Sensitivity of multiparametric MRI and targeted biopsy for detection of adverse pathologies (Cribriform gleason pattern 4 and intraductal carcinoma): Correlation of detected and missed prostate cancer foci with whole mount histopathology

Utility of tumor diameter-to-prostate volume ratio for predicting the outcome of magnetic resonance imaging/transrectal ultrasound fusion-targeted biopsy

OBJECTIVES

To assess the impact of the tumor diameter-to-prostate volume ratio (TD/PV) on predicting prostate cancer (PCa) and clinically significant (cs) -PCa in magnetic resonance imaging (MRI) /transrectal ultrasound (TRUS) fusion-targeted biopsy based on prostate imaging-reporting and data system (PI-RADS) findings in MRI.

MATERIALS AND METHODS

Patients who underwent MRI/TRUS fusion-targeted biopsy for PI-RADS version 2.1 categories 3-5 lesions between 2017 and 2023 were retrospectively reviewed. TD/PV was calculated by dividing the tumor diameter by the total prostate volume. csPCa was defined as a Gleason score of ≥ 3 + 4. Univariable and multivariable logistic regression analyses were used to develop predictive nomograms for PCa and csPCa. A receiver operating characteristic curve was constructed to evaluate the predictive ability of the factors using the area under the curve (AUC).

RESULTS

A total of 565 patients were analyzed; the AUC of TD/PV was significantly superior to those of the prostate-specific antigen (PSA), tumor diameter, PSA density, and PI-RADS for predicting PCa (AUC: 0.840, P < 0.05) and csPCa (AUC: 0.819, P < 0.05). Multivariable analyses showed that TD/PV is a significant predictive factor for PCa and csPCa in MRI/TRUS fusion-targeted biopsy (P < 0.05). The predictive nomograms combining TD/PV and PI-RADS category were constructed and their AUCs for predicting PCa and csPCa were 0.861 and 0.845, respectively.

CONCLUSIONS

In this retrospective analysis, prediction of PCa and csPCa on MRI/TRUS fusion-targeted biopsy was improved when TD/PV was combined with PI-RADS category.

Diagnostic accuracy of multiparametric MRI for detecting unconventional prostate cancer histology: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Accurate detection of unconventional histologies (UH) in prostate cancer (PCa) is crucial for treatment planning and prognosis. This systematic review and meta-analysis aimed to evaluate the accuracy of multiparametric magnetic resonance imaging (mpMRI) in detecting UH on prostatectomy, particularly cribriform architecture (CA) and intraductal carcinoma (IDC-P), in patients with localized PCa.

METHODS

A literature search was conducted in major databases for studies published after 2000. Seventeen articles fulfilled the inclusion criteria and were eligible for qualitative analysis. Five studies met the inclusion criteria for meta-analysis.

RESULTS

The pooled sensitivity and specificity of mpMRI (Prostate Imaging Reporting and Data System (PI-RADS) cutoff 3) to detect cribriform architecture were 0.91 and 0.29. The proportion of cribriform lesions increased with higher PI-RADS scores (23.2% for PI-RADS 1-2 to 66.7% for PI-RADS 5). For intraductal carcinoma (IDC-P), two studies found that IDC-P lesions were visible on mpMRI and had lower apparent diffusion coefficient (ADC) values compared to acinar prostate cancer. Four studies evaluating combined CA/IDC-P found sensitivities ranging from 33 to 100%. Lower ADC values were associated with CA/IDC-P in some studies, but not in others. Overall, mpMRI demonstrated promising sensitivity but moderate specificity in detecting these aggressive histological variants, with continued challenges in accurate sampling and characterization of mpMRI.

CONCLUSIONS

mpMRI shows high sensitivity but moderate specificity in detecting cribriform architecture in PCa, especially for high PI-RADS scores. These findings support the use of mpMRI for UH detection, but caution is advised in clinical interpretation. Larger prospective studies are needed to validate these results before routine clinical application. We studied how effective MRI is at identifying different UH of PCa, such as cribriform architecture and intraductal carcinoma. MRI is accurate at detecting these cancers when they are present, but it also produces a significant number of false positives. More research is needed to standardize imaging protocols and histological definition and ensure an accurate diagnosis.

KEY POINTS

Question The accurate detection of unconventional histologies in prostate cancer, particularly cribriform architecture and intraductal carcinoma, is challenging but crucial for treatment planning and prognosis. Findings mpMRI shows high sensitivity (91%) but low specificity (29%) for detecting cribriform architecture, with detection rates increasing proportionally with higher PI-RADS scores. Clinical relevance mpMRI can effectively detect aggressive unconventional histologies in prostate cancer, though its moderate specificity suggests the need for careful interpretation. This aids in risk stratification and treatment planning, potentially improving patient outcomes.

Histopathological evaluation and grading for prostate cancer: current issues and crucial aspects

ABSTRACT

A crucial aspect of prostate cancer grading, especially in low- and intermediate-risk cancer, is the accurate identification of Gleason pattern 4 glands, which includes ill-formed or fused glands. However, there is notable inconsistency among pathologists in recognizing these glands, especially when mixed with pattern 3 glands. This inconsistency has significant implications for patient management and treatment decisions. Conversely, the recognition of glomeruloid and cribriform architecture has shown higher reproducibility. Cribriform architecture, in particular, has been linked to the worst prognosis among pattern 4 subtypes. Intraductal carcinoma of the prostate (IDC-P) is also associated with high-grade cancer and poor prognosis. Accurate identification, classification, and tumor size evaluation by pathologists are vital for determining patient treatment. This review emphasizes the importance of prostate cancer grading, highlighting challenges like distinguishing between pattern 3 and pattern 4 and the prognostic implications of cribriform architecture and intraductal proliferations. It also addresses the inherent grading limitations due to interobserver variability and explores the potential of computational pathology to enhance pathologist accuracy and consistency.

Proposal for an optimised definition of adverse pathology (unfavourable histology) that predicts metastatic risk in prostatic adenocarcinoma independent of grade group and pathological stage

AIMS

Histological grading of prostate cancer is a powerful prognostic tool, but current criteria for grade assignment are not fully optimised. Our goal was to develop and test a simplified histological grading model, based heavily on large cribriform/intraductal carcinoma, with optimised sensitivity for predicting metastatic potential.

METHODS AND RESULTS

Two separate non-overlapping cohorts were identified: a 419-patient post-radical prostatectomy cohort with long term clinical follow-up and a 209-patient post-radical prostatectomy cohort in which all patients had pathologically confirmed metastatic disease. All prostatectomies were re-reviewed for high-risk histological patterns of carcinoma termed 'unfavourable histology'. Unfavourable histology is defined by any classic Gleason pattern 5 component, any large cribriform morphology (> 0.25 mm) or intraductal carcinoma, complex intraluminal papillary architecture, grade 3 stromogenic carcinoma and complex anastomosing cord-like growth. For the outcome cohort, Kaplan-Meier analysis compared biochemical recurrence, metastasis and death between subjects with favourable and unfavourable histology, stratified by pathological stage and grade group. Multivariable Cox proportional hazards models evaluated adding unfavourable histology to the Memorial Sloan Kettering Cancer Center (MSKCC) post-prostatectomy nomogram and stratification by percentage of unfavourable histology. At 15 years unfavourable histology predicted biochemical recurrence, with sensitivity of 93% and specificity of 88%, metastatic disease at 100 and 48% and death at 100 and 46%. Grade group 2 prostate cancers with unfavourable histology were associated with metastasis independent of pathological stage, while those without had no risk. Histological models for prediction of metastasis based on only large cribriform/intraductal carcinoma or increasing diameter of cribriform size improved specificity, but with lower sensitivity. Multivariable Cox proportional hazards models demonstrated that unfavourable histology significantly improved discriminatory power of the MSKCC post-prostatectomy nomogram for biochemical failure (likelihood ratio test P < 0.001). In the retrospective review of a separate RP cohort in which all patients had confirmed metastatic disease, none had unequivocal favourable histology.

CONCLUSIONS

Unfavourable histology at radical prostatectomy is associated with metastatic risk, predicted adverse outcomes better than current grading and staging systems and improved the MSKCC post-prostatectomy nomogram. Most importantly, unfavourable histology stratified grade group 2 prostate cancers into those with and without metastatic potential, independent of stage. While unfavourable histology is driven predominantly by large cribriform/intraductal carcinoma, the recognition and inclusion of other specific architectural patterns add to the sensitivity for predicting metastatic disease. Moreover, a simplified dichotomous model improves communication and could increase implementation.

Comparison of Multiparametric MRI-targeted and Systematic Biopsies for Detection of Cribriform and Intraductal Carcinoma Prostate Cancer

Background Intraductal carcinoma (IDC) and invasive cribriform (Cr) subtypes of prostate cancer (PCa) are an indication of aggressiveness, but the evidence regarding whether MRI can be used to detect Cr/IDC-pattern PCa is contradictory. Purpose To compare the detection of Cr/IDC-pattern PCa at multiparametric MRI (mpMRI)-targeted biopsy versus systematic biopsy in biopsy-naive men at risk for PCa. Materials and Methods This study was a secondary analysis of a prospective randomized controlled trial that recruited participants with a clinical suspicion of PCa between April 2017 and November 2019 at five centers. Participants were randomized 1:1 to either the MRI arm or the systematic biopsy arm. Targeted biopsy was performed in participants with a Prostate Imaging Reporting and Data System score of at least 3. MRI features were recorded, and biopsy slides and prostatectomy specimens were reviewed for the presence or absence of Cr/IDC histologic patterns. Comparison of Cr/IDC patterns was performed using generalized linear mixed modeling. Results A total of 453 participants were enrolled, with 226 in the systematic biopsy arm (median age, 65 years [IQR, 59-70 years]; 196 biopsies available for assessment) and 227 in the mpMRI-targeted biopsy arm (median age, 67 years [IQR, 60-72 years]; 132 biopsies available for assessment). Identification of Cr/IDC PCa was lower in the systematic biopsy arm compared with the mpMRI arm (31 of 196 biopsies [16%] vs 33 of 132 biopsies [25%]; P = .01). No evidence of a difference in mean cancer core length (CCL) (11.3 mm ± 4.4 vs 9.7 mm ± 4.5; P = .09), apparent diffusion coefficient (685 µm2/sec ± 178 vs 746 µm2/sec ± 245; P = .52), or dynamic contrast-enhanced positivity (27 [82%] vs 37 [90%]; P = .33) for clinically significant PCa (csPCa) was observed between participants with or without Cr/IDC disease in the MRI arm. Cr/IDC-positive histologic patterns overall had a higher mean CCL compared with Cr/IDC-negative csPCa (11.1 mm ± 4.4 vs 9.2 mm ± 4.1; P = .009). Conclusion MRI-targeted biopsy showed increased detection of Cr/IDC histologic patterns compared with systematic biopsy. Clinical trial registration no. NCT02936258 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Scialpi and Martorana in this issue.

Exploring the potential of ex-vivo 7-T magnetic resonance imaging on patients with clinically significant prostate cancer: visibility and size perspective

Background

Despite progress in multiparametric magnetic resonance imaging (MRI), issues of prostate cancer invisibility and underestimated tumor burden persist. This study investigates the potential of an ultra-high field MRI at 7-T in an ex-vivo setting to address these limitations.

Methods

This prospective study included 54 tumors from 20 treatment-naïve clinically significant prostate cancer patients, confirmed by biopsy, despite negative findings on preoperative 3-T MRI. Ex-vivo 7-T MRI of resected prostates was performed, with assessment on tumor visibility and size. Factors influencing visibility were analyzed using logistic regression analyses.

Results

Tumor visibility was confirmed in 80% of patients, and 48% of all tumors on ex-vivo imaging. Gleason pattern 4 percentage (odds ratio 1.09) and tumor size on pathology (odds ratio 1.36) were significantly associated with visibility (P < 0.05). Mean MRI-visible and invisible tumor sizes were 10.5 mm and 5.3 mm, respectively. The size discrepancy between MRI and pathology was 2.7 mm.

Conclusion

Tumor visibility on ex-vivo 7-T MRI was influenced by tumor grade and size. The notable tumor visibility initially overlooked on 3-T MRI, along with small size discrepancy with pathology, suggests potential improvements in resolution.

Limitations of Prostate Biopsy in Detection of Cribriform and Intraductal Prostate Cancer

BACKGROUND

The presence of cribriform morphology and intraductal carcinoma (IDC) in prostate biopsies and radical prostatectomy specimens is an adverse prognostic feature that can be used to guide treatment decisions.

OBJECTIVE

To assess how accurately biopsies can detect cribriform morphology and IDC cancer by examining matched biopsy and prostatectomy samples.

DESIGN, SETTING, AND PARTICIPANTS

Patients who underwent radical prostatectomy at The Princess Margaret Cancer Centre between January 2015 and December 2022 and had cribriform morphology and/or IDC in the surgical specimen were included in the study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used detection sensitivity to evaluate the level of agreement between biopsy and prostatectomy samples regarding the presence of cribriform morphology and IDC.

RESULTS AND LIMITATIONS

Of the 287 men who underwent radical prostatectomy, 241 (84%) had cribriform morphology and 161 (56%) had IDC on final pathology. The sensitivity of prostate biopsy, using radical prostatectomy as the reference, was 42.4% (95% confidence interval [CI] 36-49%) for detection of cribriform morphology and 44.1% (95% CI 36-52%) for detection of IDC. The sensitivity of prostate biopsy for detection of either IDC or cribriform morphology was 52.5% (95% CI 47-58%). Among patients who underwent multiparametric magnetic resonance imaging-guided biopsies, the sensitivity was 54% (95% CI 39-68%) for detection of cribriform morphology and 37% (95% CI 19-58%) for detection of IDC.

CONCLUSIONS

Biopsy has low sensitivity for detecting cribriform morphology and IDC. These limitations should be incorporated into clinical decision-making. Biomarkers for better detection of these histological patterns are needed.

PATIENT SUMMARY

Prostate biopsy is not an accurate method for detecting two specific types of prostate cancer cells, called cribriform pattern and intraductal prostate cancer, which are associated with unfavorable prognosis.

Is cribriform pattern in prostate biopsy a risk factor for metastatic disease on 68Ga-PSMA-11 PET/CT?

INTRODUCTION

Cribriform growth pattern (CP) in prostate cancer (PCa) has been associated with different unfavourable oncological outcomes. This study addresses if CP in prostate biopsies is an independent risk factor for metastatic disease on PSMA PET/CT.

METHODS

Treatment-naive patients with ISUP GG ≥ 2 staged with 68Ga-PSMA-11 PET/CT diagnosed from 2020 to 2021 were retrospectively enrolled. To test if CP in biopsies was an independent risk factor for metastatic disease on 68Ga-PSMA PET/CT, regression analyses were performed. Secondary analyses were performed in different subgroups.

RESULTS

A total of 401 patients were included. CP was reported in 252 (63%) patients. CP in biopsies was not an independent risk factor for metastatic disease on the 68Ga-PSMA PET/CT (p = 0.14). ISUP grade group (GG) 4 (p = 0.006), GG 5 (p = 0.003), higher PSA level groups per 10 ng/ml until > 50 (p-value between 0.02 and > 0.001) and clinical EPE (p > 0.001) were all independent risk factors. In the subgroups with GG 2 (n = 99), GG 3 (n = 110), intermediate-risk group (n = 129) or the high-risk group (n = 272), CP in biopsies was also not an independent risk factor for metastatic disease on 68Ga-PSMA PET/CT. If the EAU guideline recommendation for performing metastatic screening was applied as threshold for PSMA PET/CT imaging, in 9(2%) patients, metastatic disease was missed, and 18% fewer PSMA PET/CT would have been performed.

CONCLUSION

This retrospective study found that CP in biopsies was not an independent risk factor for metastatic disease on 68Ga-PSMA PET/CT.

Nomogram Models for Distinguishing Intraductal Carcinoma of the Prostate From Prostatic Acinar Adenocarcinoma Based on Multiparametric Magnetic Resonance Imaging

OBJECTIVE

To compare multiparametric magnetic resonance imaging (MRI) features of intraductal carcinoma of the prostate (IDC-P) with those of prostatic acinar adenocarcinoma (PAC) and develop prediction models to distinguish IDC-P from PAC and IDC-P with a high proportion (IDC ≥ 10%, hpIDC-P) from IDC-P with a low proportion (IDC < 10%, lpIDC-P) and PAC.

MATERIALS AND METHODS

One hundred and six patients with hpIDC-P, 105 with lpIDC-P and 168 with PAC, who underwent pretreatment multiparametric MRI between January 2015 and December 2020 were included in this study. Imaging parameters, including invasiveness and metastasis, were evaluated and compared between the PAC and IDC-P groups as well as between the hpIDC-P and lpIDC-P subgroups. Nomograms for distinguishing IDC-P from PAC, and hpIDC-P from lpIDC-P and PAC, were made using multivariable logistic regression analysis. The discrimination performance of the models was assessed using the receiver operating characteristic area under the curve (ROC-AUC) in the sample, where the models were derived from without an independent validation sample.

RESULTS

The tumor diameter was larger and invasive and metastatic features were more common in the IDC-P than in the PAC group (P < 0.001). The distribution of extraprostatic extension (EPE) and pelvic lymphadenopathy was even greater, and the apparent diffusion coefficient (ADC) ratio was lower in the hpIDC-P than in the lpIDC-P group (P < 0.05). The ROC-AUCs of the stepwise models based solely on imaging features for distinguishing IDC-P from PAC and hpIDC-P from lpIDC-P and PAC were 0.797 (95% confidence interval, 0.750-0.843) and 0.777 (0.727-0.827), respectively.

CONCLUSION

IDC-P was more likely to be larger, more invasive, and more metastatic, with obviously restricted diffusion. EPE, pelvic lymphadenopathy, and a lower ADC ratio were more likely to occur in hpIDC-P, and were also the most useful variables in both nomograms for predicting IDC-P and hpIDC-P.