Determination of the Association Between T2-weighted MRI and Gleason Sub-pattern: A Proof of Principle Study

Is prostatic adenocarcinoma with cribriform architecture more difficult to detect on prostate MRI?

BACKGROUND

Cribriform (CBFM) pattern on prostate biopsy has been implicated as a predictor for high-risk features, potentially leading to adverse outcomes after definitive treatment. This study aims to investigate whether the CBFM pattern containing prostate cancers (PCa) were associated with false negative magnetic resonance imaging (MRI) and determine the association between MRI and histopathological disease burden.

METHODS

Patients who underwent multiparametric magnetic resonance imaging (mpMRI), combined 12-core transrectal ultrasound (TRUS) guided systematic (SB) and MRI/US fusion-guided biopsy were retrospectively queried for the presence of CBFM pattern at biopsy. Biopsy cores and lesions were categorized as follows: C0 = benign, C1 = PCa with no CBFM pattern, C2 = PCa with CBFM pattern. Correlation between cancer core length (CCL) and measured MRI lesion dimension were assessed using a modified Pearson correlation test for clustered data. Differences between the biopsy core groups were assessed with the Wilcoxon-signed rank test with clustering.

RESULTS

Between 2015 and 2022, a total of 131 consecutive patients with CBFM pattern on prostate biopsy and pre-biopsy mpMRI were included. Clinical feature analysis included 1572 systematic biopsy cores (1149 C0, 272 C1, 151 C2) and 736 MRI-targeted biopsy cores (253 C0, 272 C1, 211 C2). Of the 131 patients with confirmed CBFM pathology, targeted biopsy (TBx) alone identified CBFM in 76.3% (100/131) of patients and detected PCa in 97.7% (128/131) patients. SBx biopsy alone detected CBFM in 61.1% (80/131) of patients and PCa in 90.8% (119/131) patients. TBx and SBx had equivalent detection in patients with smaller prostates (p = 0.045). For both PCa lesion groups there was a positive and significant correlation between maximum MRI lesion dimension and CCL (C1 lesions: p < 0.01, C2 lesions: p < 0.001). There was a significant difference in CCL between C1 and C2 lesions for T2 scores of 3 and 5 (p ≤ 0.01, p ≤ 0.01, respectively) and PI-RADS 5 lesions (p ≤ 0.01), with C2 lesions having larger CCL, despite no significant difference in MRI lesion dimension.

CONCLUSIONS

The extent of disease for CBFM-containing tumors is difficult to capture on mpMRI. When comparing MRI lesions of similar dimensions and PIRADS scores, CBFM-containing tumors appear to have larger cancer yield on biopsy. Proper staging and planning of therapeutic interventions is reliant on accurate mpMRI estimation. Special considerations should be taken for patients with CBFM pattern on prostate biopsy.

The cribriform morphology impairs Gleason 7 prostate cancer lesion detection on multiparametric magnetic resonance imaging

BACKGROUND

Prostate multiparametric magnetic resonance imaging (mpMRI) is a useful tool for the detection of tumor lesions however, some clinically significant lesions are still missed. We determined whether the cribriform pattern has an effect on lesion detection in mpMRI.

METHODS

We reviewed the single-institution database of the patients who underwent mpMRI before radical prostatectomy. We included the patients only with the Gleason 7 final pathology of open radical prostatectomy with curative intent between 2016 and 2021. Prostatectomy mappings according to the 16-sector map and cribriform patterns were re-evaluated by two genitourinary pathologists. Prostate mpMRIs were read by two genitourinary radiologists. If the index and nonindex lesions in pathology mapping were matched with mpMRI as Prostate Imaging Reporting and Data System-3 or higher, it was defined as detectable. We compared the detection rates of lesions with and without cribriform morphology. In regression analysis, we also assessed the factors affecting the detectability of prostate cancer lesions.

RESULTS

A total of 120 patients and 157 lesions were included in our study. While 52 of 83 cribriform pattern positive lesions could be detected in mpMRI, 59 of 74 cribriform pattern negative lesions could be detected (62.7% vs. 79.7%, respectively, p = 0.019). The lesions were also distributed homogeneously according to diameters and analyzed separately. All lesions between 21 and 30 mm with the negative cribriform pattern were detected on mpMRI. However, only 77.8% of cribriform pattern positive lesions between 21 and 30 mm could be detected (p = 0.034). The Higher D'Amico risk group and the absence of cribriform morphology were independent predictors for the lesion detection on mpMRI.

CONCLUSION

The presence of cribriform pattern in Gleason 7 prostate cancer lesions decreases the lesion detection rate of mpMRI.

Clinical outcomes of intraductal carcinoma or cribriform in radical prostatectomy specimens of men opting for active surveillance: data from the PRIAS-JAPAN study

BACKGROUND

Among early stage prostate cancer patients, intraductal carcinoma of the prostate (IDC-P) and invasive cribriform are key prognostic factors; however, their presence and clinical significance following active surveillance (AS) are unknown. In men who opted for AS, we aimed to examine the presence and impact of IDC-P or cribriform, utilizing radical prostatectomy (RP) specimens.

METHODS

We re-reviewed 137 RP specimens available in the PRIAS-JAPAN prospective cohort between January 2010 and September 2020. We assessed the presence of IDC-P or cribriform, and compared the patients' characteristics and prostate-specific antigen (PSA) recurrence-free survival after RP between groups with and without IDC-P or cribriform. In addition, we examined the predictive factors associated with IDC-P or cribriform.

RESULTS

The percentage of patients with IDC-P or cribriform presence was 34.3% (47 patients). IDC-P or cribriform pattern was more abundant in the higher Gleason grade group in RP specimens (P < 0.001). The rates of PSA recurrence-free survival were significantly lower in the IDC-P or cribriform groups than in those without them (log rank P = 0.0211). There was no association between IDC-P or cribriform on RP with the Prostate Imaging-Reporting and Data System (PI-RADS) 4,5 score on magnetic resonance imaging (MRI) before RP even with adjustments for other covariates (OR, 1.43; 95% confidence interval [CI] 0.511-3.980, P = 0.497).

CONCLUSIONS

IDC-P or cribriform comprised approximately one-third of all RP specimens in men who underwent RP following AS, confirming their prognostic significance.

Differentiating prostate cancer from benign prostatic hyperplasia using whole-lesion histogram and texture analysis of diffusion- and T2-weighted imaging

Background

To explore the usefulness of analyzing histograms and textures of apparent diffusion coefficient (ADC) maps and T2-weighted (T2W) images to differentiate prostatic cancer (PCa) from benign prostatic hyperplasia (BPH) using histopathology as the reference.

Methods

Ninety patients with PCa and 112 patients with BPH were included in this retrospective study. Differences in whole-lesion histograms and texture parameters of ADC maps and T2W images between PCa and BPH patients were evaluated using the independent samples t-test. The diagnostic performance of ADC maps and T2W images in being able to differentiate PCa from BPH was assessed using receiver operating characteristic (ROC) curves.

Results 

The mean, median, 5^th, and 95^th percentiles of ADC values in images from PCa patients were significantly lower than those from BPH patients (p < 0.05). Significant differences were observed in the means, standard deviations, medians, kurtosis, skewness, and 5^th percentile values of T2W image between PCa and BPH patients (p < 0.05). The ADC_5th showed the largest AUC (0.906) with a sensitivity of 83.3 % and specificity of 89.3 %. The diagnostic performance of the T2W image histogram and texture analysis was moderate and had the largest AUC of 0.634 for T2W_Kurtosis with a sensitivity and specificity of 48.9% and 79.5 %, respectively. The diagnostic performance of the combined ADC_5th & T2W_Kurtosis parameters was also similar to that of the ADC_5th & ADC_{Diff−Variance}.

Conclusions

Histogram and texture parameters derived from the ADC maps and T2W images for entire prostatic lesions could be used as imaging biomarkers to differentiate PCa and BPH biologic characteristics, however, histogram parameters outperformed texture parameters in the diagnostic performance.

The visibility of prostate cancer concerning underlying histopathological variances: A single-center multiparametric magnetic resonance imaging study

PURPOSE

To investigate whether prostate cancer (PCa) lesions regarding histopathological composition exhibit different morphological features on multiparametric prostate MRI (mpMRI).

METHODS

We investigated men with PCa with available mpMRI and whole-mount specimens between June 2015 to December 2020.The acquisition protocol consistent with the Prostate Imaging Reporting and Data System (PI-RADS). Two observers evaluated the images following the PI-RADS v2.1. guideline before biopsy and radical prostatectomy. The discrepancies were resolved in a joint meeting. A genitourinary pathologist reviewed the whole-digitalized mount specimens, and the lesions with Gleason score of 7 and above (3 + 4 and above), and/or cancers with a maximum diameter of 6 mm and more, and/or extraprostatic extension were accepted as clinically significant PCa. The PI-RADS scores and the diameter of the clinically significant PCa on mpMRI concerning histopathological components (i.e., cribriform component, intraductal pattern, or without cribriform component or intraductal pattern) were investigated. The clinically significant PCa foci with PI-RADS score <3 was accepted as an invisible lesion on mpMRI.

RESULTS

In all, 58 men with a total of 112 clinically significant PCa foci, were enrolled in the study. The intraductal pattern, cribriform pattern, or none of these patterns were observed in 28/112 (25 %), 43/112 (38.05 %), and 41/112 (36.60 %) tumor foci. Six out of 28 (21.42 %), 17/43 (39.53 %), and 18/41 (42.8 %) foci with an intraductal pattern, cribriform component, or without any of them, respectively, were invisible on mpMRI (P = 0.111).

CONCLUSION

Though it was not reached a statistical significance, clinically significant PCa with the cribriform component and without any intraductal or cribriform component are more likely to manifests mpMRI invisible foci than the intraductal pattern. Further multi-center studies are warranted to precisely elucidate mpMRI features of PCa regarding histopathological composition.

Simplified PI-RADS (S-PI-RADS) for biparametric MRI to detect and manage prostate cancer: What urologists need to know

Biparametric magnetic resonance imaging (bpMRI) of the prostate has emerged as an alternative to multiparametric MRI (mpMRI) for the detection of clinically significant prostate cancer (csPCa). However, while the Prostate Imaging Reporting and Data System (PI-RADS) is widely known for mpMRI, a proper PI-RADS for bpMRI has not yet been adopted. In this review, we report the current status and the future directions of bpMRI, and propose a simplified PI-RADS (S-PI-RADS) that could help radiologists and urologists in the detection and management of PCa.

MRI-targeted prostate biopsy: the next step forward!

Aim

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

Methods

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

Results

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

Conclusion

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

Conspicuity of prostate cancer on multiparametric magnetic resonance imaging: A cross-disciplinary translational hypothesis

Pre-biopsy multiparametric magnetic resonance imaging (mpMRI) has transformed the risk stratification and diagnostic approach for suspected prostate cancer. The majority of clinically significant prostate cancers are visible on pre-biopsy mpMRI, however, there are a subset of significant tumors that are not detected by mpMRI. The radiobiological mechanisms underpinning mpMRI-visibility and invisibility of these cancers remain uncertain. Emerging evidence suggests that mpMRI-visible tumors are enriched with molecular features associated with increased disease aggressivity and poor clinical prognosis, which is supported by short-term endpoints, such as biochemical recurrence following surgery. Furthermore, at the histopathological level, mpMRI-visible tumors appear to exhibit increased architectural and vascular density compared to mpMRI-invisible disease. It seems probable that the genomic, pathological, radiological, and clinical features of mpMRI-visible and mpMRI-invisible prostate cancers are interrelated. Here, we propose a novel cross-disciplinary theory that links genomic and molecular evidence with cellular and histopathological appearances, elucidating both the mpMRI visibility and clinical status of significant prostate cancer.

Historical and contemporary perspectives on cribriform morphology in prostate cancer

The Gleason scoring system is widely used for the grading and prognostication of prostate cancer. A Gleason pattern 4 subtype known as cribriform morphology has now been recognized as an aggressive and often lethal pattern of prostate cancer. The vast majority of published and ongoing prostate cancer studies still do not acknowledge the prognostic differences between various Gleason pattern 4 morphologies. As a result, current treatment recommendations are likely to be imprecise and not tailored towards patients who are most likely to die from the disease. Use of active surveillance for patients with Gleason score 3 + 4 prostate cancer has been suggested. However, the success of such paradigms would require cribriform morphology to be reported at the time of prostate biopsy, as patients harbouring such a pattern are poor candidates for surveillance. To date, only a limited number of studies have described the molecular alterations that occur in the cribriform morphological pattern. Further refinement of prostate cancer grading paradigms to distinguish cribriform from noncribriform Gleason pattern 4 is essential.

Grading of prostate cancer: a work in progress

Grading of prostate cancer has evolved substantially over time, not least because of major changes in diagnostic approach and concomitant shifts from late- to early-stage detection since the adoption of PSA testing from the late 1980s. After the conception of the architecture-based nine-tier Gleason grading system more than 50 years ago, several changes were made in order to increase its prognostic impact, to reduce interobserver variation and to improve concordance between prostate needle biopsy and radical prostatectomy grading. This eventually resulted in the current five-tier grading system, with a much more detailed description of the individual architectural patterns constituting the remaining three Gleason patterns (i.e. grades 3-5). Nevertheless, there is room for improvement. For instance, distinction of common grade 4 subpatterns such as ill-formed and fused glands from the grade 3 pattern is challenging, blurring the division between low-risk patients who could be eligible for deferred therapy and those who need curative therapy. The last few years have witnessed the publication of several studies on the prognostic impact of individual architectural subpatterns showing that, in particular, the cribriform pattern exceeded the prognostic impact of other grade 4 subpatterns. This review provides an overview of the changes in prostate cancer grading over time and provides a thorough description of the various Gleason subpatterns, the current evidence of their prognostic impact and areas of contention. Potential practical ways for improvements of the current grading system are also put forward.

Prostate cancer with cribriform morphology: diagnosis, aggressiveness, molecular pathology and possible relationships with intraductal carcinoma

INTRODUCTION

The Gleason grading system is one of the most important prognostic factors in prostate cancer (PCa). From the 2005 to the 2014 conference organized by the International Society of Urological Pathology (ISUP), the histological criteria for the Gleason patterns were improved, resulting in the shrinkage of the Gleason pattern (GP) 3 and expansion of the GP 4. Areas Covered: Cribriform, fused, ill-defined and glomeruloid glands are part of the morphologic spectrum of the current GP 4. Cribriform, derived from the Latin word cribrum (i.e. sieve), was introduced by Gleason to describe glands composed of a solid sheet with perforations or lumina. Cribriform morphology has a worse prognosis compared with the other, non-cribriform, GP4 morphologies. A practical implication is that a cribriform growth precludes a patient from selecting an active surveillance (AS) protocol. Expert commentary: The presence of these four growth patterns should be incorporated into the current Grade Group (GG) system. Enhancing our understanding of cribriform tumor behavior will lead to correctly identifying and treating those patients that will die because of PCa, while sparing treatment in those who do not require it.

On cribriform prostate cancer

The management of newly diagnosed prostate cancer is challenging because of its heterogeneity in histology, genetics and clinical outcome. The clinical outcome of patients with Gleason score 7 prostate cancer varies greatly. Improving risk assessment in this group is of particular interest, as Gleason score 7 prostate cancer on biopsy is an important clinical threshold for active treatment. Architecturally, four Gleason grade 4 growth patterns are recognized: ill-formed, fused, glomeruloid and cribriform. The aim of this review is to describe the role of cribriform growth in prostate cancer with respect to diagnosis, prognosis and molecular pathology. Secondly, we will discuss clinical applications for cribriform prostate cancer and give recommendations for future research.

MRI in early prostate cancer detection: how to manage indeterminate or equivocal PI-RADS 3 lesions?

This review focuses on indeterminate lesions on prostate magnetic resonance imaging (MRI), assigned as PI-RADS category 3. The prevalence of PI-RADS 3 index lesion in the diagnostic work-up is significant, varying between one in three (32%) to one in five (22%) men, depending on patient cohort of first biopsies, previously negative biopsies, and active surveillance biopsies. A management strategy must be developed for this group of men with an indeterminate suspicion of having clinically significant prostate cancer (csPCa). Currently available data show that the actual prevalence of csPCa after targeted biopsy in PI-RADS 3 lesions vary between patients groups from one in five (21%) to one in six (16%), depending on previous biopsy status. Although this prevalence is lower in comparison to PI-RADS 4 and PI-RADS 5 lesions, still a considerable proportion of men harbor significant disease. Men with such a PI-RADS 3 lesion should therefore be adequately managed. In general, the clinical approach of using a threshold of PI-RADS ≥4 instead of PI-RADS ≥3 to select MRI for targeted biopsies is not supported by data from our explorative literature search using current definitions of csPCa. A possible adaptation to the threshold of PI-RADS ≥4 in combination with other clinical markers could be considered within an active surveillance protocol, where the balance between the individual risk of missing csPCa and the constant process of repeating prostate biopsies is crucial. In the future, improvements in MR imaging and interpretation, combined with molecular biomarkers and multivariate risk models will all be employed in prostate cancer detection and monitoring. These combinations will aid decision-making in challenging circumstances, such as unclear and diagnostic equivocal results for csPCa at early detection.