine the prostate tumor's morphology and add critical information for prognostication and disease management. Eccentricity of smaller tumors (<1.0 cc) from MP-MRI correlates well with Gleason score, unlike eccentricity measured using histology of wholemount prostatectomy.

The Primacy of High B-Value 3T-DWI Radiomics in the Prediction of Clinically Significant Prostate Cancer

Predicting clinically significant prostate cancer (csPCa) is crucial in PCa management. 3T-magnetic resonance (MR) systems may have a novel role in quantitative imaging and early csPCa prediction, accordingly. In this study, we develop a radiomic model for predicting csPCa based solely on native b2000 diffusion weighted imaging (DWI_b2000) and debate the effectiveness of apparent diffusion coefficient (ADC) in the same task. In total, 105 patients were retrospectively enrolled between January–November 2020, with confirmed csPCa or ncsPCa based on biopsy. DWI_b2000 and ADC images acquired with a 3T-MRI were analyzed by computing 84 local first-order radiomic features (RFs). Two predictive models were built based on DWI_b2000 and ADC, separately. Relevant RFs were selected through LASSO, a support vector machine (SVM) classifier was trained using repeated 3-fold cross validation (CV) and validated on a holdout set. The SVM models rely on a single couple of uncorrelated RFs (ρ < 0.15) selected through Wilcoxon rank-sum test (p ≤ 0.05) with Holm–Bonferroni correction. On the holdout set, while the ADC model yielded AUC = 0.76 (95% CI, 0.63–0.96), the DWI_b2000 model reached AUC = 0.84 (95% CI, 0.63–0.90), with specificity = 75%, sensitivity = 90%, and informedness = 0.65. This study establishes the primary role of 3T-DWI_b2000 in PCa quantitative analyses, whilst ADC can remain the leading sequence for detection.

Comparison of TRUS and combined MRI-targeted plus systematic prostate biopsy for the concordance between biopsy and radical prostatectomy pathology

AIM

To evaluate the accuracy in histologic grading of MRI/US image fusion biopsy by comparing conventional 12-core TRUS-Bx at radical prostatectomy specimens (RP).

METHODS

Consecutive patients diagnosed prostate cancer (127 with combination of both targeted biopsy (TBx) plus systematic biopsies (SBx) and separate patient cohort of 330 conventional TRUS-Bx without mpMRI) with a PSA level of <20 ng/mL prior to RP were included. The primary end point was the grade group concordance between biopsy and RP pathology according to biopsy technique.

RESULTS

Clinically significant prostate cancer detection was 51.2% for TRUS-Bx, 49.5% for SBx, 67% for TBx and 75.7% for TBx + SBx. Upgrading and downgrading of at least one Gleason Grade Group (GGG) was recorded in 43.3%/ 6.7% patients of the TRUS-Bx and in 20.5%/ 22% of the TBX + SBx group, respectively (all P < .001). Concordance level was detected to be significantly higher for ISUP 1 in combined TBx + SBx method compared to conventional TRUS-Bx (61.3% vs 37.9%, P = .014). In ISUP 1 exclusively, significant upgrading was seen in TRUS-Bx (62.1%) when compared to TBx (41.4%) and TBx + SBx (38.7%).

CONCLUSIONS

MRI-targeted biopsies detected more significant PCa than TRUS-Bx but, superiority in significant cancer detection appears as a result of inadvertant selective sampling of small higher grade areas. Within an otherwise low grade cancer and does not reflect accurate GGG final surgical pathology. TBx + SBx has the greatest concordance in ISUP Grade 1 with less upgrading which is utmost important for active surveillance.

Clinical experience with active surveillance protocol using regular magnetic resonance imaging instead of regular repeat biopsy for monitoring: A study at a high-volume center in Korea

Background

Here, we report the experience of a multiparameter magnetic resonance imaging (MRI)–based active surveillance (AS) protocol that did not include performing a repeat biopsy after the diagnosis of prostate cancer by prostate biopsy or transurethral resection of prostate.

Methods

From January 2010 to December 2017, we reviewed 193 patients with newly diagnosed prostate cancer who were eligible for AS. The patients were divided into AS group (n = 122) and definitive treatment group (n = 71) based on initial treatment. Disease progression was defined as a remarkable change in MRI findings. To confirm the stability of protocol, we compared the clinicopathological characteristics of patients who initially underwent radical prostatectomy (RP) (n = 58) and RP after termination of AS (n = 20).

Results

Among patients who initially selected AS (median adherence duration = 31.4 months), 70 (57.3%) subsequently changed their treatment options. Disease progression (n = 30) was the main cause for termination. No significant differences were found in the clinicopathologic characteristics at initial diagnosis and pathologic outcomes between patients who initially underwent RP and those who chose RP after termination of AS. In a comparative analysis of diagnostic methods, the patients with incidental prostate cancer by transurethral resection of prostate had higher age, lower prostate-specific antigen level and density, as well as longer AS adherence duration and follow-up duration compared with those diagnosed by prostate biopsy.

Conclusions

Our AS monitoring protocol, which depends on MRI instead of regular repeat biopsy, was feasible. Patients with incidental prostate cancer continued AS more compared with patients diagnosed by prostate biopsy.

African-American men with low-risk prostate cancer treated with radical prostatectomy in an equal-access health care system: implications for active surveillance

BACKGROUND

There is concern that African-American men (AA) with low-risk prostate cancer may present with more aggressive disease and thus may not be candidates for active surveillance (AS). However, it is uncertain if poorer outcomes are due to disparities in access to medical care rather than true biological differences.

METHODS

Observational cohort study of patients diagnosed with low-risk PC-Gleason score ≤6, clinical tumor stage ≤2A, and prostate specific antigen (PSA) level ≤10-at US Department of Veterans Affairs between January 1, 2001 and October 31, 2015 and treated with radical prostatectomy. Outcomes included upgrading to Gleason Grade Group 2 (GG2), GG ≥ 3, PSA recurrence, pathologic tumor stage ≥3, positive surgical margins, and all-cause mortality.

RESULTS

A total of 2857 men (AA: 835 White: 2022) with a median follow-up of 7.1 years. Overall, there was no significant difference between AA and White men in upgrading to GG ≥ 3 (RR = 1.18, p = 0.43), tumor stage ≥3 (RR = 0.95, p = 0.74), positive surgical margins (RR = 1.14, p = 0.20), PSA recurrence (SHR = 1.26, p = 0.06), and all-cause mortality (SHR = 1.26, p = 0.16). However, there was a significant increase in upgrading for AA to GG2 (RR = 1.49, p < 0.01).

CONCLUSIONS

There was no significant difference in most adverse pathologic outcomes between AA and White patients. However, GG2 upgrading was more common in AA men. The implication is that AA may need to undergo additional evaluation, such as a biopsy MRI, before initiating AS. Whether the increase in GG2 upgrading will lead to poorer long-term clinical outcomes such as metastasis and PCSM also requires further investigation.

Association Between African American Race and Clinical Outcomes in Men Treated for Low-Risk Prostate Cancer With Active Surveillance

Importance

There is concern that African American men with low-risk prostate cancer may harbor more aggressive disease than non-Hispanic White men. Therefore, it is unclear whether active surveillance is a safe option for African American men.

Objective

To compare clinical outcomes of African American and non-Hispanic White men with low-risk prostate cancer managed with active surveillance.

Design, Setting, and Participants

Retrospective cohort study in the US Veterans Health Administration Health Care System of African American and non-Hispanic White men diagnosed with low-risk prostate cancer between January 1, 2001, and December 31, 2015, and managed with active surveillance. The date of final follow-up was March 31, 2020.

Exposures

Active surveillance was defined as no definitive treatment within the first year of diagnosis and at least 1 additional surveillance biopsy.

Main Outcomes and Measures

Progression to at least intermediate-risk, definitive treatment, metastasis, prostate cancer-specific mortality, and all-cause mortality.

Results

The cohort included 8726 men, including 2280 African American men (26.1%) (median age, 63.2 years) and 6446 non-Hispanic White men (73.9%) (median age, 65.5 years), and the median follow-up was 7.6 years (interquartile range, 5.7-9.9; range, 0.2-19.2). Among African American men and non-Hispanic White men, respectively, the 10-year cumulative incidence of disease progression was 59.9% vs 48.3% (difference, 11.6% [95% CI, 9.2% to 13.9%); P < .001); of receipt of definitive treatment, 54.8% vs 41.4% (difference, 13.4% [95% CI, 11.0% to 15.7%]; P < .001); of metastasis, 1.5% vs 1.4% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .49); of prostate cancer-specific mortality, 1.1% vs 1.0% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .82); and of all-cause mortality, 22.4% vs 23.5% (difference, 1.1% [95% CI, -0.9% to 3.1%]; P = 0.09).

Conclusions and Relevance

In this retrospective cohort study of men with low-risk prostate cancer followed up for a median of 7.6 years, African American men, compared with non-Hispanic White men, had a statistically significant increased 10-year cumulative incidence of disease progression and definitive treatment, but not metastasis or prostate cancer-specific mortality. Longer-term follow-up is needed to better assess the mortality risk.

Complementing the active surveillance criteria with multiparametric magnetic resonance imaging

PURPOSE

To evaluate the usefulness of multiparametric magnetic resonance imaging (mpMRI) to avoid misclassification of patients with clinically significant prostate cancer (PCa) into active surveillance (AS).

MATERIALS AND METHODS

Patients with Gleason grade group (GG) 1 PCa on systematic biopsy who underwent mpMRI before radical prostatectomy (RP) were included. mpMRI and pathologic results were compared between the AS and NOT-AS candidates. Unfavorable disease was defined as the identification of T3-4 disease or GG upgrade in the RP specimen. We established an ideal cutoff Prostate Imaging Reporting and Data System (PI-RADS) score for predicting unfavorable disease, and analyzed the location of index lesions on mpMRI.

RESULTS

PI-RADS scores were not significantly different between AS candidates (n=64) and NOT-AS candidates (n=136; p=0.629). Among 64 AS candidates, GG upgrading and unfavorable disease were diagnosed after RP in 24 (37.5%) and 25 (39.1%) patients, respectively. The rate of unfavorable disease was greater for patients with a PI-RADS score of 5 (83.3%) than in those with a score ≤4 (34.5%; p=0.030). Moreover, most PI-RADS 5 lesions in AS candidates were located in the anterior half of the prostate, with GG upgrading on targeted biopsy in 75.0% of cases.

CONCLUSIONS

Among the patients with GG 1 PCa, PI-RADS scores did not differ significantly between AS and NOT-AS candidates. Nonetheless, AS candidates with PI-RADS 5 lesions were diagnosed with unfavorable disease in >80% of RP specimens. Significant cancer located in the anterior half of the prostate including the transitional zone can be missed by systematic biopsy.

In-Bore MRI-guided Prostate Biopsies in Patients with Prior Positive Transrectal US-guided Biopsy Results: Pathologic Outcomes and Predictors of Missed Cancers

Purpose

To evaluate the role of confirmatory in-bore MRI-guided biopsy in patients with low- or intermediate-risk disease diagnosed at prior transrectal US-guided biopsy and to evaluate the rate and predictors for missed cancers.

Materials and Methods

A retrospective evaluation of 50 consecutive men who had previously undergone transrectal US-guided biopsy with positive results and who underwent subsequent in-bore MRI-guided biopsy at our university hospital (average time interval, 11 months) between 2012 and 2016 was performed. Ten men were excluded because of a history of treatment after transrectal US-guided biopsy. A total of 40 men (mean age, 63 years; range, 47-84 years) were included in this study. Multiparametric 3-T MRI (T2-weighted, diffusion-weighted, and dynamic contrast material-enhanced) and transrectal in-bore MRI-guided biopsy were performed. Cancer detection, disease-grade changes, and cancers missed at in-bore MRI-guided biopsy were evaluated. Descriptive statistics were used to report different rates. The Fisher exact test was used for categoric variables. The Mann-Whitney U test and independent Student t test were used for nonparametric and parametric data, respectively. The McNemar test was used for paired data.

Results

The overall cancer detection rate when using in-bore MRI-guided biopsy was 65% (26 of 40). In-bore MRI-guided biopsy detected 14 previously undiscovered cancerous lesions (clinically significant cancers [CSCs], 57.1% [eight of 14]). An overall disease upgrade by in-bore MRI-guided biopsy occurred in 40% (16 of 40) of cases (61.5% [16 of 26] of cases with positive results from in-bore MRI-guided biopsy). One case was downgraded from a Gleason score (GS) of 3 + 4 = 7 to a GS of 3 + 3 = 6. Out of 71 sextant biopsies with positive results detected by transrectal US-guided biopsy (from all 40 patients), 80% (57 of 71) were visible on MR images (in-bore MRI-guided biopsy results were positive in 52.6% [30 of 57]), and 20% (14 of 71) had no image correlates on MR images. In-bore MRI-guided biopsy upgraded 60% (18 of 30) and downgraded 3.3% (one of 30) of detected lesions. The false-negative rate was 35% (14.2% [two of 14] of patients had CSCs; GS ≥ 7), was higher in prostate volumes of greater than 40 mL, and was lower in the anterior gland location (P = .04 and .01, respectively).

Conclusion

Performing confirmatory in-bore MRI-guided biopsy following positive transrectal US-guided biopsy resulted in a high disease-upgrade incidence with subsequently improved disease-risk stratification, particularly when considering patients for active surveillance or focal therapy. Supplemental material is available for this article. © RSNA, 2020See also the commentary by Weiss and Solomon in this issue.

MRI/TRUS fusion vs. systematic biopsy: intra-patient comparison of diagnostic accuracy for prostate cancer using PI-RADS v2

OBJECTIVE

To evaluate the efficacy of multiparametric magnetic resonance/transrectal ultrasound fusion (MRI/TRUS fusion) biopsy versus systematic biopsy and its association with PI-RADS v2 categories in patients with suspected prostate cancer.

MATERIALS AND METHODS

122 patients undergoing both MRI/TRUS fusion and systematic biopsy, with suspicion of prostate cancer, with suspicious findings on MRI based on PI-RADS v2, were included between April 2016 and March 2017. Comparison of tumor detection rates using each technique and combined techniques was performed for all lesions as well as those that are traditionally difficult to access (i.e., anterior lesions).

RESULTS

Prostate cancer was detected in 83/122 patients (68%) with 74.6% clinically significant lesions (Gleason 3 + 4 or greater). There was a statistically significant difference in presence of clinically significant prostate cancer in PI-RADS v2 categories of 3, 4, and 5 (20%, 52% and 77%, respectively, p < 0.001). Fusion biopsy was positive in a significantly higher percentage of patients versus systematic biopsy (56% versus 48%, respectively, p < 0.05). The fusion biopsy alone was positive in 20%. Of 34 patients with anterior lesions on MRI, 44% were detected only by fusion biopsy, with a joint yield of 71%. In patients with previous negative systematic biopsies, 48.7% lesions were found by fusion biopsy with 20.5% being exclusively positive by this method. The percentage of positive cores for fusion biopsies was significantly higher than for systematic biopsies (26% vs. 12.3%, p < 0.001).

CONCLUSION

The incorporation of MRI/TRUS fusion biopsy significantly improves the detection rate of prostate cancer versus systematic biopsy, particularly for anterior lesions.

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

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

Active Surveillance of Prostate Cancer Using Multiparametric Magnetic Resonance Imaging: A Review of the Current Role and Future Perspectives

Clinically, active surveillance involves continuous monitoring of patients who may be at risk for disease. Patients with low-grade and early-stage prostate cancer may benefit from active surveillance, rather than undergoing surgical and medical treatments that are associated with side effects. In these cases, the role of active surveillance is to ensure that there is no progression of the disease. However, active surveillance may be associated with a risk of under-diagnosis. Previously, the assignment of risk categories and patient monitoring were based on digital rectal examination, transrectal prostate biopsy, and monitoring of serum levels of prostate-specific antigen (PSA). Multiparametric magnetic resonance imaging (MRI) of the prostate gland has an estimated negative predictive value of 95% for the detection of prostate cancer, which makes this an effective imaging method for targeting biopsies and for monitoring patients over time. Also, multiparametric MRI-guided biopsy at the initial stage of the risk stratification for patients who are newly diagnosed with prostate cancer may reduce the number of underdiagnosed patients, improve long-term patient prognosis, and reduce the number of patients who are overtreated, which may reduce healthcare costs and reduce treatment morbidity. For these reasons, multiparametric MRI has become an accepted monitoring tool in patients who are enrolled in active surveillance programs. This review aims to present the current status of the use of multiparametric MRI in active surveillance of prostate cancer and to discuss future perspectives, supported by recent literature.

Survey on the practice of active surveillance for prostate cancer from the Middle East

Background

Prostate cancer is the most common cancer among Lebanese men. Management of prostate cancer includes medical, radiological, and surgical intervention. In addition, active surveillance (AS) is proven as a valid option in patients with low-risk prostate cancer. Currently, data from the Middle East about AS are scarce. The aim of this study is to assess the rate of implementation of AS by physicians, determine the selection and follow-up criteria used by physicians, and identify potential barriers to its widespread adoption.

Methods

After receiving ethical approval, a LimeSurvey electronic questionnaire was mailed to 206 eligible urologists, oncologists, and radiation oncologists registered in the order of physicians in Lebanon. The questionnaire included dichotomous, multiple choice questions, and multiple answer questions. The 23 questions tackled sociodemographic information, physician's attitude toward AS, and their current practices. Predictors of AS use were identified using the chi-squared and Fisher's exact test. Then, multivariate logistic regression model for the predictors of AS practice was conducted.

Results

The response rate was 25%, and the analysis was run on 52 respondents. Although most of the respondents agreed that AS is a valid modality for low-risk prostate cancer, only 34 (65.4%) of them had patients on active surveillance. The rate of patients on AS was also very low. Urologists, physicians with >15 years of experience, and those who practiced in a university hospital were all predictors of AS usage (p = 0.005; p = 0.002; p = 0.025, respectively). However, physicians with fear of patient noncompliance had the odds of resorting to this modality [odds ratio (OR) = 0.07 (0.01 – 0.76)].

Conclusion

The main obstacles to implementing AS were fear of patient noncompliance and lack of national awareness as well as acceptance among the Lebanese uro-oncological body. Efforts to decentralize knowledge and expertize to new health-care practitioners and community hospitals would encourage its implementation.

Evolution of prostate cancer diagnosis: retrospective analysis of magnetic resonance imaging/ultrasound fusion guided biopsies protocol in routine practice and patients management

Background

Magnetic resonance imaging (MRI) is today strongly recommended in prostate cancer (PCa) diagnosis. Therefore, MRI/ultrasound (MRI/US) fusion-guided biopsy is becoming the new standard patients management.

Methods

We report our experience during the last 4 years using this technique, with a protocol of 6 random cores (instead of the most used 12 cores protocol) associated to the target cores (2 to 3 per lesion). Our study involved 236 patients including real life routine practice: biopsy naïve patients (n=107), patients with previous negative standard prostate biopsies (n=67) and patients in PCa active surveillance (n=62). Finally, 76 patients have a robotic radical prostatectomy.

Results

Mean age of the population was 66 years. Median PSA was 8.5 ng/mL. Overall and significant cancer detection were respectively 66.6% and 38.5%, with a large difference considering biopsy history: 63.5% in biopsy naïve patient, 53.7% in patient with previous negative biopsies and 82.3% in patients under active surveillance. Targeted biopsies missed 28 cancers among 8 were significant and standard biopsies missed 33 cancers among 14 were significant. Moreover, concordance between biopsy samples and radical prostatectomy specimens was evaluated at 80%.

Conclusions

Comparing to literature data, similar results were observed in our retrospective study, even with reduced random cores, suggesting a real change in patients management in particular in active surveillance group with a reclassification rate of 56.4% using the Epstein criteria.

Long-Term Outcomes of Active Surveillance for Prostate Cancer: The Memorial Sloan Kettering Cancer Center Experience

PURPOSE

We report oncologic outcomes for men with Grade Group 1 prostate cancer managed with active surveillance at a tertiary cancer center.

MATERIALS AND METHODS

A total of 2,907 patients were managed with active surveillance between 2000 and 2017, of whom 2,664 had Grade Group 1 disease. Patients were recommended confirmatory biopsy to verify eligibility and were followed semiannually with prostate specific antigen, digital rectal examination and review of symptoms. Magnetic resonance imaging was increasingly used in recent years. Biopsy was repeated every 2 to 3 years or after a sustained prostate specific antigen increase or changes in magnetic resonance imaging/digital rectal examination. The Kaplan-Meier method was used to estimate probabilities of treatment, progression and development of metastasis.

RESULTS

Median patient age at diagnosis was 62 years. For men with Grade Group 1 prostate cancer the treatment-free probability at 5, 10 and 15 years was 76% (95% CI 74-78), 64% (95% CI 61-68) and 58% (95% CI 51-64), respectively. At 5, 10 and 15 years there were 1,146, 220 and 25 men at risk for metastasis, respectively. Median followup for those without metastasis was 4.3 years (95% CI 2.3-6.9). Distant metastasis developed in 5 men. Upon case note review only 2 of these men were deemed to have disease that could have been cured on immediate treatment. The risk of distant metastasis was 0.6% (95% CI 0.2-2.0) at 10 years.

CONCLUSIONS

Active surveillance is a safe strategy over longer followup for appropriately selected patients with Grade Group 1 disease following a well-defined monitoring plan.

Can high resolution micro-ultrasound replace MRI in the diagnosis of prostate cancer?

High resolution micro-ultrasound (micro-u/s) is a novel technology that permits visualization of lesions suspicious for prostate cancer. The resolution of 70 μ, that of a prostatic duct, means that alterations in ductal anatomy and cellular density are readily apparent. Initial experience in multiple centers comparing it to mpMRI suggests that the sensitivity for clinically significant prostate cancer is comparable or superior. Specificity is comparable or mildly reduced. Micro-u/s is an inexpensive, accessible and convenient alternative to mpMRI for imaging and diagnosing prostate cancer.

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

Importance

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

Objective

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

Design, Settings, and Participants

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

Exposures

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

MRI to guide biopsies or avoid biopsies?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

The use of prostate MR for targeting prostate biopsies

Management of prostate cancer relies heavily on accurate risk stratification obtained through biopsies, which are conventionally performed under transrectal ultrasound (TRUS) guidance. Yet, multiparametric MRI has grown to become an integral part of the care of males with known or suspected prostate cancer. This article will discuss in detail the different MRI-targeted biopsy techniques, their advantages and disadvantages, and the impact they have on patient management.

The clinical utility of prostate cancer heterogeneity using texture analysis of multiparametric MRI

PURPOSE

To determine if multiparametric MRI (mpMRI) derived filtration-histogram based texture analysis (TA) can differentiate between different Gleason scores (GS) and the D'Amico risk in prostate cancer.

METHODS

We retrospectively studied patients whose pre-operative 1.5T mpMRI had shown a visible tumour and who subsequently underwent radical prostatectomy (RP). Guided by tumour location from the histopathology report, we drew a region of interest around the dominant visible lesion on a single axial slice on the T2, Apparent Diffusion Coefficient (ADC) map and early arterial phase post-contrast T1 image. We then performed TA with a filtration-histogram software (TexRAD -Feedback Medical Ltd, Cambridge, UK). We correlated GS and D'Amico risk with texture using the Spearman's rank correlation test.

RESULTS

We had 26 RP patients with an MR-visible tumour. Mean of positive pixels (MPP) on ADC showed a significant negative correlation with GS at coarse texture scales. MPP showed a significant negative correlation with GS without filtration and with medium filtration. MRI contrast texture without filtration showed a significant, negative correlation with D'Amico score. MR T2 texture showed a significant, negative correlation with the D'Amico risk, particularly at textures without filtration, medium texture scales and coarse texture scales.

CONCLUSION

ADC map mpMRI TA correlated negatively with GS, and T2 and post-contrast images with the D'Amico risk score. These associations may allow for better assessment of disease prognosis and a non-invasive method of follow-up for patients on surveillance. Further, identifying clinically significant prostate cancer is essential to reduce harm from over-diagnosis and over-treatment.

A decision analysis comparing 3 active surveillance protocols for the treatment of patients with low-risk prostate cancer

BACKGROUND

Active surveillance (AS) is a viable management option for approximately 50% of men who are newly diagnosed with prostate cancer. To the authors' knowledge, no direct comparisons between the different variants of AS protocols have been conducted to date. The authors developed a microsimulation decision model to evaluate which of 3 alternative AS protocols is optimal for men with low-risk prostate cancer, and compared each of these with immediate treatment.

METHODS

Men who were diagnosed with low-risk prostate cancer at age 65 years were modeled as having been treated with either immediate therapy or via each of 3 AS protocols. Modeled AS protocols represent those in the literature; a modified AS protocol was included in a sensitivity analysis. Immediate therapy included radical prostatectomy, external-beam radiotherapy, or brachytherapy. Outcome measures were quality-adjusted life-years (QALYs) and costs. Cost-effectiveness analysis and deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Immediate therapy produced fewer QALYs than all variants of AS. Of the AS protocols evaluated, biennial biopsy was found to be the only efficient option, with an incremental cost-effectiveness ratio of $3490 per QALY compared with immediate therapy. It delayed the need for curative therapy by a mean of 56 months, and was found to be preferred in >86.9% of cases in probabilistic sensitivity analysis. A modified version of low-intensity AS dominated all other options.

CONCLUSIONS

For a 65-year-old man with low-risk prostate cancer, AS with biennial biopsy appears to be highly cost-effective compared with common alternatives. An AS protocol using triennial biopsy was found to dominate all other strategies and should be considered for men who are comfortable with a longer period between biopsies. The optimal strategy depends on a patient's tolerance for periodic biopsies and comfort with delaying radical treatment. Physicians should incorporate these patient preferences into decision making.

Can SUVmax values of Ga-68-PSMA PET/CT scan predict the clinically significant prostate cancer?

PURPOSE

The intensity of prostate-specific membrane antigen (PSMA) expression increases as the tumor grade increases and the uptake of Ga-68-PSMA is higher in high-grade tumors. The aim of the present study was to evaluate the correlation of preoperative tracer uptake of primary tumor to Gleason Score in patients who underwent prostatectomy.

PATIENTS AND METHODS

We retrospectively evaluated 141 patients who had Ga-68-PSMA positron emission tomography/computed tomography (PET/CT) imaging and who underwent prostatectomy. All patients had a diagnosis of prostate cancer on the basis of 10-24 cores transrectal ultrasound-guided biopsy (TRUS-Bx). Histological assessment was performed according to the New Contemporary Prostate Cancer Grading System. All patients had a prostate-specific antigen (PSA) level measurement within maximum of 28 days before Ga-68-PSMA PET/CT. Region of interests were drawn manually around the prostate gland, avoiding the bladder activity, to calculate the maximum standardized uptake values (SUVmax) values.

RESULTS

The median PSA values for all patients were 10.0 ng/ml. PSA values for low-risk patients were significantly lower than those of high-risk patients (P<0.001). There were 41.1% upgrades and 7.8% downgrades following prostatectomy in terms of Grade Groups. According to the final pathology reports, 21% (n=16) of patients moved from a low-risk level (grade groups 1+2) to a high-risk level (grade groups 3+4+5). The median SUVmax value was 8.8, ranging from 2.1 to 62.4. There was a strong correlation between SUVmax values and grade groups (Pearson ρ=0.66) (P<0.001). The mean SUVmax values of high-risk patients were significantly higher than those of low-risk patients (18.9±12.1 vs. 7.16±6.2, respectively) (P<0.001). Receiver operation characteristic curve analysis of SUVmax at the cut-off value of 9.1 showed a high sensitivity (78%) and specificity (81%) for detection of high risk disease.

CONCLUSION

SUVmax values correlate significantly with the grade groups of the primary tumor. The intraprostatic accumulation sites may predict clinically significant cancer and potentially serve as a target for biopsy sampling in conjunction with mpMRI in selected patients.

The natural history of prostate cancer on MRI: lessons from an active surveillance cohort

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) is being used increasingly in the setting of active surveillance (AS) for prostate cancer. We investigated changes in the mpMRI appearance of lesions on AS, to show the variability of volume measurements in visible lesions and assess change in lesion size according to grade.

METHODS

We retrospectively retrieved 86 men on AS (NICE guidelines) with more than one mpMRI (the first before 2013). Two radiologists, in consensus, were blinded to patient demographics and date of scan. The scans were randomly reported to reduce any bias. For visible lesions, we measured volume by planimetry on the sequence best showing the most conspicuous (index) tumour and attributed a 5-point Likert score.

RESULTS

43/86 men did not have a visible lesion on the initial mpMRI (≤2/5). Of these, 5/43 had developed a lesion scoring ≥3/5 at a median of 3.6 years of follow up. 40/86 had a lesion scoring ≥3/5 on two or more scans. There was a significant increase in volume over 3.6 years by a median of 10% (p < 0.01)-by a median of 6% for Gleason 3+3 and 18% for 3+4 (p = 0.058). Thirty-five men had a visible lesion on two scans separated by <2 years; of these, 21/35 showed a 78% median increase in tumour size between the two scans and 11/35 showed an apparent 25% median decrease in lesion size.

CONCLUSIONS

A total of 17% of men with no visible lesion developed a visible lesion at a median follow up of 3.6 years. It is possible to show significant growth in patients with a visible lesion, but variability in volume measurements between scans means that it is difficult to reliably detect increases of this order. This variability may inform the design of mpMRI protocols in AS and the time between follow up scans.

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.

Comparison of conventional transrectal ultrasound, magnetic resonance imaging, and micro-ultrasound for visualizing prostate cancer in an active surveillance population: A feasibility study

INTRODUCTION

Active surveillance monitoring of prostate cancer is unique in that most patients have low-grade disease that is not well-visualized by any common imaging technique. High-resolution (29 MHz) micro-ultrasound is a new, real-time modality that has been demonstrated to be sensitive to significant prostate cancer and effective for biopsy targeting. This study compares micro-ultrasound imaging with magnetic resonance imaging (MRI) and conventional ultrasound for visualizing prostate cancer in active surveillance.

METHODS

Nine patients on active surveillance were imaged with multiparametric (mp) MRI prior to biopsy. During the biopsy procedure, imaging and target identification was first performed using conventional ultrasound, then using micro-ultrasound. The mpMRI report was then unblinded and used to determine cognitive fusion targets. Using micro-ultrasound, biopsy samples were taken from targets in each modality, plus 12 systematic samples.

RESULTS

mpMRI and micro-ultrasound both demonstrated superior sensitivity to Gleason sum 7 or higher cancer compared to conventional ultrasound (p=0.02 McNemar's test). Micro-ultrasound detected 89% of clinically significant cancer, compared to 56% for mpMRI.

CONCLUSIONS

Micro-ultrasound may provide similar sensitivity to clinically significant prostate cancer as mpMRI and visualize all significant mpMRI targets. Unlike mpMRI, micro-ultrasound is performed in the office, in real-time during the biopsy procedure, and so is expected to maintain the cost-effectiveness of conventional ultrasound. Larger studies are needed before these results may be applied in a clinical setting.

Active surveillance review: contemporary selection criteria, follow-up, compliance and outcomes

The primary goal of active surveillance (AS) is to prevent overtreatment by selecting patients with low-risk prostate cancer (PCa) and closely monitoring them so that definitive treatment can be offered when needed. With the increasing popularity of AS as a management strategy for men with localized PCa, it is important to understand all the contemporary guidelines and criteria that exist for AS and the differences among them. No single optimal management strategy for clinically localized, early-stage disease has been universally accepted. The implementation of AS varies widely between institutions, from inclusion criteria to follow-up protocols, with the most notable differences seen in maximum accepted Gleason score, T-stage and prostate-specific antigen (PSA) parameters. The objectives of this review were to systematically summarize the current literature on AS strategy, present an overview of the various published guidelines and criteria that are used for AS at several major institutions as well as discuss goals and trade-offs of the various criteria. A comprehensive search of the PubMed and Embase databases from 1990 to 2017 was performed to identify studies pertaining to AS criteria and trends. Trends in AS uptake and use in Canada, USA and Europe were reviewed to demonstrate the current trends and outcomes of AS to offer greater insight into the differences, nature and efficacy of various AS protocols. AS is a compelling antidote to the current PCa overtreatment phenomena; however, when considering patients for AS it is important to understand the differences between protocols, and review published results to appreciate the impact on follow-up.

Is prostate specific antigen (PSA) density necessary in selecting prostate cancer patients for active surveillance and what should be the cutoff in the Asian population?

Background

To investigate the role of Prostate Specific Antigen density (PSAD) in selecting prostate cancer patients for active surveillance (AS) and to determine a cutoff PSAD in identifying adverse pathological outcomes.

Methods

Data from 287 patients who underwent radical prostatectomy for prostate cancer were retrospectively reviewed. Six different AS protocols, the University of Toronto; Royal Marsden; John Hopkins; University of California San Francisco (UCSF); Memorial Sloan Kettering Cancer Center (MSKCC) and Prostate Cancer Research International: Active Surveillance (PRIAS), were applied to the cohort. Pre-operative demographics and pathological outcomes were analysed. Statistical analyses on the predictive factors of adverse pathological outcomes and significance of PSAD were performed. A cutoff PSAD with best balance between sensitivity and specificity in identifying adverse pathological outcome was determined.

Results

PSAD predicted adverse pathological outcomes better than Prostate Specific Antigen (PSA) level alone. The PSAD was significantly lower (0.12-0.13 ng/dl/ml) in protocols including PSAD (the John Hopkins and PRIAS) compared with the other four protocols not including PSAD as a selection criteria (0.21-0.25 ng/dl/dl, P = 0.00). PSAD predicted adverse pathological outcomes in all protocols not incorporating PSAD as an inclusion criteria (P = 0.00-0.02). By the receiver operator characteristics curve analysis, it was found that a PSAD level of 0.19 ng/ml/ml had the best balance between sensitivity and specificity in predicting pathological adverse disease (Area under curve = 0.63, P = 0.004).

Conclusion

PSAD is necessary in selecting prostate cancer patients for active surveillance. It predicts adverse pathological outcomes in patients eligible for active surveillance better than PSA level alone. A PSAD cutoff at 0.19 ng/ml/ml has the best balance between sensitivity and specificity in predicting pathological adverse disease. We recommend using AS protocol incorporating PSAD as a selection criteria (in particular the PRIAS protocol with a cutoff PSAD at 0.2 ng/ml/ml) when recruiting prostate cancer patients for AS.

Predictors for the detection of prostate cancer and clinically significant prostate cancer using TRUS-guided biopsy in patients with negative initial biopsy results

PURPOSE

We aimed to determine the predictors for the detection of prostate cancer and clinically significant prostate cancer in the setting of repeat prostate biopsy using trans-rectal ultrasonography-guided biopsy.

METHODS

A total of 636 patients who underwent repeat prostate biopsy were included. The patients were divided into two groups according to the repeat biopsy results (with vs. without prostate cancer). A multivariable analysis was performed to assess the predictors for the detection of prostate cancer and clinically significant prostate cancer.

RESULTS

Prostate cancer was detected in 98 patients (15.4%). Although there was no difference in the prostate-specific antigen velocity, the prostate-specific antigen density was higher in the patients with prostate cancer at the initial (0.14 vs. 0.17 ng/mL/cc, p = 0.049) and repeat biopsies (0.17 vs. 0.26 ng/mL/cc, p < 0.001). The proportions of the patients who met the active surveillance criteria were as follows: 22.4% (Johns Hopkins), 30.6% (University of Toronto), 32.7% (University of California at San Francisco), 30.6% (Prostate Cancer Research International Active Surveillance), 27.6% (Memorial Sloan Kettering Cancer Center), and 13.3% (University of Miami). In the multivariable analysis, age, hypoechoic lesion on trans-rectal ultrasonography, and prostate-specific antigen density at the repeat biopsy were the significant predictors for prostate cancer and clinically significant prostate cancer.

CONCLUSIONS

Trans-rectal ultrasonography before repeat prostate biopsy and the prostate-specific antigen density are useful for selecting patients with a high probability for prostate cancer if repeat trans-rectal ultrasonography-guided biopsy is considered. In addition, these are also helpful for detecting clinically significant prostate cancer.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Prognostic influence of 5 alpha reductase inhibitors in patients with localized prostate cancer under active surveillance

Objective

The incidence of prostate adenocarcinoma (PCa) is increased with the use of prostate-specific antigen (PSA). In the current study, we aimed to investigate the impact of 5- alpha- reductase inhibitors (5-ARI) on pathological progression in patients followed by active surveillance (AS).

Material and methods

Records of 69 patients with localized prostate cancer under AS (PSA ≤15 ng/mL, PSAD ≤0.20, ≤cT2c, Gleason sum ≤3+3, the number of cancer positive cores ≤3) were evaluated retrospectively. Patients were followed-up with quarterly PSA testing and semiannual digital rectal examination during the first 2 years, and semiannual PSA testing thereafter. Repeat biopsies were done annually and whenever indicated by clinical findings. Pathological progression was defined as increasing Gleason grade, number of cancer-positive cores, and/or increasing percentage of cancer in any core.

Results

Patients using (29/69: 42%) and not using (40/69: 58%) 5-ARI were followed for a median of 39 (IQR: 23-45) and 23.5 (IQR: 17-37.5) months, respectively. Pathological progression was observed in 32% (22/69) of the patients at a median of 25 (IQR: 18-39) months. Pathological progression was observed in 34.5% (10/29) and 30% (12/40) of the patients using and not using 5-ARI, respectively (Log-rank p=0.4151). Definitive treatment was done in 31% (9/29) and 47.5% (19/40) of the patients using and not using 5-ARI, respectively. Patients who did not use 5-ARI received definitive treatment earlier than 5-ARI users (Log-rank p=0.0342). On multivariate analysis, more than 2 cancer-positive cores (HR: 11.62) and age (HR: 0.94) were independently associated with pathological progression (p<0.05), rather than 5-ARI use (p=0.148).

Conclusion

More than 2 cancer- positive cores at the initial biopsy was the strongest covariate associated with pathological progression; these patients should not be offered AS. There was no impact of 5-ARI use on pathological progression in AS.

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.

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.

Targeted Ablative Therapies for Prostate Cancer

Men diagnosed with low- to intermediate-risk, clinically localized prostate cancer (PCa) often face a daunting and difficult decision with respect to treatment: active surveillance (AS) or radical therapy. This decision is further confounded by the fact that many of these men diagnosed, by an elevated PSA, will have indolent disease and never require intervention. Radical treatments, including radical prostatectomy and whole-gland radiation, offer greater certainty for cancer control, but at the risk of significant urinary and/or sexual morbidity. Conversely, AS preserves genitourinary function and quality of life in exchange for burdensome surveillance and the psychological impact of living with cancer.

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.

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

A novel biopsy-related parameter derived from location and relationship of positive cores on standard 12-core trans-rectal ultrasound-guided prostate biopsy: a useful parameter for predicting tumor volume compared to number of positive cores

PURPOSE

To develop a novel biopsy-related parameter, named overlapping line, defined as the line between the adjacent positive cores on 12-core trans-rectal ultrasound-guided prostate biopsy, and evaluated the value of overlapping line for predicting tumor volume in the final pathologic examination.

METHODS

Among patients with prostate cancer who underwent radical prostatectomy at Boramae Medical Center, 470 patients who underwent standard 12-core trans-rectal ultrasound-guided prostate biopsy were selected for the analysis. The number of overlapping line was determined in each patient, and its effects on tumor volume were evaluated after adjusting for other variables.

RESULTS

Median prostate specific antigen level was 9.1 ng/mL, and the maximum % cancer in positive cores was 42.8%. Median numbers of positive cores and overlapping lines were three and two, respectively. The pathologic stage was T2 or less, T3a, and T3b or greater in 297 (63.5%), 104 (22.2%), and 67 patients (14.3%), respectively. Median tumor volume in prostatectomy specimen was 3.4 mL. In multivariable analysis, the number of overlapping lines (B 0.750, p < 0.001) was a significant predictor for tumor volume, in addition to prostate specific antigen level and maximum % cancer in positive cores. In addition, the model with overlapping line showed superior accuracy compared to the model with positive core based adjusted r ² (0.467 vs. 0.456).

CONCLUSIONS

The number of overlapping lines, a novel prostate biopsy-related variable, is thought to be a more reliable predictor for tumor volume compared to the number of positive cores and could be easily applied to routine daily practice.