Multiparametric Magnetic Resonance Imaging Should Be Preferred Over Digital Rectal Examination for Prostate Cancer Local Staging and Disease Risk Classification

Preoperative multiparametric magnetic resonance imaging based risk stratification system for predicting biochemical recurrence after radical prostatectomy

BACKGROUND

Multiparametric magnetic resonance imaging (mpMRI) is used as a current marker in preoperative staging and surgical decision-making, but current evidence on predicting post-surgical oncological outcomes based on preoperative mpMRI findings is limited. In this study We aimed to develop a risk classification based on mpMRI and mpMRI-derived biopsy findings to predict early biochemical recurrence (BCR) after radical prostatectomy.

METHODS

Between January 2017 and January 2023, the data of 289 patients who underwent mpMRI, transrectal ultrasound-guided cognitive and fusion targeted biopsies, and subsequent radical prostatectomy (RP) with or without pelvic lymph node dissection in a single center were retrospectively re-evaluated. BCR was defined as a prostate specific-antigen (PSA) ≥ 0.2 ng/mL at least twice after RP. Multivariate logistic regression models tested the predictors of BCR. The regression tree analysis stratified patients into risk groups based on preoperative mpMRI characteristics. Receiver operating characteristic (ROC)-derived area under the curve (AUC) estimates were used to test the accuracy of the regression tree-derived risk stratification tool.

RESULTS

BCR was detected in 47 patients (16.2 %) at a median follow-up of 24 months. In mpMRI based multivariate analyses, the maximum diameter of the index lesion (HR 1.081, 95%Cl 1.015-1.151, p = 0.015) the presence of PI-RADS 5 lesions (HR 2.604, 95%Cl 1.043-6.493, p = 0.04), ≥iT3a stage (HR 2.403, 95%Cl 1.013-5.714, p = 0.046) and ISUP grade ≥4 on biopsy (HR 2.440, 95%Cl 1.123-5.301, p = 0.024) were independent predictors of BCR. In regression tree analysis, patients were stratified into three risk groups: maximum diameter of index lesion, biopsy ISUP grade, and clinical stage on mpMRI. The regression tree-derived risk stratification model had moderate-good accuracy in predicting early BCR (AUC 77 %) CONCLUSION: Straightforward mpMRI and mpMRI-derived biopsy-based risk stratification for BCR prediction provide an additional clinical predictive model to the currently available pathological risk tools.

The Added Value of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography to Magnetic Resonance Imaging for Local Staging of Prostate Cancer in Patients Undergoing Radical Prostatectomy

BACKGROUND AND OBJECTIVE

The role of prostate-specific membrane antigen (PSMA)-based positron emission tomography (PET)/computed tomography (CT) in addition to magnetic resonance imaging (MRI) for local staging of prostate cancer (PC) has been poorly addressed so far. Our aim was to assess the diagnostic accuracy of PSMA PET/CT and MRI, alone and combined, for detection of extraprostatic extension (EPE) and seminal vesicle invasion (SVI) in PC.

METHODS

We conducted a multicenter retrospective study evaluating patients undergoing PSMA PET/CT and MRI before radical prostatectomy. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC) for detection of EPE and SVI were calculated for MRI and PSMA PET/CT alone and combined.

KEY FINDINGS AND LIMITATIONS

We included 550 patients, of whom 2%, had low-risk, 43% had intermediate-risk, and 55% had high-risk PC. Overall, 52% of patients had EPE and 21% had SVI at histopathology. Patient-based comparison of MRI versus PSMA PET/CT for detection of EPE revealed sensitivity of 60% versus 41% (p < 0.001), specificity of 77% versus 83% (p = 0.075), PPV of 75% versus 73% (p = 0.6), NPV of 64% versus 56% (p < 0.001), and AUC of 69% versus 62% (p = 0.01). Combining the modalities increased the sensitivity (73%; p < 0.001) and NPV (69%; p < 0.001) and decreased the specificity (67%; p < 0.001) and PPV (71%; p = 0.01) over MRI alone. Patient-based comparison of MRI versus PSMA PET/CT for detection of SVI revealed sensitivity of 36% versus 44% (p = 0.2), specificity of 96% versus 96% (p > 0.99), PPV of 71% versus 75% (p = 0.6), NPV of 85% versus 87% (p = 0.2), and AUC of 66% versus 70% (p = 0.2). Combining the modalities increased the sensitivity (60%; p < 0.001), NPV (90%; p < 0.001), and AUC (76%; p < 0.001) and decreased the specificity (92%; p < 0.001) over MRI alone. Limitations include the retrospective nature of the study, selection of higher-risk cases for PSMA PET/CT, and lack of central review.

CONCLUSIONS AND CLINICAL IMPLICATIONS

PSMA PET/CT has lower sensitivity for EPE detection in comparison to MRI. However, addition of PSMA PET information to MRI improved the sensitivity for EPE and SVI detection. Thus, the two modalities should be combined to guide treatment selection.

PATIENT SUMMARY

Combining MRI (magnetic resonance imaging) scans with another type of imaging called PSMA PET/CT (prostate-specific membrane antigen positron emission tomography/computed tomography) for patients with prostate cancer leads to better identification of cancer growth outside the prostate in comparison to MRI alone. This could potentially improve the choice of prostate cancer treatment.

Changing times: trends in risk classification, tumor upstaging, and positive surgical margins after radical prostatectomy - results from a contemporary National Cancer Database study

PURPOSE

Recent advancements in screening, prostate MRI, robotic surgery, and active surveillance have influenced the profile of patients undergoing radical prostatectomy (RP). We sought to examine their impact on trends in clinicodemographic, risk classification, and adverse pathology in men undergoing surgery.

METHODS

We queried the National Cancer Database for clinicodemographic, risk group, and pathology data in men undergoing upfront RP between 2006 and 2020. Patients were categorized by NCCN risk groups, and trends were assessed among 2006-2010, 2011-2015, and 2016-2020 periods. Endpoints included rates of pT3, positive surgical margins (PSM), pathologic upstaging, and Gleason grade group (GG) upgrading.

RESULTS

610,762 patients were included. There were significant increases in African Americans (9.8-14.1%), comorbidities (2.1-5.2% with Charlson scores > 1), and robot-assisted RP (78-84%). Over the three time periods, high-risk cases increased from 15 to 20 to 27%, and intermediate-risk from 54 to 51 to 60%. Overall rates of pT3 rose from 20 to 38%, and PSM from 20 to 27% (p < 0.001). Pathologic upstaging increased in low (6-15%), intermediate (20-33%), and high-risk groups (42-58%) -p < 0.001. Gleason upgrading rose in low-risk (45-59%, p < 0.001), with slight reductions in the intermediate and high-risk groups.

CONCLUSIONS

Recent trends in RP indicate a shift towards more advanced disease, evidenced by increasing rates of pT3, PSM, and pathologic upstaging across all NCCN risk groups. These findings emphasize the need for a careful balance in applying fascia and nerve-sparing techniques to avoid compromising oncological safety.

EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer-2024 Update. Part I: Screening, Diagnosis, and Local Treatment with Curative Intent

BACKGROUND AND OBJECTIVE

The European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Urological Pathology (ISUP)-International Society of Geriatric Oncology (SIOG) guidelines provide recommendations for the management of clinically localised prostate cancer (PCa). This paper aims to present a summary of the 2024 version of the EAU-EANM-ESTRO-ESUR-ISUP-SIOG guidelines on the screening, diagnosis, and treatment of clinically localised PCa.

METHODS

The panel performed a literature review of all new data published in English, covering the time frame between May 2020 and 2023. The guidelines were updated, and a strength rating for each recommendation was added based on a systematic review of the evidence.

KEY FINDINGS AND LIMITATIONS

A risk-adapted strategy for identifying men who may develop PCa is advised, generally commencing at 50 yr of age and based on individualised life expectancy. The use of multiparametric magnetic resonance imaging in order to avoid unnecessary biopsies is recommended. When a biopsy is considered, a combination of targeted and regional biopsies should be performed. Prostate-specific membrane antigen positron emission tomography imaging is the most sensitive technique for identifying metastatic spread. Active surveillance is the appropriate management for men with low-risk PCa, as well as for selected favourable intermediate-risk patients with International Society of Urological Pathology grade group 2 lesions. Local therapies are addressed, as well as the management of persistent prostate-specific antigen after surgery. A recommendation to consider hypofractionation in intermediate-risk patients is provided. Patients with cN1 PCa should be offered a local treatment combined with long-term intensified hormonal treatment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The evidence in the field of diagnosis, staging, and treatment of localised PCa is evolving rapidly. These PCa guidelines reflect the multidisciplinary nature of PCa management.

PATIENT SUMMARY

This article is the summary of the guidelines for "curable" prostate cancer. Prostate cancer is "found" through a multistep risk-based screening process. The objective is to find as many men as possible with a curable cancer. Prostate cancer is curable if it resides in the prostate; it is then classified into low-, intermediary-, and high-risk localised and locally advanced prostate cancer. These risk classes are the basis of the treatments. Low-risk prostate cancer is treated with "active surveillance", a treatment with excellent prognosis. For low-intermediary-risk active surveillance should also be discussed as an option. In other cases, active treatments, surgery, or radiation treatment should be discussed along with the potential side effects to allow shared decision-making.

MRI lesion size is more important than the number of positive biopsy cores in predicting adverse features and recurrence after radical prostatectomy: implications for active surveillance criteria in intermediate-risk patients

INTRODUCTION

To determine associations between prostate cancer (PCa) tumor burden measured on biopsy or multiparametric magnetic resonance imaging (mpMRI) and outcomes in intermediate-risk (IR) International Society of Urological Pathology (ISUP) grade 2 men managed with primary radical prostatectomy (RP).

METHODS

This retrospective, multicenter study was conducted in eight referral centers. The cohort included IR PCa patients who had ISUP 2 at biopsy. We defined biopsy tumor burden as low/high based on the absence/presence of more than 25% positive cores. Tumor burden on imaging was defined as low/high based on maximum lesion diameter, <15 mm and ≥15 mm at mpMRI, respectively. The histological endpoint of the study was adverse features at RP, defined as ≥pT3a stage and/or lymph node invasion and/or ISUP ≥3 at final pathology. The clinical endpoint was biochemical recurrence (BCR) after RP.

RESULTS

A total of 698 IR patients was included, of whom 335 (48%) had adverse features. In multivariate logistic regression analysis, there was no statistical association between tumor burden at biopsy and adverse features (p = 0.7). Tumor size ≥15 mm at mpMRI was significantly associated with adverse pathology (OR 1.65, 95%CI 1.14-2.39; p = 0.01). No significant association was observed between tumor burden at biopsy and BCR (p = 0.4). Tumor size ≥15 mm at mpMRI was significantly associated with BCR (HR 1.96, 95% CI 1.01-3.80; p = 0.04).

CONCLUSIONS

Our data support extending the inclusion criteria to ISUP 2 men with >25% positive cores, provided they have a low tumor size at mpMRI (<15 mm). Prospective studies should be performed to validate these findings.

Interpreting Prostate MRI Reports in the Era of Increasing Prostate MRI Utilization: A Urologist's Perspective

Multi-parametric prostate MRI (mpMRI) is crucial for diagnosing, staging, and assessing treatment response in individuals with prostate cancer. Radiologists, through an accurate and standardized interpretation of mpMRI, stratify patients who may benefit from more invasive treatment or exclude patients who may be harmed by overtreatment. The integration of prostate MRI into the diagnostic pathway is anticipated to generate a substantial surge in the demand for high-quality mpMRI, estimated at approximately two million additional prostate MRI scans annually in Europe. In this review we examine the immediate impact on healthcare, particularly focusing on the workload and evolving roles of radiologists and urologists tasked with the interpretation of these reports and consequential decisions regarding prostate biopsies. We investigate important questions that influence how prostate MRI reports are handled. The discussion aims to provide insights into the collaboration needed for effective reporting.

The accuracy and intra- and interobserver variability of PSMA PET/CT for the local staging of primary prostate cancer

PURPOSE

Prostate-specific membrane antigen (PSMA) positron emission tomography/ computed tomography (PET/CT) is recognized as the most accurate imaging modality for detection of metastatic high-risk prostate cancer (PCa). Its role in the local staging of disease is yet unclear. We assessed the intra- and interobserver variability, as well as the diagnostic accuracy of the PSMA PET/CT based molecular imaging local tumour stage (miT-stage) for the local tumour stage assessment in a large, multicentre cohort of patients with intermediate and high-risk primary PCa, with the radical prostatectomy specimen (pT-stage) serving as the reference standard.

METHODS

A total of 600 patients who underwent staging PSMA PET/CT before robot-assisted radical prostatectomy was studied. In 579 PSMA positive primary prostate tumours a comparison was made between miT-stage as assessed by four nuclear physicians and the pT-stage according to ISUP protocol. Sensitivity, specificity and diagnostic accuracy were determined. In a representative subset of 100 patients, the intra-and interobserver variability were assessed using Kappa-estimates.

RESULTS

The sensitivity and specificity of the PSMA PET/CT based miT-stage were 58% and 59% for pT3a-stage, 30% and 97% for ≥ pT3b-stage, and 68% and 61% for overall ≥ pT3-stage, respectively. No statistically significant differences in diagnostic accuracy were found between tracers. We found a substantial intra-observer agreement for PSMA PET/CT assessment of ≥ T3-stage (k 0.70) and ≥ T3b-stage (k 0.75), whereas the interobserver agreement for the assessment of ≥ T3-stage (k 0.47) and ≥ T3b-stage (k 0.41) were moderate.

CONCLUSION

In a large, multicentre study evaluating 600 patients with newly diagnosed intermediate and high-risk PCa, we showed that PSMA PET/CT may have a value in local tumour staging when pathological tumour stage in the radical prostatectomy specimen was used as the reference standard. The intra-observer and interobserver variability of assessment of tumour extent on PSMA PET/CT was moderate to substantial.

A Comparison of Globally Applied Prognostic Risk Groups and the Prevalence of Metastatic Disease on Prostate-specific Membrane Antigen Positron Emission Tomography in Patients with Newly Diagnosed Prostate Cancer

BACKGROUND

Various risk classification systems (RCSs) are used globally to stratify newly diagnosed patients with prostate cancer (PCa) into prognostic groups.

OBJECTIVE

To compare the predictive value of different prognostic subgroups (low-, intermediate-, and high-risk disease) within the RCSs for detecting metastatic disease on prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) for primary staging, and to assess whether further subdivision of subgroups would be beneficial.

DESIGN, SETTING, AND PARTICIPANTS

Patients with newly diagnosed PCa, in whom PSMA-PET/CT was performed between 2017 and 2022, were studied retrospectively. Patients were stratified into risk groups based on four RCSs: European Association of Urology, National Comprehensive Cancer Network (NCCN), Cambridge Prognostic Group (CPG), and Cancer of the Prostate Risk Assessment.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The prevalence of metastatic disease on PSMA-PET/CT was compared among the subgroups within the four RCSs.

RESULTS AND LIMITATIONS

In total, 2630 men with newly diagnosed PCa were studied. Any metastatic disease was observed in 35% (931/2630) of patients. Among patients classified as having intermediate- and high-risk disease, the prevalence of metastases ranged from approximately 12% to 46%. Two RCSs further subdivided these groups. According to the NCCN, metastatic disease was observed in 5.8%, 13%, 22%, and 62% for favorable intermediate-, unfavorable intermediate-, high-, and very-high-risk PCa, respectively. Regarding the CPG, these values were 6.9%, 13%, 21%, and 60% for the corresponding risk groups.

CONCLUSIONS

This study underlines the importance of nuanced risk stratification, recommending the further subdivision of intermediate- and high-risk disease given the notable variation in the prevalence of metastatic disease. PSMA-PET/CT for primary staging should be reserved for patients with unfavorable intermediate- or higher-risk disease.

PATIENT SUMMARY

The use of various risk classification systems in patients with prostate cancer helps identify those at a higher risk of having metastatic disease on prostate-specific membrane antigen positron emission tomography/computed tomography for primary staging.

Magnetic resonance imaging targeted biopsy in biopsy-naïve patients and the risk of overtreatment in prostate cancer: a grading issue

OBJECTIVE

To evaluate the impact of applying the 2014 and 2019 International Society of Urological Pathology (ISUP) recommendations on grade group distribution and concordance with radical prostatectomy (RP).

MATERIALS AND METHODS

Overall, 655 biopsy-naïve patients diagnosed by magnetic resonance imaging (MRI) targeted and systematic biopsies for Prostate Imaging Reporting and Data System score ≥3 lesions were identified from a prospectively maintained database from 2016 and 2022. Clinically significant prostate cancer was detected in 249 patients, of whom 69 underwent RP. Wilcoxon signed rank and McNemar's tests were used to compare the ISUP grade group distribution and concordance with RP after applying the 2014 (i.e., highest grade) and 2019 (i.e., global grade) ISUP recommendations, respectively.

RESULTS

Compared to the 2014 ISUP recommendations, the 2019 ISUP recommendations were associated with a significant decrease in ISUP Grade Group 4 (range of difference from -13% to -5%) and an increase in ISUP Grade Group 2 (range of difference from +6% to +11%) in MRI targeted biopsy only, MRI targeted with perilesional biopsies, and MRI targeted with systematic biopsies (all P < 0.01). In patients who underwent RP, a significant decrease in downgrading was observed with all biopsy strategies (range of difference from -19% to -12%; P ≤ 0.008), along with an increase in concordance with RP specimen (range of difference from +12% to +13%; P ≤ 0.02). The use of the 2019 ISUP recommendation was associated with RP specimen a lower treatment burden.

CONCLUSIONS

The use of the 2019 ISUP recommendations mitigates the grade migration induced by MRI targeted biopsy and improves the concordance with the final RP specimen.

Application of Advanced Imaging to Prostate Cancer Diagnosis and Management: A Narrative Review of Current Practice and Unanswered Questions

Major advances in prostate cancer diagnosis, staging, and management have occurred over the past decade, largely due to our improved understanding of the technical aspects and clinical applications of advanced imaging, specifically magnetic resonance imaging (MRI) and prostate-cancer-specific positron emission tomography (PET). Herein, we review the established utility of these important and exciting technologies, as well as areas of controversy and uncertainty that remain important areas for future study. There is strong evidence supporting the utility of MRI in guiding initial biopsy and assessing local disease. There is debate, however, regarding how to best use the imaging modality in risk stratification, treatment planning, and assessment of biochemical failure. Prostate-cancer-specific PET is a relatively new technology that provides great value to the evaluation of newly diagnosed, treated, and recurrent prostate cancer. However, its ideal use in treatment decision making, staging, recurrence detection, and surveillance necessitates further research. Continued study of both imaging modalities will allow for an improved understanding of their best utilization in improving cancer care.

Quantifying the Impact of Cancer on the Viscoelastic Properties of the Prostate Gland using a Quasi-Linear Viscoelastic Model

Pathological disorders can alter the mechanical properties of biological tissues, and studying such changes can help to better understand the disease progression. The prostate gland is no exception, as previous studies have shown that cancer can affect its mechanical properties. However, most of these studies have focused on the elastic properties of the tissue and have overlooked the impact of cancer on its viscous response. To address this gap, we used a quasi-linear viscoelastic model to investigate the impact of cancer on both the elastic and viscous characteristics of the prostate gland. By comparing the viscoelastic properties of segments influenced by cancer and those unaffected by cancer in 49 fresh prostates, removed within two hours after prostatectomy surgery, we were able to determine the influence of cancer grade and tumor volume on the tissue. Our findings suggest that tumor volume significantly affects both the elastic modulus and viscosity of the prostate (p-value less than 2%). Specifically, we showed that cancer increases Young's modulus and shear relaxation modulus by 20%. These results have implications for using mechanical properties of the prostate as a potential biomarker for cancer. However, developing an in vivo apparatus to measure these properties remains a challenge that needs to be addressed in future research. STATEMENT OF SIGNIFICANCE: This study is the first to explore how cancer impacts the mechanical properties of prostate tissues using a quasi-linear viscoelastic model. We examined 49 fresh prostate samples collected immediately after surgery and correlated their properties with cancer presence identified in pathology reports. Our results demonstrate a 20% change in the viscoelastic properties of the prostate due to cancer. We initially validated our approach using tissue-mimicking phantoms and then applied it to differentiate between cancerous and normal prostate tissues. These findings offer potential for early cancer detection by assessing these properties. However, conducting these tests in vivo remains a challenge for future research.

Clinical stage and grade migration of localized prostate cancer at diagnosis during the past decade

OBJECTIVES

Early 2010s data suggest a reverse stage and grade migration towards more aggressive prostate cancer (PCa) at diagnosis, accelerated by the 2012 US Preventive Services Task Force recommendation against PSA screening. Using the National Cancer Database, we investigated the impact of the 2018 USPSTF recommendation and the COVID-19 outbreak on this shift. We hypothesized that the COVID-19 outbreak would further contribute to a stage and grade migration towards more aggressive disease.

MATERIAL AND METHODS

We identified men with localized PCa diagnosed between 2010 and 2020. We analyzed the shift in the proportion of PCa stratified according to D'Amico risk classification. We used multivariable logistic regression models to assess the association between year of diagnosis and dichotomous variables related to clinical stage and grade of PCa. Predicted probabilities with 95% CI were computed through marginal effect analyses.

RESULTS

We identified 910,898 men with localized PCa. The proportion of low-risk PCa almost halved from 34.9% in 2010 to 17.7% in 2020 (P < 0.001). Compared to 2010, we found in each year increased odds of: PSA≥10 ng/dL starting from 2012 (aOR2012 1.05; 95% CI, 1.02-1.08); cT3-T4 starting from 2015 (aOR2015 1.10; 95% CI, 1.03-1.17); ISUP GG 3-5 starting from 2011 (aOR2011 1.06; 95% CI, 1.03-1.08); and consequently, D'Amico intermediate/high-risk class starting from 2011 (aOR2011 1.03; 95% CI, 1.01-1.05). Fluctuations in the probabilities of PSA≥10 ng/dL and cT3-T4 at diagnosis were observed over time (all P < 0.001). The probability of PSA≥10 ng/dL peaked at 29.0% (95% CI, 28.0%-29.0%) in 2018, while the probability of cT3-T4 peaked at 3.7% (95% CI, 3.6%-3.8%) in 2020. All other outcome variables demonstrated a consistent upward shift (all P < 0.001), with the highest probabilities in 2020 for ISUP GG 3-5 (42.3%, 95% CI, 41.9%-42.6%) and D'Amico intermediate/high-risk (81.3%, 95% CI, 81.0%-81.6%).

CONCLUSIONS

Our study confirms an enduring shift towards a higher proportion of aggressive PCa at diagnosis, likely influenced by the COVID-19 pandemic. The impact of the 2018 USPSTF PCa screening recommendation on the proportion of aggressive PCa seems restricted and likely affected by the pandemic outbreak. Future investigations should evaluate the long-term effects of the 2018 USPSTF recommendations in the postpandemic setting.

The Development and External Validation of Artificial Intelligence-Driven MRI-Based Models to Improve Prediction of Lesion-Specific Extraprostatic Extension in Patients with Prostate Cancer

Adequate detection of the histopathological extraprostatic extension (EPE) of prostate cancer (PCa) remains a challenge using conventional radiomics on 3 Tesla multiparametric magnetic resonance imaging (3T mpMRI). This study focuses on the assessment of artificial intelligence (AI)-driven models with innovative MRI radiomics in predicting EPE of prostate cancer (PCa) at a lesion-specific level. With a dataset encompassing 994 lesions from 794 PCa patients who underwent robot-assisted radical prostatectomy (RARP) at two Dutch hospitals, the study establishes and validates three classification models. The models were validated on an internal validation cohort of 162 lesions and an external validation cohort of 189 lesions in terms of discrimination, calibration, net benefit, and comparison to radiology reporting. Notably, the achieved AUCs ranged from 0.86 to 0.91 at the lesion-specific level, demonstrating the superior accuracy of the random forest model over conventional radiological reporting. At the external test cohort, the random forest model was the best-calibrated model and demonstrated a significantly higher accuracy compared to radiological reporting (83% vs. 67%, p = 0.02). In conclusion, an AI-powered model that includes both existing and novel MRI radiomics improves the detection of lesion-specific EPE in prostate cancer.

Prospective analysis of the diagnostic accuracy of digital rectal examination and magnetic resonance imaging for T staging of prostate cancer

Background

Accurate staging of prostate cancer (PCa) is the basis for the risk stratification to select targeted treatment. Therefore, this study aimed to compare the diagnostic accuracy rates of magnetic resonance imaging (MRI) and digital rectal examination (DRE) for preoperative T staging of potentially resectable PCa.

Methods

From March 2021 to March 2022, patients with PCa with T staging by prostate biopsy were included. All examinations used postoperative histopathologic T staging as the reference standard. All patients underwent DRE and MRI before the puncture. Two blinded urologists and radiologists independently evaluated DRE and MRI, respectively. Before the examination, patients were then divided into early- (T1, T2) and late-(T3, T4) stage cancer. Analysis of a paired sample sign test was performed to determine differences between DRE and MRI.

Results

A total of 136 study participants with PCa were evaluated histopathologically, of whom 71% (97/136) and 29% (39/136) were at the early- and late-stage cancer, respectively. MRI had a significantly higher accuracy (91.9% vs. 76.5%, P < 0.001) compared with DRE. Further, MRI showed a higher sensitivity than DRE to diagnose early PCa (92.8% vs. 74.2%; P < 0.001). However, the specificity was not significantly different between them (89.7% vs. 82.1%; P = 0.375). Area under the curve (receiver operating curve) values were calculated as 0.78 ± 0.038 (95% confidence interval [CI], 0.71-0.86), 0.91 ± 0.028 (95% CI, 0.86-0.97), and 0.872 ± 0.028 (95% CI, 0.80-0.92) for DRE-, MRI-, MRI + DRE-based PCa predictions, respectively. The prediction performance of MRI was better than that of DRE (DeLong test, z = 3.632, P = 0.0003) and MRI + DRE (DeLong test, z = 3.715, P = 0.0002).

Conclusion

For resectable PCa, the diagnostic potential of MRI in assessing the T stage was higher than that of DRE. However, DRE is still valuable, especially for patients with locally advanced PCa.

Prostate Adenocarcinoma Grade Group 1: Rationale for Retaining a Cancer Label in the 2022 World Health Organization Classification

We present the rationale for keeping the "cancer" label for grade group 1 (GG1) prostate cancer. Maintaining GG1 as the lowest grade outweighs the potential benefits that a benign designation may bring. Patient and surgeon education on the vital role of active surveillance for GG1 cancers and avoidance of overtreatment should be the focus rather than such a drastic change in nomenclature.

Impact of prebiopsy MRI on prostate cancer staging: Results from the Norwegian Prostate Cancer Registry

Objectives

The aim of this study is to evaluate the 2015 introduction of prebiopsy magnetic resonance imaging of the prostate (MRI-P) as the standard of care for diagnosing prostate cancer (PCa) by the Norwegian public health care authorities. There were three specific objectives of this study: first, to evaluate the consequences of using different TNM manuals for clinical T-staging (cT-staging) in a national setting; second, to determine if the data reveals that MRI-P based cT-staging is superior to digital rectal examination (DRE)-based cT-staging compared with pathological T-stage (pT-stage) post radical prostatectomy; and third, to assess whether treatment allocations have changed over time.

Materials and Methods

All patients registered in the Norwegian Prostate Cancer Registry between 2004 and 2021 were retrieved and 5538 were eligible for inclusion. Concordance between clinical T-stage (cT-stage) and pT-stage was assessed by percentage agreement, Cohen's kappa and Gwet's agreement.

Results

MR visualisation of lesions influences reporting of tumour extension beyond DRE findings. Agreement between cT-stage and pT-stage declined from 2004 to 2009, which coincided with an increase in the percentage being pT3. From 2010, agreement increased, which aligned with changes in cT-staging and the introduction of MRI-P. From 2017, regarding the reporting of cT-DRE and cT-Total (overall cT-stage), agreement diminished for cT-DRE but remained relatively stable (>60%) for cT-Total. Regarding treatment allocation, the study suggests that staging with MRI-P has shifted treatment towards radiotherapy in locally advanced high-risk disease.

Conclusion

Introduction of MRI-P has affected cT-stage reporting. Agreement between cT-stage and pT-stage appears to have improved. This study suggests that use of MRI-P influences treatment decisions in certain patient subgroups.

Optimizing multiparametric magnetic resonance imaging-targeted biopsy and prostate cancer grading accuracy

PURPOSE

To assess the most efficient biopsy method to improve International Society of Urological Pathology (ISUP) grade group accuracy with final pathology of the radical prostatectomy (RP) specimen in the era of magnetic resonance imaging (MRI)-driven pathway.

METHODS

A total of 753 patients diagnosed by transrectal MRI-targeted and systematic biopsies (namely "standard method"), treated by RP, between 2016 and 2021 were evaluated. Biopsy methods included MRI-targeted biopsy, side-specific systematic biopsies relative to index MRI lesion and combination of both. Number of MRI-targeted biopsy cores and positive cores needed per index MRI lesion were assessed. Multivariable analysis was performed to analyze predictive factors of upgrading using MRI targeted and ipsilateral systematic biopsies method.

RESULTS

Overall, ISUP grade group accuracy varied among biopsy methods with upgrading rate of 35%, 49%, 27%, and 24% for MRI targeted, systematic, MRI targeted and ipsilateral systematic biopsies and standard methods, respectively (p < 0.001). A minimum of two positive MRI-targeted biopsies cores per index MRI lesion were required when testing MRI targeted and ipsilateral systematic biopsies method to reach equivalent accuracy compared to standard method. Omitting contralateral systematic biopsies spared an average of 5.9 cores per patient. At multivariable analysis, only the number of positive MRI-targeted biopsy cores per index MRI lesion was predictive of upgrading.

CONCLUSION

MRI targeted and ipsilateral systematic biopsies allowed an accurate definition of ISUP grade group and appears to be an interesting alternative when compared with standard method, reducing total number of biopsy cores needed.

PSMA PET-CT in the Diagnosis and Staging of Prostate Cancer

Prostate cancer is the most common cancer and the second leading cause of cancer death in men. The imaging assessment and treatment of prostate cancer has vastly improved over the past decade. The introduction of PSMA PET-CT has improved the detection of loco-regional and metastatic disease. PSMA PET-CT also has a role in the primary diagnosis and staging, in detecting biochemical recurrence after curative treatment and in metastasis-directed therapy. In this paper we review the role of PSMA PET-CT in prostate cancer.

Magnetic Resonance Imaging–based T-staging to Predict Biochemical Recurrence after Radical Prostatectomy: A Step Towards the iTNM Classification

BACKGROUND

Local staging of prostate cancer (PCa) still relies on digital rectal examination (DRE), which therefore remains the standard for risk stratification in guideline recommendations, clinical trials, and patient counseling. This issue is increasingly controversial as multiparametric magnetic resonance imaging (mpMRI) has become the most influential diagnostic tool for local staging of PCa over the past two decades.

OBJECTIVE

To compare various models of T category based on DRE or mpMRI to predict early biochemical recurrence (BCR) after radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective multicenter cohort study was conducted between 2014 and 2021. A total of 1436 patients were recruited across eight referral centers in France, Italy, Switzerland, and Belgium.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

BCR was defined as two prostate-specific antigen values of ≥0.2 ng/ml during follow-up. Harrell's concordance index (C index) was used to compare the discrimination of four models of T staging based on DRE (model 1: cT1 vs cT2 vs cT3) or mpMRI (model 2: organ-confined disease vs extracapsular extension [iECE] vs seminal vesicle invasion [iSVI]; model 3: Prostate Imaging-Reporting and Data System [PI-RADS] ≤3 vs PI-RADS 4 vs PI-RADS 5; and model 4: iT2a [PI-RADS ≤3] vs iT2b [PI-RADS 4] vs iT2c [PI-RADS 5 excluding ECE or SVI] vs iT3a [ECE] vs iT3b [SVI]) to predict BCR.

RESULTS AND LIMITATIONS

Overall, 74 (5%), 845 (59%), 482 (34%), and 35 (2%) patients had low-, intermediate-, high-, and very high-risk PCa, respectively, according to the Mazzone risk classification. After median follow-up of 16 mo, 113 patients experienced BCR. Although the new five-group mpMRI-based T classification system (model 4) had the highest prognostic discrimination (C index 0.694) for predicting early BCR on multivariable analysis, there was overlap between the 95% confidence intervals of the models. On sensitivity analysis, the new mpMRI-based T staging still had a higher C index than DRE for predicting BCR when excluding cN1 patients and comparing it with a five-group DRE-based T classification (cT1c vs cT2a vs cT2b vs cT2c vs cT3), but the overlap between the 95% confidence intervals of the models remained. The main limitation is the short follow-up.

CONCLUSIONS

We described an alternative mpMRI-based T staging for prediction of early BCR after RP for PCa. Our results need to be validated externally before they can be applied in clinical practice.

PATIENT SUMMARY

At present, digital rectal examination of the prostate is used to stage prostate cancer. We developed an alternative model for staging that uses information from magnetic resonance imaging (MRI) scans to predict cancer outcomes for men undergoing surgical removal of the prostate.

Multiparametric MRI for Staging of Prostate Cancer: A Multicentric Analysis of Predictive Factors to Improve Identification of Extracapsular Extension before Radical Prostatectomy

Simple Summary

In this multicentric study, we tested the accuracy of multiparametric magnetic resonance imaging (mpMRI) in detecting extracapsular extension (ECE) out of the prostate in order to plan surgical sparing of neurovascular bundles in radical prostatectomy. Univariate and multivariate logistic regression analyses were performed to identify other risk factors for ECE. We found that it has a good ability to exclude extracapsular extension but a poor ability to identify it correctly. Risk factors other than mpMRI that predicted ECE were as follows: prostatic specific antigen, digital rectal examination, ratio of positive cores, and biopsy grade group. We suggest that using mpMRI exclusively should not be recommended to decide on surgical approaches.

Abstract

The correct identification of extracapsular extension (ECE) of prostate cancer (PCa) on multiparametric magnetic resonance imaging (mpMRI) is crucial for surgeons in order to plan the nerve-sparing approach in radical prostatectomy. Nerve-sparing strategies allow for better outcomes in preserving erectile function and urinary continence, notwithstanding this can be penalized with worse oncologic results. The aim of this study was to assess the ability of preoperative mpMRI to predict ECE in the final prostatic specimen (PS) and identify other possible preoperative predictive factors of ECE as a secondary end-point. We investigated a database of two high-volume hospitals to identify men who underwent a prostate biopsy with a pre-biopsy mpMRI and a subsequent RP. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of mpMRI in predicting ECE were calculated. A univariate analysis was performed to find the association between image staging and pathological staging. A multivariate logistic regression was performed to investigate other preoperative predictive factors. A total of 1147 patients were selected, and 203 out of the 1147 (17.7%) patients were classified as ECE according to the mpMRI. ECE was reported by pathologists in 279 out of the 1147 PS (24.3%). The PPV was 0.58, the NPV was 0.72, the sensitivity was 0.32, and the specificity was 0.88. The multivariate analysis found that PSA (OR 1.057, C.I. 95%, 1.016–1.100, p = 0.006), digital rectal examination (OR 0.567, C.I. 95%, 0.417–0.770, p = 0.0001), ratio of positive cores (OR 9.687, C.I. 95%, 3.744–25.006, p = 0.0001), and biopsy grade in prostate biopsy (OR 1.394, C.I. 95%, 1.025–1.612, p = 0.0001) were independent factors of ECE. The mpMRI has a great ability to exclude ECE, notwithstanding that low sensitivity is still an important limitation of the technique.

Assessing the impact of MRI based diagnostics on pre-treatment disease classification and prognostic model performance in men diagnosed with new prostate cancer from an unscreened population

Introduction

Pre-treatment risk and prognostic groups are the cornerstone for deciding management in non-metastatic prostate cancer. All however, were developed in the pre-MRI era. Here we compared categorisation of cancers using either only clinical parameters or with MRI enhanced information in men referred for suspected prostate cancer from an unscreened population.

Patient and methods

Data from men referred from primary care to our diagnostic service and with both clinical (digital rectal examination [DRE] and systematic biopsies) and MRI enhanced attributes (MRI stage and combined systematic/targeted biopsies) were used for this study. Clinical vs MRI data were contrasted for clinico-pathological and risk group re-distribution using the European Association of Urology (EAU), American Urological Association (AUA) and UK National Institute for Health Care Excellence (NICE) Cambridge Prognostic Group (CPG) models. Differences were retrofitted to a population cohort with long-term prostate cancer mortality (PCM) outcomes to simulate impact on model performance. We further contrasted individualised overall survival (OS) predictions using the Predict Prostate algorithm.

Results

Data from 370 men were included (median age 66y). Pre-biopsy MRI stage reassignments occurred in 7.8% (versus DRE). Image-guided biopsies increased Grade Group 2 and ≥ Grade Group 3 assignments in 2.7% and 2.9% respectively. The main change in risk groups was more high-risk cancers (6.2% increase in the EAU and AUA system, 4.3% increase in CPG4 and 1.9% CPG5). When extrapolated to a historical population-based cohort (n = 10,139) the redistribution resulted in generally lower concordance indices for PCM. The 5-tier NICE-CPG system outperformed the 4-tier AUA and 3-tier EAU models (C Index 0.70 versus 0.65 and 0.64). Using an individualised prognostic model, changes in predicted OS were small (median difference 1% and 2% at 10- and 15-years’ respectively). Similarly, estimated treatment survival benefit changes were minimal (1% at both 10- and 15-years’ time frame).

Conclusion

MRI guided diagnostics does change pre-treatment risk groups assignments but the overall prognostic impact appears modest in men referred from unscreened populations. Particularly, when using more granular tiers or individualised prognostic models. Existing risk and prognostic models can continue to be used to counsel men about treatment option until long term survival outcomes are available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09955-w.

More than Meets the Eye: Using Textural Analysis and Artificial Intelligence as Decision Support Tools in Prostate Cancer Diagnosis—A Systematic Review

(1) Introduction: Multiparametric magnetic resonance imaging (mpMRI) is the main imagistic tool employed to assess patients suspected of harboring prostate cancer (PCa), setting the indication for targeted prostate biopsy. However, both mpMRI and targeted prostate biopsy are operator dependent. The past decade has been marked by the emerging domain of radiomics and artificial intelligence (AI), with extended application in medical diagnosis and treatment processes. (2) Aim: To present the current state of the art regarding decision support tools based on texture analysis and AI for the prediction of aggressiveness and biopsy assistance. (3) Materials and Methods: We performed literature research using PubMed MeSH, Scopus and WoS (Web of Science) databases and screened the retrieved papers using PRISMA principles. Articles that addressed PCa diagnosis and staging assisted by texture analysis and AI algorithms were included. (4) Results: 359 papers were retrieved using the keywords “prostate cancer”, “MRI”, “radiomics”, “textural analysis”, “artificial intelligence”, “computer assisted diagnosis”, out of which 35 were included in the final review. In total, 24 articles were presenting PCa diagnosis and prediction of aggressiveness, 7 addressed extracapsular extension assessment and 4 tackled computer-assisted targeted prostate biopsies. (5) Conclusions: The fusion of radiomics and AI has the potential of becoming an everyday tool in the process of diagnosis and staging of the prostate malignancies.

Preoperative MRI PI-RADS scores are associated with prostate cancer upstaging on surgical pathology

INTRODUCTION

Prostate Imaging Reporting and Data System (PI-RADS) scores can help identify clinically significant prostate cancer and improve patient selection for prostate biopsies. However, the role of PI-RADS scores in patients already diagnosed with prostate cancer remains unclear. The purpose of this study was to evaluate the association of PI-RADS scores with prostate cancer upstaging. Upstaging on final pathology harbors a higher risk for biochemical recurrence with important implications for additional treatments, morbidity, and mortality.

METHODS

All patients from a single high-volume institution who underwent a prostate multiparametric magnetic resonance imaging and radical prostatectomy between 2016 and 2020 were included in this retrospective analysis. Univariable and multivariable analyses were conducted to investigate potential associations with upstaging events, defined by pT3, pT4, or N1 on final pathology. A logistic regression model was constructed for the prediction of upstaging events based on PI-RADS score, prostate-specific antigen density (PSA-D), and biopsy Gleason grade groups. We built receiver operative characteristic (ROC) curves to measure the area under the curve of different predictive models.

RESULTS

Two hundred and ninety-four patients were included in the final analysis. Upstaging events occurred in 137 (46.5%) of patients. On univariable analysis, patients who were upstaged on final pathology had significantly higher PI-RADS scores (odds ratio [OR] 2.34 95% confidence interval [CI] 1.64-3.40, p < 0.001) but similar PSA-D (OR 2.70 95% 0.94-8.43, p = 0.188) compared with patients who remained pT1 or pT2 on final pathology. On multivariable analysis, PI-RADS remained independently significantly associated with upstaging, suggesting it is an independent risk predictor for upstaging. Lymph node metastasis only occurred in patients with PI-RADS 4 or 5 lesions (n = 15). Our model using PSA-D, biopsy Gleason grade, and PI-RADS had a predictive AUC of 0.69 for upstaging events, an improvement from 0.59 using biopsy Gleason grade alone.

CONCLUSION

PI-RADS scores are independent predictors for upstaging events and may play an important role in forecasting biochemical recurrence and lymph node metastasis. Modern nomograms should be updated to include PI-RADS to predict lymph node metastases and the likelihood of biochemical recurrence more accurately.

Artificial intelligence is a promising prospect for the detection of prostate cancer extracapsular extension with mpMRI: a two-center comparative study

PURPOSE

A balance between preserving urinary continence as well as sexual potency and achieving negative surgical margins is of clinical relevance while implementary difficulty. Accurate detection of extracapsular extension (ECE) of prostate cancer (PCa) is thus crucial for determining appropriate treatment options. We aimed to develop and validate an artificial intelligence (AI)-based tool for detecting ECE of PCa using multiparametric magnetic resonance imaging (mpMRI).

METHODS

Eight hundred and forty nine consecutive PCa patients who underwent mpMRI and prostatectomy without previous radio- or hormonal therapy from two medical centers were retrospectively included. The AI tool was built on a ResNeXt network embedded with a spatial attention map of experts' prior knowledge (PAGNet) from 596 training patients. Model validation was performed in 150 internal and 103 external patients. Performance comparison was made between AI, two experts using a criteria-based ECE grading system, and expert-AI interaction.

RESULTS

An index PAGNet model using a single-slice image yielded the highest areas under the receiver operating characteristic curve (AUC) of 0.857 (95% confidence interval [CI], 0.827-0.884), 0.807 (95% CI, 0.735-0.867), and 0.728 (95% CI, 0.631-0.811) in training, internal, and external validation data, respectively. The performance of two experts (AUC, 0.632 to 0.741 vs 0.715 to 0.857) was lower (paired comparison, all p values < 0.05) than that of AI assessment. When experts' interpretations were adjusted by AI assessments, the performance of two experts was improved.

CONCLUSION

Our AI tool, showing improved accuracy, offers a promising alternative to human experts for ECE staging using mpMRI.

External validation of the Memorial Sloan Kettering Cancer Centre and Briganti nomograms for the prediction of lymph node involvement of prostate cancer using clinical stage assessed by magnetic resonance imaging

OBJECTIVES

To evaluate the impact of using clinical stage assessed by multiparametric magnetic resonance imaging (mpMRI) on the performance of two established nomograms for the prediction of pelvic lymph node involvement (LNI) in patients with prostate cancer.

PATIENTS AND METHODS

Patients undergoing robot-assisted extended pelvic lymph node dissection (ePLND) from 2015 to 2019 at three teaching hospitals were retrospectively evaluated. Risk of LNI was calculated four times for each patient, using clinical tumour stage (T-stage) assessed by digital rectal examination (DRE) and by mpMRI, in the Memorial Sloan Kettering Cancer Centre (MSKCC; 2018) and Briganti (2012) nomograms. Discrimination (area under the curve [AUC]), calibration, and the net benefit of these four strategies were assessed and compared.

RESULTS

A total of 1062 patients were included, of whom 301 (28%) had histologically proven LNI. Using DRE T-stage resulted in AUCs of 0.71 (95% confidence interval [CI] 0.70-0.72) for the MSKCC and 0.73 (95% CI 0.72-0.74) for the Briganti nomogram. Using mpMRI T-stage, the AUCs were 0.72 (95% CI 0.71-0.73) for the MSKCC and 0.75 (95% CI 0.74-0.76) for the Briganti nomogram. mpMRI T-stage resulted in equivalent calibration compared with DRE T-stage. Combined use of mpMRI T-stage and the Briganti 2012 nomogram was shown to be superior in terms of AUC, calibration, and net benefit. Use of mpMRI T-stage led to increased sensitivity for the detection of LNI for all risk thresholds in both models, countered by a decreased specificity, compared with DRE T-stage.

CONCLUSION

T-stage as assessed by mpMRI is an appropriate alternative for T-stage assessed by DRE to determine nomogram-based risk of LNI in patients with prostate cancer, and was associated with improved model performance of both the MSKCC 2018 and Briganti 2012 nomograms.