Presence of invasive cribriform or intraductal growth at biopsy outperforms percentage grade 4 in predicting outcome of Gleason score 3+4=7 prostate cancer

Morphologic patterns observed in prostate biopsy cases with discrepant grade group and molecular risk classification

BACKGROUND

Molecular-based risk classifier tests are increasingly being utilized by urologists and radiation oncologists to guide clinical decision making. The Decipher prostate biopsy test is a 22-gene RNA biomarker assay designed to predict likelihood of high-grade disease at radical prostatectomy and risk of metastasis and mortality. The test provides a risk category of low, intermediate, or high. We investigated histologic features of biopsies in which the Grade Group (GG) and Decipher risk category (molecular risk) were discrepant.

METHODS

Our institutional urologic outcomes database was searched for men who underwent prostate biopsies with subsequent Decipher testing from 2016 to 2020. We defined discrepant GG and molecular risk as either GG1-2 with high Decipher risk category or GG ≥ 3 with low Decipher risk category. The biopsy slide on which Decipher testing was performed was re-reviewed for GG and various histologic features, including % Gleason pattern 4, types of Gleason pattern 4 and 5, other "high risk" features (e.g., complex papillary, ductal carcinoma, intraductal carcinoma [IDC]), and other unusual and often "difficult to grade" patterns (e.g., atrophic carcinoma, mucin rupture, pseudohyperplastic carcinoma, collagenous fibroplasia, foamy gland carcinoma, carcinoma with basal cell marker expression, carcinoma with prominent vacuoles, and stromal reaction). Follow-up data was also obtained from the electronic medical record.

RESULTS

Of 178 men who underwent prostate biopsies and had Decipher testing performed, 41 (23%) had discrepant GG and molecular risk. Slides were available for review for 33/41 (80%). Of these 33 patients, 23 (70%) had GG1-2 (GG1 n = 5, GG2 n = 18) with high Decipher risk, and 10 (30%) had GG ≥ 3 with low Decipher risk. Of the 5 GG1 cases, one case was considered GG2 on re-review; no other high risk features were identified but each case showed at least one of the following "difficult to grade" patterns: 3 atrophic carcinoma, 1 collagenous fibroplasia, 1 carcinoma with mucin rupture, and 1 carcinoma with basal cell marker expression. Of the 18 GG2 high Decipher risk cases, 2 showed GG3 on re-review, 5 showed large cribriform and/or other high risk features, and 10 showed a "difficult to grade" pattern. Of the 10 GG ≥ 3 low Decipher risk cases, 5 had known high risk features including 2 with large cribriform, 1 with IDC, and 1 with Gleason pattern 5.

CONCLUSIONS

In GG1-2 high Decipher risk cases, difficult to grade patterns were frequently seen in the absence of other known high risk morphologic features; whether these constitute true high risk cases requires further study. In the GG ≥ 3 low Decipher risk cases, aggressive histologic patterns such as large cribriform and IDC were observed in half (50%) of cases; therefore, the molecular classifier may not capture all high risk histologic patterns.

Pathologic and Short-Term Oncologic Outcomes of Prostate Cancer Patients Following Transvesical Robot-Assisted Radical Prostatectomy

PURPOSE

To study the pathologic and short-term oncological and survival outcomes following Transvesical Single-Port Robot-Assisted Radical Prostatectomy.

MATERIALS AND METHODS

A retrospective review was performed on prospectively collected data on 169 patients with low and intermediate-risks prostate cancer, who either underwent Single-Port Transvesical or Multi-Port Transperitoneal Radical Prostatectomy by a single surgeon between 2015 and 2022. Preoperative clinicopathologic characteristics, as well as final histopathology outcomes, were compared. Univariate Cox proportional hazard analysis was used to evaluate the impact of the surgical approach on biochemical recurrence-free survival within 12 months.

RESULTS

Single-Port Transvesical and Multi-Port Transperitoneal Robotic Radical Prostatectomy were completed in 85 and 84 patients, respectively. Preoperative clinicopathologic features were similar between the 2 groups. In terms of histopathology outcomes, the 2 groups had identical final Gleason Grades, T stage, as well as the rates of adverse pathological features and positive surgical margins (P = >0.05). Despite the lower median number of nodes in the single-port cohort of 2 (0-5) compared to 6 (4-9) in the multi-port cohort (P = <0.001), there remained no statistically significant difference in the rates of lymph node invasion (P = 0.08). At a median follow-up of 12 months, there were no differences in the biochemical recurrence-free survival rates among both groups (P = 0.38). Univariate Cox proportional hazard analysis did not consider surgical approach to be an independent predictor of biochemical recurrence (HR 0.53, 95%CI 0.13-2.23, P = 0.39).

CONCLUSION

In well-selected patients, single-port transvesical robotic radical prostatectomy provided a similar short-term oncologic control as the multi-port approach with similar surgical margin status and 1-year biochemical recurrence rates.

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.

Clinical Significance of Intraductal Carcinoma of the Prostate After High-Dose Brachytherapy With External Beam Radiation Therapy: A Single Institution Series and an Updated Meta-Analysis

BACKGROUND

We compared oncological outcomes between prostate cancer (PCa) patients with and without intraductal carcinoma of the prostate (IDC-P) after high-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT).

METHODS

We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received HDR-BT with EBRT. Of these, 70 (50.7 %) patients were diagnosed with IDC-P; 68 (49.3 %) patients with acinar adenocarcinoma of prostate. The oncological outcomes, including biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS), were assessed using Kaplan-Meier curves. Additionally, Cox proportional hazards models were used to identify significant prognostic indicators or biochemical recurrence (BCR). Meta-analysis of existing literatures was performed to evaluate the risk of BCR in patients with IDC-P after radiation therapy, compared to those without IDC-P.

RESULTS

Kaplan-Meier curves demonstrated significantly inferior BCRFS and CPFS in patients with IDC-P. Multivariate analysis revealed that IDC-P and Grade Group 5 status were associated with increased BCR risk. in our meta-analysis, IDC-P was associated with BCR (HR = 2.13, P = .003).

CONCLUSION

Amongst the patients who received HDR-BT, patients with IDC-P displayed significantly more rapid disease progression, compared with patients who did not have IDC-P.

Large cribriform glands (> 0.25 mm diameter) as a predictor of adverse pathology in men with Grade Group 2 prostate cancer

AIMS

A recent outcome-based, radical prostatectomy study defined > 0.25 mm diameter to distinguish large versus small cribriform glands, with > 0.25 mm associated with worse recurrence-free survival. This study evaluates whether identification of > 0.25 mm cribriform glands in Grade Group 2 patients at biopsy is associated with adverse pathology at radical prostatectomy.

METHODS AND RESULTS

Tumours containing biopsy slides for 133 patients with Grade Group 2 prostate cancer with subsequent radical prostatectomy were re-reviewed for large cribriform glands (diameter > 0.25 mm). The primary outcome was adverse pathology (Grade Groups 3-5; stage pT3a or greater, or pN1). The secondary outcome was recurrence-free survival. Cribriform pattern was present in 52 of 133 (39%) patients; of these, 16 of 52 (31%) had large cribriform glands and 36 of 52 (69%) had only small cribriform glands. Patients with large cribriform glands had significantly more adverse pathology at radical prostatectomy compared to patients with small cribriform glands and no cribriform glands (large = 11 of 16, 69%; small = 12 of 36, 33%; no cribriform = 25 of 81, 31%; χ2 P-value 0.01). On multivariate analysis, large cribriform glands were also associated with adverse pathology, independent of age, prostate-specific antigen (PSA)/PSA density at diagnosis, year of diagnosis and biopsy cores percentage positive (global P-value 0.02). Large cribriform glands were also associated with increased CAPRA-S surgical risk score (Kruskal-Wallis P-value 0.02).

CONCLUSIONS

Large cribriform glands using a diameter > 0.25 mm definition in Grade Group 2 patients on biopsy are associated with increased risk of adverse pathology at radical prostatectomy. The presence of large cribriform histology should be considered when offering active surveillance for those with Grade Group 2 disease.

Addition of cribriform pattern 4 and intraductal prostatic carcinoma into the CAPRA-S tool improves post-radical prostatectomy patient stratification in a multi-institutional cohort

AIMS

Pre-surgical risk classification tools for prostate cancer have shown better patient stratification with the addition of cribriform pattern 4 (CC) and intraductal prostatic carcinoma (IDC) identified in biopsies. Here, we analyse the additional prognostic impact of CC/IDC observed in prostatectomies using Cancer of Prostate Risk Assessment post-surgical (CAPRA-S) stratification.

METHODS

A retrospective cohort of treatment-naïve radical prostatectomy specimens from three North American academic institutions (2010-2018) was assessed for the presence of CC/IDC. Patients were classified, after calculating the CAPRA-S scores, into low-risk (0-2), intermediate-risk (3-5) and high-risk (6-12) groups. Kaplan-Meier curves were created to estimate biochemical recurrence (BCR)-free survival. Prognostic performance was examined using Harrell's concordance index, and the effects of CC/IDC within each risk group were evaluated using the Cox proportional hazards models.

RESULTS

Our cohort included 825 prostatectomies (grade group (GG)1, n=94; GG2, n=475; GG3, n=185; GG4, n=13; GG5, n=58). CC/IDC was present in 341 (41%) prostatectomies. With a median follow-up of 4.2 years (range 2.9-6.4), 166 (20%) patients experienced BCR. The CAPRA-S low-risk, intermediate-risk and high-risk groups comprised 357 (43%), 328 (40%) and 140 (17%) patients, and discriminated for BCR-free survival (p<0.0001). For CAPRA-S scores 3-5, the addition of CC/IDC status improved stratification for BCR (HR 2.27, 95% CI 1.41 to 3.66, p<0.001) and improved the overall c-index (0.689 vs 0.667, analysis of variance p<0.001).

CONCLUSION

The addition of CC/IDC into the CAPRA-S classification significantly improved post-radical prostatectomy patient stratification for BCR among the intermediate-risk group (CAPRA-S scores 3-5). The reporting of CC and IDC should be included in future prostate cancer stratification tools for improved outcome prediction.

Active surveillance should be considered for select men with Grade Group 2 prostate cancer

BACKGROUND

Treatment decisions for localized prostate cancer must balance patient preferences, oncologic risk, and preservation of sexual, urinary and bowel function. While Active Surveillance (AS) is the recommended option for men with Grade Group 1 (Gleason Score 3 + 3 = 6) prostate cancer without other intermediate-risk features, men with Grade Group 2 (Gleason Score 3 + 4 = 7) are typically recommended active treatment. For select patients, AS can be a possible initial management strategy for men with Grade Group 2. Herein, we review current urology guidelines and the urologic literature regarding recommendations and evidence for AS for this patient group.

MAIN BODY

AS benefits men with prostate cancer by maintaining their current quality of life and avoiding treatment side effects. AS protocols with close follow up always allow for an option to change course and pursue curative treatment. All the major guideline organizations now include Grade Group 2 disease with slightly differing definitions of eligibility based on risk using prostate-specific antigen (PSA) level, Gleason score, clinical stage, and other factors. Selected men with Grade Group 2 on AS have similar rates of deferred treatment and metastasis to men with Grade Group 1 on AS. There is a growing body of evidence from randomized controlled trials, large observational (prospective and retrospective) cohorts that confirm the oncologic safety of AS for these men. While some men will inevitably conclude AS at some point due to clinical reclassification with biopsy or imaging, some men may be able to stay on AS until transition to watchful waiting (WW). Magnetic resonance imaging is an important tool to confirm AS eligibility, to monitor progression and guide prostate biopsy.

CONCLUSION

AS is a viable initial management option for well-informed and select men with Grade Group 2 prostate cancer, low volume of pattern 4, and no other adverse clinicopathologic findings following a well-defined monitoring protocol. In the modern era of AS, urologists have tools at their disposal to better stage patients at initial diagnosis, risk stratify patients, and gain information on the biologic potential of a patient's prostate cancer.

In-Depth Comparison of Genetic Variants Demonstrates a Close Relationship Between Invasive and Intraductal Components of Prostate Cancer

Intraductal carcinoma (IDC) of the prostate is often associated with concurrent high-grade invasive prostate cancer (PCa) and poor clinical outcomes. In this context, IDC is thought to represent the retrograde spread of invasive prostatic adenocarcinoma into the acini and ducts. Prior studies have demonstrated a concordance of PTEN loss and genomic instability between the IDC and high-grade invasive components of PCa, but larger genomic association studies to solidify our understanding of the relationship between these 2 lesions are lacking. Here, we evaluate the genomic relationship between duct-confined (high-grade prostatic intraepithelial neoplasia and IDC) and invasive components of high-grade PCa using genetic variants generated by whole exome sequencing. High-grade prostatic intraepithelial neoplasia and IDC were laser-microdissected, and PCa and nonneoplastic tissue was manually dissected from 12 radical prostatectomies. A targeted next-generation sequencing panel was used to identify disease-relevant variants. Additionally, the degree of overlap between adjacent lesions was determined by comparing exome-wide variants detected using whole exome sequencing data. Our results demonstrate that IDC and invasive high-grade PCa components show common genetic variants and copy number alterations. Hierarchical clustering of genome-wide variants suggests that in these tumors, IDC is more closely related to the high-grade invasive components of the tumor compared with high-grade prostatic intraepithelial neoplasia. In conclusion, this study reinforces the concept that, in the context of high-grade PCa, IDC likely represents a late event associated with tumor progression.

Impact of Epithelial Histological Types, Subtypes, and Growth Patterns on Oncological Outcomes for Patients with Nonmetastatic Prostate Cancer Treated with Curative Intent: A Systematic Review

CONTEXT

The optimal management for men with prostate cancer (PCa) with unconventional histology (UH) is unknown. The outcome for these cancers might be worse than for conventional PCa and so different approaches may be needed.

OBJECTIVE

To compare oncological outcomes for conventional and UH PCa in men with localized disease treated with curative intent.

EVIDENCE ACQUISITION

A systematic review adhering to the Referred Reporting Items for Systematic Reviews and Meta-Analyses was prospectively registered on PROSPERO (CRD42022296013) was performed in July 2021.

EVIDENCE SYNTHESIS

We screened 3651 manuscripts and identified 46 eligible studies (reporting on 1 871 814 men with conventional PCa and 6929 men with 10 different PCa UHs). Extraprostatic extension and lymph node metastases, but not positive margin rates, were more common with UH PCa than with conventional tumors. PCa cases with cribriform pattern, intraductal carcinoma, or ductal adenocarcinoma had higher rates of biochemical recurrence and metastases after radical prostatectomy than for conventional PCa cases. Lower cancer-specific survival rates were observed for mixed cribriform/intraductal and cribriform PCa. By contrast, pathological findings and oncological outcomes for mucinous and prostatic intraepithelial neoplasia (PIN)-like PCa were similar to those for conventional PCa. Limitations of this review include low-quality studies, a risk of reporting bias, and a scarcity of studies that included radiotherapy.

CONCLUSIONS

Intraductal, cribriform, and ductal UHs may have worse oncological outcomes than for conventional and mucinous or PIN-like PCa. Alternative treatment approaches need to be evaluated in men with these cancers.

PATIENT SUMMARY

We reviewed the literature to explore whether prostate cancers with unconventional growth patterns behave differently to conventional prostate cancers. We found that some unconventional growth patterns have worse outcomes, so we need to investigate if they need different treatments. Urologists should be aware of these growth patterns and their clinical impact.

Cribriform morphology is associated with higher risk of biochemical recurrence after radical prostatectomy in patients with Grade Group 5 prostate cancer

AIMS

Grade Group 5 (GG5) prostate cancer (PCa) is associated with a high risk of disease recurrence after radical prostatectomy (~75% at 5 years). However, this is a heterogeneous category that includes neoplasms with different combinations of Gleason pattern (GP) 4 and 5. Within GP4, large cribriform growth has been associated with adverse disease-specific outcomes in GG2-4 PCa. Less is known about the significance of cribriform morphology and the different histologic patterns of GP5 in GG5 PCa.

METHODS AND RESULTS

In this study we evaluated the prognostic implications of cribriform morphology (either invasive or intraductal, henceforth "cribriform") and large solid growth or comedonecrosis (comedo/solid) in patients with GG5 PCa. One-hundred and thirty prostatectomies from a single institution were analysed. The presence of comedo/solid components was associated with a higher frequency of concurrent cribriform PCa (85.7% versus 45.9%, P < 0.001), lymphovascular invasion (44.6% versus 27%, P = 0.04), and biochemical recurrence (48.2% versus 28.4%, P = 0.03). The presence of large cribriform growth was associated with a higher frequency of extraprostatic involvement (i.e. pT3a-b; 85.3% versus 68.7%, P = 0.02), positive surgical margins (47.6% versus 29.2%, P = 0.04) and biochemical recurrence (47.6% versus. 18.7%, P = 0.001). Kaplan-Meier analysis demonstrated that GG5 PCa with cribriform or comedo/solid components had a higher probability of biochemical recurrence. Multivariable analysis showed that only cribriform components were an independent predictor of a higher risk of biochemical recurrence in this series.

CONCLUSION

These findings highlight the importance of reporting the presence of cribriform components in GG5 PCa and suggest that cribriform morphology might help decide postsurgical management in these patients.

Impact of cribriform pattern 4 and intraductal prostatic carcinoma on National Comprehensive Cancer Network (NCCN) and Cancer of Prostate Risk Assessment (CAPRA) patient stratification

Pretreatment classification tools are used in prostate cancer to inform patient management. The effect of cribriform pattern 4 (CC) and intraductal carcinoma (IDC) on such nomograms is still underexplored. We analyzed the Cancer of Prostate Risk Assessment (CAPRA) and National Comprehensive Cancer Network (NCCN) risk scores in cases with and without CC/IDC to assess impact on biochemical recurrence (BCR) and metastases/death of prostate cancer (event free survival-EFS) after prostatectomy. A matched biopsy- prostatectomy cohort (2010-2017) was reviewed for CC/IDC. CAPRA and NCCN scores were calculated. CAPRA score 0-2 were deemed "low", 3-5 "intermediate" and 6-10 "high". NCCN scores 1-2 "very low/low", 3 "favorable intermediate", 4 "unfavorable intermediate", 5-6 "high/very high". Cases were stratified by presence of CC/IDC. BCR and EFS probabilities were estimated using the Kaplan-Meier method. Prognostic performance was evaluated using log-rank tests and Harrell's concordance index. 612 patients with mean age 63.1 years were included with mean follow up of 5.3 (range 0-10.8) years. CC/IDC was noted in 159/612 (26%) biopsies. There were 101 (17%) BCR and 36 (6%) events. CAPRA discriminated three distinct risk categories for BCR (p < 0.001) while only high risk separated significantly for EFS (p < 0.001). NCCN distinguished two prognostic groups for BCR (p < 0.0001) and three for EFS (p < 0.0001). Addition of CC/IDC to CAPRA impacted scores 3-5 for BCR and scores 3-5 and 6-10 for EFS and improved the overall concordance index (BCR: 0.66 vs. 0.71; EFS: 0.74 vs. 0.80). Addition of CC/IDC to NCCN impacted scores 4 and 5-6 and also improved the concordance index for BCR (0.62 vs. 0.68). Regarding EFS, NCCN scores 4 and 5-6 demonstrated markedly different outcomes with the addition of CC/IDC. The CAPRA nomogram allows better outcome stratification than NCCN. Addition of CC/IDC status particularly improves patient stratification for CAPRA scores 3-5, 6-10, and for NCCN scores 4 and 5-6.

Transcriptomic Features of Cribriform and Intraductal Carcinoma of the Prostate

BACKGROUND

Cribriform (CF) and/or intraductal carcinoma (IDC) are associated with more aggressive prostate cancer (CaP) and worse outcomes.

OBJECTIVE

The transcriptomic features that typify CF/IDC are not well described and the capacity for clinically utilized genomic classifiers to improve risk modeling for CF/IDC remains undefined.

DESIGN, SETTING, AND PARTICIPANTS

We performed a retrospective review of CaP patients who had Decipher testing at a single high-volume institution. Index lesions from radical prostatectomy specimens were identified by genitourinary pathologists who simultaneously reviewed prostatectomy specimens for the presence of CF and IDC features. Patients were grouped based on pathologic features, specifically the absence of CF/IDC (CF-/IDC-), CF positive only (CF+/IDC-), and CF/IDC positive (CF+/IDC+).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical, pathologic, and genomic categorical variables were assessed using the Pearson chi-square test, while quantitative variables were assessed with the Kruskal-Wallis test. Multivariable logistic regression was used to identify the predictors of high-risk Decipher scores (>0.60). A gene set enrichment analysis was performed to identify genes and gene networks associated with CF/IDC status.

RESULTS AND LIMITATIONS

A total of 463 patients were included. Patients who were CF+/IDC+ had the highest Decipher risk scores (CF+/IDC+: 0.79 vs CF+/IDC-: 0.71 vs CF-/IDC-: 0.56, p < 0.001). On multivariate logistic regression, predictors of high-risk Decipher scores included the presence of CF, both alone (CF+/IDC-; odds ratio [OR]: 5.45, p < 0.001) or in combination with positive IDC status (CF+/IDC+; OR: 6.87, p < 0.001). On the gene set enrichment analysis, MYC pathway upregulation was significantly enriched in tumor samples from CF/IDC-positive patients (normalized enrichment score [NES]: 1.65, p = 0.046). Other enriched pathways included E2F targets (NES: 1.69, p = 0.031) and oxidative phosphorylation (NES: 1.68, =0 .033).

CONCLUSIONS

This is the largest series identifying an association between a clinically validated genomic classifier and the presence of CF and IDC at radical prostatectomy. Tumors with CF and intraductal features were associated with aggressive transcriptomic signatures.

PATIENT SUMMARY

Genomic-based tests are becoming readily available for the management of prostate cancer. We observed that Decipher, a commonly used genomic test in prostate cancer, correlates with unfavorable features in tissue specimens.

The highest percentage of Gleason Pattern 4 is a predictor in intermediate-risk prostate cancer

Objectives

This study aims to clarify the clinicopathological significance of several novel pathological markers, including the percentage of Gleason pattern 4 and small/non-small cribriform pattern, in intermediate-risk Gleason score 3 + 4 = 7 prostate cancer.

Subjects and Methods

Two-hundred and twenty-eight patients with Gleason score 3 + 4 = 7 intermediate-risk prostate cancer who underwent radical prostatectomy between 2009 and 2019 at our institute were selected. Preoperative clinicopathological characteristics, including serum prostate-specific antigen level, clinical T stage, percentage of cancer-positive cores at biopsy, small/non-small cribriform pattern, the highest percentage of Gleason pattern 4, the total length of Gleason pattern 4 and percentage of Gleason score 7 cores were examined in univariate/multivariate logistic regression analysis to determine their predictive value for postoperative adverse pathological findings, defined as an upgrade to Gleason score 4 + 3 = 7 or higher, pN1 or pT3b disease.

Results

Fifty-four cases (23.7%) showed adverse pathological findings. Although a non-small cribriform pattern, highest Gleason pattern 4 percentage and total length of Gleason pattern 4 were predictive of adverse pathological findings in univariate analysis, only the highest Gleason pattern 4 percentage was an independent predictive factor in multivariate analysis (odds ratio: 1.610; 95% confidence interval: 1.260-2.070; P = 0.0002).

Conclusion

The highest Gleason pattern 4 percentage was a potent predictive parameter for Gleason score 3 + 4 = 7 intermediate-risk prostate cancer and should be considered in the risk classification scheme for prostate cancer.

WHO Classification of Tumours fifth edition: evolving issues in the classification, diagnosis, and prognostication of prostate cancer

The fifth edition of the WHO Classification of Tumours of the Urinary and Male Genital Systems encompasses several updates to the classification and diagnosis of prostatic carcinoma as well as incorporating advancements in the assessment of its prognosis, including recent grading modifications. Some of the salient aspects include: (1) recognition that prostatic intraepithelial neoplasia (PIN)-like carcinoma is not synonymous with a pattern of ductal carcinoma, but better classified as a subtype of acinar adenocarcinoma; (2) a specific section on treatment-related neuroendocrine prostatic carcinoma in view of the tight correlation between androgen deprivation therapy and the development of prostatic carcinoma with neuroendocrine morphology, and the emerging data on lineage plasticity; (3) a terminology change of basal cell carcinoma to "adenoid cystic (basal cell) cell carcinoma" given the presence of an underlying MYB::NFIB gene fusion in many cases; (4) discussion of the current issues in the grading of acinar adenocarcinoma and the prognostic significance of cribriform growth patterns; and (5) more detailed coverage of intraductal carcinoma of prostate (IDC-P) reflecting our increased knowledge of this entity, while recommending the descriptive term atypical intraductal proliferation (AIP) for lesions falling short of IDC-P but containing more atypia than typically seen in high-grade prostatic intraepithelial neoplasia (HGPIN). Lesions previously regarded as cribriform patterns of HGPIN are now included in the AIP category. This review discusses these developments, summarising the existing literature, as well as the emerging morphological and molecular data that underpins the classification and prognostication of prostatic carcinoma.

Predictive value of Cribriform and Intraductal Carcinoma for the Nomogram-Based Selection of Prostate Cancer Patients for Pelvic Lymph Node Dissection

OBJECTIVE

To assess the predictive value of biopsy-identified cribriform carcinoma and/or intraductal carcinoma (CR/IDC) within the Briganti and MSKCC nomograms predicting lymph node metastasis (LNM) in patients with primary prostate cancer (PCa).

METHODS

We retrospectively included 393 PCa patients who underwent radical prostatectomy with extended pelvic lymph node dissection at three tertiary referral centers. We externally validated two prediction tools: the Briganti 2012 nomogram and the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram. Both nomograms were augmented with CR/IDC. The original model was compared with the CR/IDC-updated model using the likelihood ratio test. The performance of the prediction tools was assessed using calibration, discrimination, and clinical utility.

RESULTS

Overall, 109 (28%) men were diagnosed with LNM. Calibration plots of the Briganti and MSKCC nomograms demonstrated an underestimation of the LNM risk across clinically relevant thresholds (≤15%). The addition of CR/IDC to the Briganti nomogram increased the fit of the data (χ²(1)=4.30, p=0.04), but did not improve the area under the curve (AUC) (0.69, 95% CI 0.63-0.75 vs. 0.69, 95% CI 0.64-0.75). Incorporation of CR/IDC in the MSKCC nomogram resulted in an increased fit on the data (χ²(1)=10.04, p<0.01), but did not increase the AUC (0.66, 95% CI 0.60-0.72 vs 0.68, 95% CI 0.62-0.74). The addition of CR/IDC to the Briganti and MSKCC nomograms did not improve the clinical risk prediction.

CONCLUSIONS

Incorporation of CR/IDC into the two clinically most used pre-radical prostatectomy nomograms does not improve LNM prediction in a multinational, contemporary PCa cohort.

Alternative prostate cancer grading systems incorporating percent pattern 4/5 (IQ-Gleason) and cribriform architecture (cGrade) improve prediction of outcome after radical prostatectomy

Percentage Gleason pattern 4, invasive cribriform and/or intraductal carcinoma (IC/IDC) and minor pattern 5 are recognized as independent parameters for prostate cancer outcome, but are not incorporated in current grade groups (GGs). Two proof-of-principle studies have proposed alternative grading schemes based on percentage Gleason pattern 4/5 (integrated quantitative Gleason score; IQ-Gleason) and IC/IDC presence (cribriform grade; cGrade). Our objective was to compare the performance of GG, IQ-Gleason and cGrade for predicting biochemical recurrence and metastasis after radical prostatectomy (RP). RP specimens of 1064 patients were pathologically reviewed and graded according to the three schemes. Discriminative power for prediction of biochemical recurrence-free (BCRFS) and metastasis-free (MFS) survival was compared using Harrell's c-index. The GG distribution at RP was 207 (19.4%) GG1, 472 (44.4%) GG2, 126 (11.8%) GG3, 140 (13.2%) GG4 and 119 (11.2%) GG5. Grading according to 5-tier IQ-Gleason and cGrade systems led to categorical shifts in 49.8% and 29.7% of cases, respectively. Continuous IQ-Gleason had the best performance for predicting BCRFS (c-index 0.743, 95% confidence interval (CI) 0.715-0.771), followed by cGrade (c-index 0.738, 95%CI 0.712-0.759), 5-tier categorical IQ-Gleason (c-index 0.723, 95%CI 0.695-0.750) and GG (c-index 0.718, 95%CI 0.691-0.744). Continuous IQ-Gleason (c-index 0.834, 95%CI 0.802-0.863) and cGrade (c-index 0.834, 95%CI 0.808-0.866) both had better predictive value for MFS than categorical IQ-Gleason (c-index 0.823, 95%CI 0.788-0.857) and GG (c-index 0.806, 95%CI 0.777-0.839). In conclusion, the performance of prostate cancer grading can be improved by alternative grading schemes incorporating percent Gleason pattern 4/5 and IC/IDC.

AI Model for Prostate Biopsies Predicts Cancer Survival

An artificial intelligence (AI) algorithm for prostate cancer detection and grading was developed for clinical diagnostics on biopsies. The study cohort included 4221 scanned slides from 872 biopsy sessions at the HUS Helsinki University Hospital during 2016–2017 and a subcohort of 126 patients treated by robot-assisted radical prostatectomy (RALP) during 2016–2019. In the validation cohort (n = 391), the model detected cancer with a sensitivity of 98% and specificity of 98% (weighted kappa 0.96 compared with the pathologist’s diagnosis). Algorithm-based detection of the grade area recapitulated the pathologist’s grade group. The area of AI-detected cancer was associated with extra-prostatic extension (G5 OR: 48.52; 95% CI 1.11–8.33), seminal vesicle invasion (cribriform G4 OR: 2.46; 95% CI 0.15–1.7; G5 OR: 5.58; 95% CI 0.45–3.42), and lymph node involvement (cribriform G4 OR: 2.66; 95% CI 0.2–1.8; G5 OR: 4.09; 95% CI 0.22–3). Algorithm-detected grade group 3–5 prostate cancer depicted increased risk for biochemical recurrence compared with grade groups 1–2 (HR: 5.91; 95% CI 1.96–17.83). This study showed that a deep learning model not only can find and grade prostate cancer on biopsies comparably with pathologists but also can predict adverse staging and probability for recurrence after surgical treatment.

Prevalence of adverse pathology features in grade group 2 prostatectomy specimens with syn- or metachronous metastatic disease

BACKGROUND

To validate the importance of recently established adverse histopathology features (cribriform pattern and intraductal carcinoma) as contra-indication for deferred treatment of Gleason score 7 (3 + 4) (grade group [GG] 2) prostate cancer, we investigated their frequency in GG2 radical prostatectomies with syn- or metachronous metastatic disease.

METHODS

GG2 prostatectomy specimens of patients with concomitant lymph node metastasis or distant metastasis at follow-up were identified in a clinical database of a tertiary care center and their pathology was reviewed for pathological stage, lymphovascular invasion, Gleason grade 4 subpatterns, presence of tertiary grade 5, and ductal adenocarcinoma histology. A control group of 99 GG2 prostatectomy specimens who had no metastatic disease (controls) was reviewed for the same adverse pathological features.

RESULTS

Of 1860 GG2 prostatectomy specimens (operated between 2002 and 2020), 45 (2.4%) had concurrent regional lymph node metastases or distant metastases at follow-up. Pathological stage distribution of cases and controls was 24% and 79% pT2, 42% and 15% pT3a, 33% and 6.1% pT3b -T4, respectively (p < 0.001). Eleven of 45 cases (24%) had ≤10% Gleason grade 4 component. Cribriform pattern or intraductal carcinoma was present in 84% of cases versus 34% of controls (p < 0.001), tertiary grade 5 in 16% of cases versus 5% controls (p = 0.05) and ductal adenocarcinoma in 16% of cases versus 2% of controls (p = 0.004). Among the seven cases without cribriform or intraductal carcinoma, two displayed ductal adenocarcinoma features.

CONCLUSIONS

Well-established unfavorable histopathologic features (intraductal and cribriform pattern carcinoma, ductal adenocarcinoma) are represented in about 90% of GG2 prostate cancers with local or distant metastatic disease and are much less common (38%) in those without metastatic disease. Strikingly, about 25% of GG2 prostatectomy cases with metastatic disease had an organ-confined disease and/or a small percentage of Gleason grade 4 pattern. This further emphasizes the relative importance of these adverse histopathological features (cribriform, intraductal, and ductal adenocarcinoma) rather than percentage Gleason grade 4 as contra-indicator of deferred treatment for patients with GG2 prostate cancer.

Percentage Gleason pattern 4 and PI-RADS score predict upgrading in biopsy Grade Group 2 prostate cancer patients without cribriform pattern

PURPOSE

To identify parameters to predict upgrading in biopsy Grade Group (GG) 2 prostate cancer patients without cribriform and intraductal carcinoma (CR/IDC) on biopsy.

METHODS

Preoperative biopsies from 657 men undergoing radical prostatectomy (RP) for prostate cancer were reviewed for GG, presence of CR/IDC, percentage Gleason pattern 4, and tumor length. In men with biopsy GG2 without CR/IDC (n = 196), clinicopathologic features were compared between those with GG1 or GG2 without CR/IDC on RP (GG ≤ 2-) and those with GG2 with CR/IDC or any GG > 2 (GG ≥ 2+). Logistic regression analysis was used to predict upgrading in the biopsy cohort.

RESULTS

In total 283 men had biopsy GG2 of whom 87 (30.7%) had CR/IDC and 196 (69.3%) did not. CR/IDC status in matched biopsy and RP specimens was concordant in 179 (63.3%) and discordant in 79 (27.9%) cases (sensitivity 45.1%; specificity 92.6%). Of 196 biopsy GG2 men without CR/IDC, 106 (54.1%) had GG ≥ 2+ on RP. Multivariable logistic regression analysis showed that age [odds ratio (OR): 1.85, 95% confidence interval (CI)1.09-3.20; p = 0.025], percentage Gleason pattern 4 (OR 1.54, 95% CI 1.17-2.07; p = 0.003), PI-RADS 5 lesion (OR 2.17, 95% CI 1.03-4.70; p = 0.045) and clinical stage T3 (OR 3.60; 95% CI 1.08-14.50; p = 0.049) were independent parameters to predict upgrading to GG ≥  2+ on RP in these men.

CONCLUSIONS

Age, clinical stage T3, percentage Gleason pattern 4 and presence of PI-RADS 5 lesions are independent predictors for upgrading in men with biopsy GG2 without CR/IDC. These findings allow for improved clinical decision-making on surveillance eligibility in intermediate-risk prostate cancer patients.

Prognostic Utility of the Gleason Grading System Revisions and Histopathological Factors Beyond Gleason Grade

Background

The International Society of Urological Pathology (ISUP) revised the Gleason system in 2005 and 2014. The impact of these changes on prostate cancer (PCa) prognostication remains unclear.

Objective

To evaluate if the ISUP 2014 Gleason score (GS) predicts PCa death better than the pre-2005 GS, and if additional histopathological information can further improve PCa death prediction.

Patients and Methods

We conducted a case–control study nested among men in the National Prostate Cancer Register of Sweden diagnosed with non-metastatic PCa 1998–2015. We included 369 men who died from PCa (cases) and 369 men who did not (controls). Two uro-pathologists centrally re-reviewed biopsy ISUP 2014 Gleason grading, poorly formed glands, cribriform pattern, comedonecrosis, perineural invasion, intraductal, ductal and mucinous carcinoma, percentage Gleason 4, inflammation, high-grade prostatic intraepithelial neoplasia (HGPIN) and post-atrophic hyperplasia. Pre-2005 GS was back-transformed using i) information on cribriform pattern and/or poorly formed glands and ii) the diagnostic GS from the registry. Models were developed using Firth logistic regression and compared in terms of discrimination (AUC).

Results

The ISUP 2014 GS (AUC = 0.808) performed better than the pre-2005 GS when back-transformed using only cribriform pattern (AUC = 0.785) or both cribriform and poorly formed glands (AUC = 0.792), but not when back-transformed using only poorly formed glands (AUC = 0.800). Similarly, the ISUP 2014 GS performed better than the diagnostic GS (AUC = 0.808 vs 0.781). Comedonecrosis (AUC = 0.811), HGPIN (AUC = 0.810) and number of cores with ≥50% cancer (AUC = 0.810) predicted PCa death independently of the ISUP 2014 GS.

Conclusion

The Gleason Grading revisions have improved PCa death prediction, likely due to classifying cribriform patterns, rather than poorly formed glands, as Gleason 4. Comedonecrosis, HGPIN and number of cores with ≥50% cancer further improve PCa death discrimination slightly.

PTEN expression and morphological patterns in prostatic adenocarcinoma

AIMS

Cribriform morphology, which includes intraductal carcinoma (IDCP) and invasive cribriform carcinoma, is an indicator of poor prognosis in prostate cancer. Phosphatase and tensin homologue (PTEN) loss is a predictor of adverse clinical outcomes. The association between PTEN expression and morphological patterns of prostate cancer is unclear.

METHODS AND RESULTS

We explored the association between PTEN expression by immunohistochemistry, Gleason pattern 4 morphologies, IDCP and biochemical recurrence (BCR) in 163 radical prostatectomy specimens. IDCP was delineated from invasive cribriform carcinoma by p63 positive immunohistochemical staining in basal cells. Combined invasive cribriform carcinoma and IDCP were associated with a higher cumulative incidence of BCR [hazard ratio (HR) = 5.06; 2.21, 11.6, P < 0.001]. When including PTEN loss in the analysis, invasive cribriform carcinoma remained predictive of BCR (HR = 3.72; 1.75, 7.94, P = 0.001), while PTEN loss within invasive cribriform carcinoma did not. Glomeruloid morphology was associated with lower odds of cancer stage pT3 and lower cumulative incidence of BCR (HR = 0.27; 0.088, 0.796, P = 0.018), while PTEN loss within glomeruloid morphology was associated with a higher cumulative incidence of BCR (HR = 4.07; 1.04, 15.9, P = 0.043).

CONCLUSIONS

PTEN loss within glomeruloid pattern was associated with BCR. The presence of any cribriform pattern was associated with BCR, despite PTEN loss not significantly associated with invasive cribriform carcinoma. We speculate that other drivers independent from PTEN loss may contribute to poor prognostic features in cribriform carcinoma.

Cribriform glands are associated with worse outcome than other pattern 4 subtypes: A study of prognostic and clinicopathological characteristics of prostate adenocarcinoma with an emphasis on Grade Groups

AIM

Although prostate adenocarcinoma is the most common cancer in men, survival is quite high and with the help of histopathological examination using the updated classification, patient management strategies are developing. We aimed to evaluate the correlation between the histopathological features and biochemical recurrence (BCR) in patients who underwent radical prostatectomy (RP) using the new classification.

METHODS

A total of 285 prostate adenocarcinoma cases that underwent RP between January 2009 and December 2017 and followed up for at least 3 months were included in the study. The cases were re-evaluated according to WHO-ISUP 2016 classification and the findings were recorded.

RESULTS

The mean age was 63,4 years. Gleason scores of the cases were as follows: 3+3 144 cases (50.5%), 3+4 81 cases (28.4%), 4+3 28 cases (9.8%), 4+4 7 cases (2.5%) , 3+5 6 cases (2.1%), 5+3 2 cases (0.7%), 4+5 17 cases (6%). There were 198 (69,5%) pT2, 54 (18,9%) pT3a and 33 (11,6%) pT3b cases. The mean follow-up time was 44,1 months and BCR was detected in 97 cases (34%). The relationship between the Group Grades and BCR was statistically significant. BCR rate increased as the tumour volume and the percentage of pattern 4 increased (P < .001).There was a significant correlation between preoperative PSA value, extraprostatic extension, seminal vesicle invasion, surgical margin positivity, tumour volume, pattern 4 percentage, presence of cribriform glands and BCR and recurrence-free survival in both univariate and multivariate analysis and recurrence-free survival was also affected by these parameters. Among the morphological subtypes of Pattern 4, recurrence-free survival decreased as the incidence of cribriform glands increased (P < .001).

CONCLUSION

Histopathological evaluation is important in predicting BCR in prostate adenocarcinoma, the Group Grade system seems to be helpful in this regard. More studies are needed to prove the relatively worse prognostic effect of cribriform glands.

Somatic driver mutation prevalence in 1844 prostate cancers identifies ZNRF3 loss as a predictor of metastatic relapse

Driver gene mutations that are more prevalent in metastatic, castration-resistant prostate cancer (mCRPC) than localized disease represent candidate prognostic biomarkers. We analyze 1,844 localized (1,289) or mCRPC (555) tumors and quantify the prevalence of 113 somatic driver single nucleotide variants (SNVs), copy number aberrations (CNAs), and structural variants (SVs) in each state. One-third are significantly more prevalent in mCRPC than expected while a quarter are less prevalent. Mutations in AR and its enhancer are more prevalent in mCRPC, as are those in TP53, MYC, ZNRF3 and PRKDC. ZNRF3 loss is associated with decreased ZNRF3 mRNA abundance, WNT, cell cycle & PRC1/2 activity, and genomic instability. ZNRF3 loss, RNA downregulation and hypermethylation are prognostic of metastasis and overall survival, independent of clinical and pathologic indices. These data demonstrate a strategy for identifying biomarkers of localized cancer aggression, with ZNRF3 loss as a predictor of metastasis in prostate cancer.

Cribriform architecture outperforms percent Gleason pattern 4 and tertiary pattern 5 in predicting outcome of Grade group 2 prostate cancer patients

Aims

Gleason pattern 4 (GP4) percentage, invasive cribriform and/or intraductal carcinoma (IC/IDC) and the presence of tertiary Gleason pattern 5 (TP5) in radical prostatectomy (RP) specimens all aid in the risk stratification of Grade Group (GG) 2 prostate cancer patients. However, it is unclear to what extent these pathological features are mutually related and what are their individual values if they are investigated simultaneously. The aims of this study were: (i) to determine the mutual relationships of the GP4 percentage, IC/IDC and TP5 in GG2 RP specimens; and (ii) to assess their prognostic value for biochemical recurrence‐free survival (BCRFS).

Methods and results

Of 1064 RP specimens, 472 (44.4%) showed GG2 prostate cancer. Patients with ≥25% GP4 more frequently had IC/IDC (67.0% versus 43.9%; P < 0.001) and TP5 (20.6% versus 5.8%; P < 0.001) than those with <25% GP4. In unadjusted analysis, an increased GP4 percentage [hazard ratio (HR) 1.3; 95% confidence interval (CI) 1.0–1.6; P = 0.04] and IC/IDC (log rank P < 0.001) were associated with shorter BCRFS, whereas TP5 (P = 0.12) and a dichotomised (<25%, ≥25%) GP4 percentage (P = 0.10) were not. In multivariable analysis, IC/IDC was an independent prognostic factor (HR 1.9; 95% CI 1.2–2.9; P = 0.005) for BCRFS, whereas a continuous or dichotomised GP4 percentage and TP5 were not independent prognostic factors.

Conclusion

In conclusion, a higher GP4 percentage in RP specimens was associated with more frequent IC/IDC and TP5. IC/IDC was an independent predictor for BCRFS, whereas the GP4 percentage and TP5 were not. These findings underscore the importance of routinely including the presence of IC/IDC in RP pathology reports.

Subpathologies and genomic classifier for treatment individualization of post-prostatectomy radiotherapy

PURPOSE/OBJECTIVE

Risk-stratification for post-prostatectomy radiotherapy (PORT) using conventional clinicopathologic indexes leads to substantial over- and under-treatment. Better patient selection could spare unnecessary toxicities and improve outcomes. We investigated the prognostic utility of unfavorable subpathologies intraductal carcinoma and cribriform architecture (IDC/CA), and a 22-gene Decipher genomic classifier (GC) in prostate cancer (PCa) patients receiving PORT.

MATERIAL/METHODS

A cohort of 302 men who received PORT at 2 academic institutions was pooled. PORT was predominately delivered as salvage (62% of cases); 20% received HT+PORT. Specimens were centrally reviewed for IDC/CA presence. In 104 cases, GC scores were determined. Endpoints were biochemical relapse-free (bRFR) and metastasis-free (mFR) rates.

RESULTS

After a median follow-up of 6.49-years, 135 (45%) and 40 (13%) men experienced biochemical relapse and metastasis, respectively. IDC/CA were identified in 160 (53%) of cases. Men harboring IDC/CA experienced inferior bRFR (HR 2.6, 95%CI 1.8-3.2, P<0.001) and mFR (HR 3.1, 95%CI 1.5-6.4, P = 0.0014). Patients with GC scores, 22 (21%) were stratified low-, 30 (29%) intermediate-, and 52 (50%) high-risk. GC low-risk was associated with superior bRFR (HR 0.25, 95%CI 0.1-0.5, P<0.001) and mFR (HR 0.15, 95%CI 0.03-0.8, P = 0.025). On multivariable analyses, IDC/CA and GC independently predicted for bRFR, corresponding to improved discrimination (C-index = 0.737 (95%CI 0.662-0.813)).

CONCLUSIONS

IDC/CA subpathologies and GC predict for biochemical relapse and metastasis beyond conventional clinicopathologic indexes in the PORT setting. Patients harboring IDC/CA are at higher risk of relapse after maximal local therapies, thus warranting consideration for treatment intensification strategies. Conversely, for men with absence of IDC/CA and low GC scores, de-intensification strategies could be explored.

Prognostic value of cribriform size, percentage, and intraductal carcinoma in Gleason score 7 prostate cancer with cribriform Gleason pattern 4

Cribriform Gleason pattern 4 (CGP4) is an indicator of poor prognosis in Gleason Score 7 prostate cancer; however, the significance of the size and percentage of this pattern and the presence of concomitant intraductal carcinoma (IDC) in these patients is unclear. To study the significance of these parameters in radical prostatectomy specimens, 165 cases with CGP4 were identified and reviewed (2017-2019). The size and percentage cribriform pattern and presence of IDC were noted and correlated with adverse pathological features and biochemical recurrence (BCR)-free survival. On review, 156 cases had CGP4 (Grade Group 2: 87 and Grade Group 3: 69). Large cribriform pattern and cribriform percentage of >20% showed significant association with extraprostatic extension, surgical margin positivity, and presence of IDC, whereas the presence of IDC was associated with all the analyzed adverse pathological features. BCR was seen in 22 of 111 (20%) patients after a median follow-up of 11 months, and of these, 21 had large cribriform pattern. On univariate analysis, all parameters had significant predictive values for BCR-free survival except for tertiary Gleason pattern 5. On multivariate analysis, while >20% cribriform pattern was trending to be an independent predictor, only lymphovascular invasion was statistically significant. Large cribriform pattern, >20% cribriform, and presence of IDC are additional pathologic parameters of potential value in identifying patients with high risk for early BCR.

Active surveillance for prostate cancer

Many men diagnosed with localized prostate cancer can postpone definitive treatment without raising their risk of metastasis or death from disease. Active surveillance (AS) is a method of monitoring select men, with the option of switching to active treatment upon signs of progression, thereby avoiding the well-known side-effects of surgery and radiotherapy. This review analyzes the data from long-running AS cohorts to determine the safety and efficacy of AS. We conducted a narrative review of recently published data, including 14 articles from 13 AS cohorts. The cohorts used varying inclusion criteria, with reported differences in clinical T stage and Gleason Score (Grade Group), among other features. Some studies (n=5) limited their cohorts to low-risk patients, while others (n=8) also included intermediate-risk patients. The heterogeneity of the cohorts produced mixed results, with the risk of prostate cancer metastasis ranging from 0.1–1.0% at 10 years and the risk of prostate cancer mortality ranging from 0–1.9% at 10 years. However, the majority of studies reported risks of less than 0.5% at 10 years for both metastasis and death. For most cohorts, half of men remained untreated for 5–10 years, with estimates ranging from 37% receiving active treatment in the Toronto cohort to 73% in the Prostate Cancer Research International AS (PRIAS) study. Current data do not support the use of negative magnetic resonance imaging (MRI) to avoid scheduled biopsy. Taken together, the data collected from these AS cohorts suggests that AS is a safe approach for men with low-grade prostate cancer and some men with intermediate risk disease. AS should be more broadly implemented for eligible patients to avoid the decreases in quality of life from undergoing active treatment. Studies expanding the inclusion criteria and further defining a subset of men with favorable intermediate-risk prostate cancer who might safely benefit from AS are needed to assess the long-term outcomes of using AS in intermediate-risk groups.

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer

CONTEXT.—

Controversies and uncertainty persist in prostate cancer grading.

OBJECTIVE.—

To update grading recommendations.

DATA SOURCES.—

Critical review of the literature along with pathology and clinician surveys.

CONCLUSIONS.—

Percent Gleason pattern 4 (%GP4) is as follows: (1) report %GP4 in needle biopsy with Grade Groups (GrGp) 2 and 3, and in needle biopsy on other parts (jars) of lower grade in cases with at least 1 part showing Gleason score (GS) 4 + 4 = 8; and (2) report %GP4: less than 5% or less than 10% and 10% increments thereafter. Tertiary grade patterns are as follows: (1) replace "tertiary grade pattern" in radical prostatectomy (RP) with "minor tertiary pattern 5 (TP5)," and only use in RP with GrGp 2 or 3 with less than 5% Gleason pattern 5; and (2) minor TP5 is noted along with the GS, with the GrGp based on the GS. Global score and magnetic resonance imaging (MRI)-targeted biopsies are as follows: (1) when multiple undesignated cores are taken from a single MRI-targeted lesion, an overall grade for that lesion is given as if all the involved cores were one long core; and (2) if providing a global score, when different scores are found in the standard and the MRI-targeted biopsy, give a single global score (factoring both the systematic standard and the MRI-targeted positive cores). Grade Groups are as follows: (1) Grade Groups (GrGp) is the terminology adopted by major world organizations; and (2) retain GS 3 + 5 = 8 in GrGp 4. Cribriform carcinoma is as follows: (1) report the presence or absence of cribriform glands in biopsy and RP with Gleason pattern 4 carcinoma. Intraductal carcinoma (IDC-P) is as follows: (1) report IDC-P in biopsy and RP; (2) use criteria based on dense cribriform glands (>50% of the gland is composed of epithelium relative to luminal spaces) and/or solid nests and/or marked pleomorphism/necrosis; (3) it is not necessary to perform basal cell immunostains on biopsy and RP to identify IDC-P if the results would not change the overall (highest) GS/GrGp part per case; (4) do not include IDC-P in determining the final GS/GrGp on biopsy and/or RP; and (5) "atypical intraductal proliferation (AIP)" is preferred for an intraductal proliferation of prostatic secretory cells which shows a greater degree of architectural complexity and/or cytological atypia than typical high-grade prostatic intraepithelial neoplasia, yet falling short of the strict diagnostic threshold for IDC-P. Molecular testing is as follows: (1) Ki67 is not ready for routine clinical use; (2) additional studies of active surveillance cohorts are needed to establish the utility of PTEN in this setting; and (3) dedicated studies of RNA-based assays in active surveillance populations are needed to substantiate the utility of these expensive tests in this setting. Artificial intelligence and novel grading schema are as follows: (1) incorporating reactive stromal grade, percent GP4, minor tertiary GP5, and cribriform/intraductal carcinoma are not ready for adoption in current practice.

Assessment of MYC/PTEN Status by Gene-Protein Assay in Grade Group 2 Prostate Biopsies

This study leveraged a gene-protein assay to assess MYC and PTEN status at prostate cancer biopsy and examined the association with adverse outcomes after surgery. MYC gain and PTEN loss were simultaneously assessed by chromogenic in situ hybridization and immunohistochemistry, respectively, using 277 Grade Group 2 needle biopsies that were followed by prostatectomy. The maximal size of cribriform Gleason pattern 4 carcinoma (CRIB), the presence of intraductal carcinoma (IDC), and percentage of Gleason pattern 4 carcinoma at biopsy were also annotated. MYC gain or PTEN loss was present in 19% and 18% of biopsies, respectively, whereas both alterations were present in 9% of biopsies. Tumors with one or both alterations were significantly more likely to have non-organ-confined disease (NOCD) at radical prostatectomy. In logistic regression models, including clinical stage, tumor volume on biopsy, and presence of CRIB/IDC, cases with MYC gain and PTEN loss remained at higher risk for NOCD (odds ratio, 6.23; 95% CI, 1.74-24.55; P = 0.005). The area under the curve for a baseline model using CAPRA variables (age, prostate-specific antigen, percentage of core involvement, clinical stage) was increased from 0.68 to 0.69 with inclusion of CRIB/IDC status and to 0.75 with MYC/PTEN status. Dual MYC/PTEN status can be assessed in a single slide and is independently associated with increased risk of NOCD for Grade Group 2 biopsies.

Cribriform Prostate Cancer: Clinical Pathologic and Molecular Considerations

Intraductal cribriform (IDC) and invasive cribriform morphologies are associated with worse prostate cancer outcomes. Limited retrospective studies have associated IDC and cribriform morphology with germline mutations in DNA repair genes, particularly BRCA2. These findings, which prompted the National Comprehensive Cancer Network (NCCN) Guidelines for Prostate Cancer and Genetic/Familial High- Risk Assessment to consider germline testing for individuals with IDC/cribriform histology, have been questioned in a recent prospective study. A deepened understanding of the molecular mechanisms driving disease aggressiveness in cribriform morphology is critical to provide more clarity in clinical decision making. This review summarizes the current understanding of IDC and cribriform prostate cancer, with an emphasis on clinical outcomes and molecular alterations.

Narrative review of prostate cancer grading systems: will the Gleason scores be replaced by the Grade Groups?

The Gleason grading system, proposed by Dr. Donald F. Gleason in 1966, is one of the most important prognostic factors in men with prostate cancer (PCa). At consensus conferences held in 2005 and 2014, organized by the International Society of Urological Pathology (ISUP), the system was modified to reflect the current diagnostic and therapeutic approaches. In particular, in the 2014 Conference, it was recognized that there were weaknesses with the original and the 2005 ISUP modified Gleason systems. Based on the results of a research conducted by Prof. JI Epstein and his group, a new grading system was proposed by the ISUP in order to address some of such deficiencies: i.e., the five distinct Grade Groups (GGs). Since 2014, results of studies have been published by different groups and societies, including the Genitourinary Pathology Society (GUPS), giving additional support to the prognostic role of the architectural Gleason patterns and, in particular, of the GGs. A revised GG system, taking into account the percentage of Gleason pattern (GP) 4, cribriform and intraductal carcinoma, tertiary GP 5, and reactive stroma grade, has shown to have some advantages, however not ready for adoption in the current practice. The aim of this contribution was to review the major updates and recommendations regarding the GPs and GSs, as well as the GGs, trying to give an answer to the following questions: “How has the grade group system been used in the routine?” and “will the Gleason scoring system be replace by the grade groups?” We also discussed the potential implementation in the future of molecular pathology and artificial intelligence in grading to further define risk groups in patients with PCa.

Clinical outcome comparison of Grade Group 1 and Grade Group 2 prostate cancer with and without cribriform architecture at the time of radical prostatectomy

Aims

Invasive cribriform and intraductal carcinoma are associated with aggressive disease in Grade Group 2 (GG2) prostate cancer patients. However, the characteristics and clinical outcome of patients with GG2 prostate cancer without cribriform architecture (GG2−) as compared with those with Grade Group 1 (GG1) prostate cancer are unknown. The aim of this study was to investigate the clinical and pathological characteristics of GG1 and GG2− prostate cancer in radical prostatectomy specimens.

Methods and results

We reviewed 835 radical prostatectomy specimens for Grade Group, pT stage, surgical margin status, and the presence of cribriform architecture. Biochemical recurrence‐free survival and metastasis were used as clinical outcomes. GG1 prostate cancer was seen in 207 patients, and GG2 prostate cancer was seen in 420 patients, of whom 228 (54%) showed cribriform architecture (GG2+) and 192 (46%) did not. GG2− patients had higher prostate‐specific antigen levels (9.4 ng/ml versus 7.0 ng/ml; P < 0.001), more often had extraprostatic extension (36% versus 11%; P < 0.001) and had more positive surgical margins (27% versus 17%; P = 0.01) than GG1 patients. GG2− patients had shorter biochemical recurrence‐free survival (hazard ratio 2.7, 95% confidence interval 1.4–4.9; P = 0.002) than GG1 patients. Lymph node and distant metastasis were observed neither in GG2− nor in GG1 patients, but occurred in 22 of 228 (10%) GG2+ patients.

Conclusion

In conclusion, patients with GG2− prostate cancer at radical prostatectomy have more advanced disease and shorter biochemical recurrence‐free survival than those with GG1 prostate cancer, but both groups have a very low risk of developing metastasis.

Comparative influence of cribriform growth and percent Gleason 4 in prostatic biopsies with Gleason 3+4 cancer

The International Society of Urological Pathology endorses specifying presence of cribriform architecture in Gleason (G)4 prostate cancer because of cribriform's aggressiveness. The relative effect of cribriform presence versus percentage G4 within grade group (GG)2 or 3 was uncertain. 194 men's biopsies with GG2 with or without cribriform (excluding glomeruloid from cribriform) and GG3 without cribriform (controls) from 4 years were reviewed. 173 cases had follow-up including 147 GG2 (15/147 or 10% had cribriform) and 26 GG3. Effects of total tumor specimen involvement, %Gleason 4, and cribriform were stratified into prostatectomy (n = 90), radiotherapy (n = 61), and watching waiting (n = 22) groups. Median follow-up duration was 3.32 years (range 1.90-6.18). Biochemical failures in the above 3 cohorts numbered 9 (9/90; 10%), 5 (5/61; 8%), and 13 (13/22; 59%) respectively. In all groups, (GG2+ GG3, n = 173), the HR for C pattern was 1.64. In GG2, cribriform presence (considering glomeruloid as non-cribriform) conferred a hazard ratio (HR) of 1.51 (p = 0.48). It was 1.38, excluding glomeruloid. In watchful waiting cohort only, presence of C conferred a HR of 2.62 (p = 0.086). All remaining comparisons including percent G4, remained not significant. Thus, only in WW group did cribriform pattern presence approach significance. Detection of differences otherwise was not feasible, probably because: 1) biochemical failure is too rare in GG2 cancer; 2) cribriform frequency was only 10% in GG2 (in current study), less than in higher-grade cancer. 3) Use of biopsy tissue is subject to sampling variation which may undersample cribriform pattern, though biopsy forms the basis of treatment decisions.

Grade group 2 (10% ≥ GP4) patients have very similar malignant potential with grade group 1 patients, given the risk of intraductal carcinoma of the prostate

BACKGROUND

It has been argued that grade group 2 (GG2) with a low Gleason pattern 4 (GP4) proportion should be an indication for active surveillance (AS) of prostate cancer (PCa). However, the cut-off GP4 proportion for AS remains unclear. Here, we evaluated the effect of GP4 proportion and IDC-P on cancer recurrence following radical prostatectomy (RP) in GG1 and GG2 patients, and identified candidates for AS.

METHODS

We retrospectively evaluated 646 patients with PCa who underwent RP between 2005 and 2014, and whose specimens were of GG1 or GG2 status.

RESULTS

The GGs were as follows: GG1, 25.2% (n = 163); GG2 (5% ≥ GP4), 11.4% (n = 74); GG2 (5% < GP4 ≤ 10%), 25.9% (n = 167); and GG2 (20% ≤ GP4), 37.5% (n = 242). IDC-P was detected in 26 patients (4%), i.e., in 2/167 GG2 (5% < GP4 ≤ 10%; 1%) cases and 24/242 GG2 (20% ≤ GP4; 10%) cases. GG2 patients with IDC-P exhibited a significantly poorer prognosis than did those without IDC-P (P < 0.0001), as did GG2 (20% ≤ GP4) patients without IDC-P (P < 0.05). The GG2 (5% ≥ GP4) and (5% < GP4 ≤ 10%) groups exhibited prognoses similar to those of the GG1 patients. In multivariate analysis, GG2 (20% ≤ GP4) without IDC-P, the presence of IDC-P, and the prostate-specific antigen level at diagnosis significantly predicted prognosis (P < 0.05, < 0.0001, and < 0.0001, respectively).

CONCLUSION

Our findings suggest that GG2 (GP4 ≤ 10%) patients could be indicated for AS, similar to GG1 patients, given the risk of IDC-P tumors.

Similarities and Differences in the 2019 ISUP and GUPS Recommendations on Prostate Cancer Grading: A Guide for Practicing Pathologists

Contemporary subspecialization of practice in prostate pathology has seen a transition to complex, nuanced reporting, where a growing number of histopathologic parameters may signal differences in patient management. In this context, the International Society of Urological Pathology (ISUP) and the Genitourinary Pathology Society (GUPS) both published proceedings papers on the grading of prostate cancer in 2019. Overall, the 2 prostate cancer grading manuscripts reached many of the same conclusions and recommendations. Yet, each consensus was conducted somewhat differently, and in a couple of key areas, each reached different conclusions and recommendations. Herein, sourced from the experience and viewpoints of members of both societies, we provide the practicing pathologist a summary of the shared recommendations, and of the discordances. It is anticipated that these 2 documents will inform future iterations of recommendations and guidelines for reporting prostate cancer by organizations such as the College of American Pathologists, the Royal College of Pathologists, and the European Society of Pathology, which will promote best practices for their respective constituents. Our goal is to provide the practicing pathologist a useful catalog of the main points of both, allowing each practitioner to make informed decisions and understand any divergent opinions as may arise between observers for individual cases.

The 2019 International Society of Urological Pathology (ISUP) Consensus Conference on Grading of Prostatic Carcinoma

Five years after the last prostatic carcinoma grading consensus conference of the International Society of Urological Pathology (ISUP), accrual of new data and modification of clinical practice require an update of current pathologic grading guidelines. This manuscript summarizes the proceedings of the ISUP consensus meeting for grading of prostatic carcinoma held in September 2019, in Nice, France. Topics brought to consensus included the following: (1) approaches to reporting of Gleason patterns 4 and 5 quantities, and minor/tertiary patterns, (2) an agreement to report the presence of invasive cribriform carcinoma, (3) an agreement to incorporate intraductal carcinoma into grading, and (4) individual versus aggregate grading of systematic and multiparametric magnetic resonance imaging-targeted biopsies. Finally, developments in the field of artificial intelligence in the grading of prostatic carcinoma and future research perspectives were discussed.

Combination of total length of Gleason pattern 4 and number of Gleason score 3 + 4 = 7 cores detects similar outcome group to Gleason score 6 cancers among cases with ≥5% of Gleason pattern 4

Expanding the inclusion criteria for active prostate cancer surveillance to include cases with a Gleason score (GS) of 3 + 4 = 7 has been discussed. GS 3 + 4 = 7 cases with a percentage of Gleason pattern 4 (%GP4) <5% were shown to be associated with similar outcomes with those of GS 6 cases. We examined the clinicopathological significance of %GP4 ≥5% with a limited amount of GP4. A total of 315 radical prostatectomy cases with GS 6 or 3 + 4 = 7 in a prior biopsy, were reviewed. The cases with the highest %GP4 ≥5% were subcategorized using the total length of GP4 (GP4-TL) and number of GS 3 + 4 = 7 cores. As outcome measures, the frequency of adverse pathology (AP) and the risk of biochemical recurrence (BCR) were compared between the GS 6 and 3 + 4 = 7 subgroups. In the %GP4 ≥5% subgroup, only cases with both GP4-TL <0.5 mm and 1 core of GS 3 + 4 = 7 showed similar outcome measures with those of GS 6 cancers. However, all other subgroups showed a higher frequency of AP and/or risk of BCR than GS 6 cancers. Our results suggest that cases with %GP4 ≥5% with a limited amount of GP4 should be considered for inclusion in the active surveillance category.

Prostate cancer growth patterns beyond the Gleason score: entering a new era of comprehensive tumour grading

The Gleason grading system is one of the most important factors in clinical decision‐making for prostate cancer patients, and is entirely based on the classification of tumour growth patterns. In recent years it has become clear that some individual growth patterns themselves have independent prognostic value, and could be used for better personalised risk stratification. In this review we summarise recent literature on the clinicopathological value and molecular characteristics of individual prostate cancer growth patterns, and show how these, most particularly cribriform architecture, could alter treatment decisions for prostate cancer patients.

Intraductal carcinoma has a minimal impact on Grade Group assignment in prostate cancer biopsy and radical prostatectomy specimens

AIMS

Intraductal carcinoma (IDC) is an adverse histopathological parameter for prostate cancer outcome, but is not incorporated in current tumour grading. To account for its dismal prognosis and to omit basal cell immunohistochemistry, it has been proposed to grade IDC on the basis of its underlying architectural pattern. The aim of this study was to determine the impact of IDC grade assignment on prostate cancer biopsy and radical prostatectomy tumour grading.

METHODS AND RESULTS

A cohort of 1031 prostate cancer biopsies and 835 radical prostatectomies were assigned a Grade Group according to the 2014 International Society of Urological Pathology guidelines, without incorporation of IDC in grading. Tumour grading was compared with a Grade Group in which IDC was graded on the basis of its underlying architecture. Of 1031 biopsies, 139 (13.5%) showed IDC. Grade assignment of IDC led to a Grade Group change in 17 (1.6%) cases: four of 486 (0.8%) Grade Group 1 cases were reclassified as Grade Group 2, nine of 375 (2.4%) Grade Group 2 cases were reclassified as Grade Group 3, and four of 58 (6.9%) Grade Group 4 cases were reclassified as Grade Group 5. IDC was observed in 213 of 835 (25.5%) radical prostatectomies, and its grading led to a change in tumour grade in five of 835 (0.6%) patients, with upgrading in two of 207 (1.0%) patients with Grade Group 1 cancer, in two of 420 (0.5%) patients with Grade Group 2 cancer, and in one of 50 (2%) patients with Grade Group 4 cancer.

CONCLUSION

IDC grade assignment led to a Grade Group change in 1.6% of prostate biopsy specimens and in 0.6% of radical prostatectomy specimens. Although the inclusion of IDC in or the exclusion of IDC from the Grade Group might affect decision-making in individual patients, it has a minimal impact on overall prostate cancer management.

Detection of clinically significant prostate cancer in biopsy-naïve men: direct comparison of systematic biopsy, multiparametric MRI- and contrast-ultrasound-dispersion imaging-targeted biopsy

OBJECTIVES

To compare and evaluate a multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy (TBx) strategy, contrast-ultrasound-dispersion imaging (CUDI)-TBx strategy and systematic biopsy (SBx) strategy for the detection of clinically significant prostate cancer (csPCa) in biopsy-naïve men.

PATIENTS AND METHODS

A prospective, single-centre paired diagnostic study included 150 biopsy-naïve men, from November 2015 to November 2018. All men underwent pre-biopsy mpMRI and CUDI followed by a 12-core SBx taken by an operator blinded from the imaging results. Men with suspicious lesions on mpMRI and/or CUDI also underwent MRI-TRUS fusion-TBx and/or cognitive CUDI-TBx after SBx by a second operator. A non-inferiority analysis of the mpMRI- and CUDI-TBx strategies in comparison with SBx for International Society of Urological Pathology Grade Group [GG] ≥2 PCa in any core with a non-inferiority margin of 1 percentage point was performed. Additional analyses for GG ≥2 PCa with cribriform growth pattern and/or intraductal carcinoma (CR/IDC), and GG ≥3 PCa were performed. Differences in detection rates were tested using McNemar's test with adjusted Wald confidence intervals.

RESULTS

After enrolment of 150 men, an interim analysis was performed. Both the mpMRI- and CUDI-TBx strategies were inferior to SBx for GG ≥2 PCa detection and the study was stopped. SBx found significantly more GG ≥2 PCa: 39% (56/142), as compared with 29% (41/142) and 28% (40/142) for mpMRI-TBx and CUDI-TBx, respectively (P < 0.05). SBx found significantly more GG = 1 PCa: 14% (20/142) compared to 1% (two of 142) and 3% (four of 142) with mpMRI-TBx and CUDI-TBx, respectively (P < 0.05). Detection of GG ≥2 PCa with CR/IDC and GG ≥3 PCa did not differ significantly between the strategies. The mpMRI- and CUDI-TBx strategies were comparable in detection but the mpMRI-TBx strategy had less false-positive findings (18% vs 53%).

CONCLUSIONS

In our study in biopsy-naïve men, the mpMRI- and CUDI-TBx strategies had comparable PCa detection rates, but the mpMRI-TBX strategy had the least false-positive findings. Both strategies were inferior to SBx for the detection of GG ≥2 PCa, despite reduced detection of insignificant GG = 1 PCa. Both strategies did not significantly differ from SBx for the detection of GG ≥2 PCa with CR/IDC and GG ≥3 PCa.

Expansile cribriform Gleason pattern 4 has histopathologic and molecular features of aggressiveness and greater risk of biochemical failure compared to glomerulation Gleason pattern 4

BACKGROUND

Molecular testing of prostate cancer biopsies with Gleason pattern 4 suggests the expansile cribriform pattern is more aggressive than the glomerulation pattern. These two extreme patterns have not been compared at prostatectomy. We hypothesized that at prostatectomy the expansile cribriform pattern would be associated with histopathologic and molecular features of aggressiveness and with greater risk of biochemical recurrence (BCR) than the glomerulation pattern.

METHODS

In a retrospective cohort study, radical prostatectomy reports with expansile cribriform pattern or glomerulation pattern were analyzed for percentage of total pattern 4, extraprostatic extension (EPE), positive lymph nodes, seminal vesicle invasion (SVI), and intraductal carcinoma (IDC). Cases with pattern 5 or with both expansile cribriform and glomerulations patterns present were excluded. The electronic medical record was reviewed for BCR-free survival and for Decipher test results.

RESULTS

Of 1020 radical prostatectomies from July 2015 to July 2018, 110 (11%) had either expansile cribriform or glomerulation pattern present. The expansile cribriform group was associated with more histopathologic features of aggressiveness, with higher average total percentage pattern 4 (43.7 vs 27.0, P = .002), a trend of greater extensive EPE (32.7% vs 17.2%, P = .06), a trend toward statistical significance of higher rate of SVI (11.5% vs 3.4%, P = .1), greater positive lymph nodes (9.6% vs 0%, P = .02), and a higher percentage of cases with or suspicious for IDC (23.1% vs 8.6%, P = .04). The risk of BCR was 4.4 (1.3-15.4) fold greater for the expansile cribriform group vs the glomerulations group (P = .02). For the 38 patients who underwent Decipher testing, the expansile cribriform group had a high-risk assay category mean score whereas the glomerulations group had an average risk assay category mean score (0.61 vs 0.47, P = .02).

CONCLUSIONS

In a comparison of prostatectomy cases with expansile cribriform pattern to those with glomerulation pattern, the expansile cribriform pattern was associated with more histopathologic features of aggressiveness, greater risk of biochemical failure, and higher scores with a molecular classifier (Decipher) test. These findings underscore the importance of reporting the types of pattern 4 and supports the argument that men with expansile cribriform likely require more aggressive management.

MRI-directed high-frequency (29MhZ) TRUS-guided biopsies: initial results of a single-center study

OBJECTIVES

To evaluate the ability of high-frequency (29 MHz) transrectal micro-ultrasound (microUS) as a second-look examination after biparametric MRI (bp-MRI) and to reidentify focal lesions seen on diagnostic MRI and to detect new ones METHODS: A total of 118 consecutive men (mean age, 66 ± 13 [SD] years; range, 49-93 years) with a mean prostate-specific antigen level of 11 ± 19 (SD) ng/mL (range, 2-200 ng/mL) and at least one focal lesion (MRI+) with a score > 2 on bp-MRI were included. Of these, 79/118 (66.9%) were biopsy-naïve and 102/118 (86.5%) had non-suspicious rectal examination. All patients had MRI-directed microUS-guided biopsy using a 29-MHz transducer. All lesions visible on micro-ultrasound (microUS+) were targeted without image fusion, which was only used for MRI+/microUS- lesions. Significant prostate cancer (sPCa) was defined by a Gleason score ≥ 7 or a maximum cancer core length > 3 mm.

RESULTS

A total of 144 focal prostatic lesions were analyzed, including 114 (114/144, 79.2%) MRI+/microUS+ lesions, 13 MRI+/microUS- lesions (13/144, 9%), and 17 MRI-/microUS+ lesions (17/144, 11.8%). Significant PCa was detected in 70 MRI+/microUS+ lesions (70/114, 61.4%), in no MRI+/microUS- lesion (0/13, 0%), and in 4 MRI-/microUS+ lesions (4/17, 23.5%). The sensitivity and specificity of microUS on a per-patient and a per-lesion basis were 100% (95% CI, 84.9-100%) and 22.8% (95% CI, 12.5-35.8%) and 100% (95% CI, 85.1-100%) and 22.6% (95% CI, 12.3-36.2%), respectively.

CONCLUSION

MicroUS, as a second-look examination, may show promise to localize targets detected on bp-MRI.

KEY POINTS

• Used as a second-look examination, microUS-guided biopsies have a 100% detection rate of sCa originating in the PZ or lower third of the TZ, without microUS-MRI image fusion. • MicroUS results may provide additional information about lesions visible on MRI. • MicroUS may provide the ability to detect small PZ lesions undetected by bp-MRI.

Cases Having a Gleason Score 3+4=7 With <5% of Gleason Pattern 4 in Prostate Needle Biopsy Show Similar Failure-free Survival and Adverse Pathology Prevalence to Gleason Score 6 Cases in a Radical Prostatectomy Cohort

Recent discussions have suggested expanding the inclusion criteria for active prostate cancer surveillance to include cases with a Gleason score (GS) of 3+4=7. In this study, we examined this proposed use of a limited percent Gleason pattern 4 (%GP4) to identify candidates of active surveillance among 315 patients who underwent radical prostatectomy for prostate cancer with a GS of 6 or 3+4=7 via needle biopsy. The latter cases were divided into 4 groups using highest or overall %GP4 cut-off values of 5% and 10% as determined from prostate needle biopsies. The frequency of adverse pathology and risk of biochemical recurrence were compared between the GS 6 and both GS 3+4=7 groups. Adverse pathology was defined as a GS 4+3=7 or higher, pT3b staging or positive lymph node metastasis. Notably, the Gleason pattern 4 <5% and GS 6 groups did not differ significantly in terms of the frequency of adverse pathology and risk of biochemical recurrence by the highest method. However, other highest Gleason pattern 4 categories had significantly higher frequencies and risks. Using the overall method, even the Gleason pattern 4 <5% group had a significantly higher frequency of adverse pathology and risk of biochemical recurrence relative to the GS 6 group. In conclusion, our findings suggest that patients with a GS 3+4=7 on biopsy with a highest %GP4 <5% are similar candidates for active surveillance to men with GS 6 cancers.

Volume of Gleason pattern 4 stratifies risk of metastasis and death in patients with Gleason score 3+5=8/5+3=8 positive prostate core biopsies

Implementation of Grade Groups (GrGrs) has been widely accepted for reporting prostate cancer grade since the 2014 International Society of Urological Pathology consensus meeting. Despite their undisputed value for risk stratification, some GrGr are, a priori, quite heterogeneous in that they contain multiple Gleason patterns (GPs). In this regard, the prognostic significance of GP5 in biopsies with highest GrGr4 is uncertain and evaluated in this study. A search of all core biopsies positive for prostate cancer reviewed after 2005 was performed, and 71 cases with highest GrGr4 containing GP5 (i.e., 3 + 5 = 8 or 5 + 3 = 8; referred to as GrGr4/GP5pos) eligible for inclusion were identified. In addition, 95 core biopsy cases with highest GrGr4 and no GP5 (i.e, 4 + 4 = 8; referred to as GrGr4/GP5neg) were selected for comparison. Multiple pathologic parameters, including volume and amount of GP4, and clinical variables were collected to evaluate the influence of GP5 on disease recurrence, development of metastases, and disease-specific death. GrGr4/GP5pos cases did not show, as a group, statistically significant differences in prostatectomy findings, disease recurrence, metastases, and disease-specific mortality when compared with GrGr4/GP5neg cases. In addition, the risk of all outcomes evaluated in the study did not differ between the whole GrGr4/GP5pos and GrGr4/GP5neg groups. However, Kaplan-Meier analysis found that GrGr4/GP5pos cases with a significant amount of GP4 did show a higher risk of prostate cancer-specific death as well as bone and visceral metastases. Univariate Cox regression demonstrated that preoperative prostate specific antigen (PSA), total number of positive cores, and global GrGr5 were also associated with a higher chance of disease-specific death. In a multivariate model, only global GrGr5 and PSA >20 ng/dL remained statistically significant. This study suggests that the mere presence of GP5 in core biopsies with highest GrGr4 disease may not portend a worse prognosis. In these cases, accounting for the case-wide volume of GP4 by reporting a global GrGr appears to be more relevant as it identifies a subset of GrGr4/GP5pos patients with global GrGr5 who have a higher risk of metastases and prostate cancer-specific mortality.

Correlation between cribriform/intraductal prostatic adenocarcinoma and percent Gleason pattern 4 to a 22-gene genomic classifier

BACKGROUND

The Decipher test measures expression of 22 RNA biomarkers associated with aggressive prostate cancer used to improve risk stratification of patients to help guide management. To date, Decipher's genomic classification has not been extensively correlated with specific histologic growth patterns in prostatic adenocarcinoma. With a growing understanding of the clinical aggressiveness associated with cribriform growth pattern (CF), intraductal carcinoma (IDC), and percent Gleason pattern 4 (G4%), we sought to determine if their presence was associated with an increased genomic risk as measured by the Decipher assay.

DESIGN

Clinical use of the Decipher assay was performed on the highest Gleason score (GS) tumor nodule of prostatectomy specimens from a prospective cohort of 48 patients, with GS varying from 7 through 9 to help guide clinical risk stratification. The tumors were reviewed for CF, IDC, and G4%, which were then compared to the Decipher score (0-1) and risk stratification (high vs not high).

RESULTS

The presence of CF/IDC was significantly associated with Decipher risk score (P = .007), with a high-risk Decipher score in 22% vs 56% of patients without or with CF/IDC. On binary logistic regression analysis, G4% (odds ratio [OR] 1.04 per percent increase [95% confidence interval [CI], 1.02-1.06]; P = .0004) and CF predominant (OR, 9.60 [95%CI, 1.48-62.16]; P = .02) were significantly associated with a high-risk GC score. IDC did not reach significance (OR, 1.92 [95%CI, 0.65-5.67]; P = .24).

CONCLUSIONS

Our findings add to an expanding knowledge base that supports G4% and CF/IDC as molecularly unique and clinically relevant features in prostatic adenocarcinoma. These histologic features should be standardly reported as they are associated with more aggressive prostate cancer. Future work should determine the independent information of these histologic findings that are relative to genomic assessment on long-term outcomes.

Cribriform pattern and perineural invasion on MR/US fusion biopsy predict failure of selection criteria for prostatic hemigland ablation

OBJECTIVES

To assess clinicopathologic factors on MR/US fusion biopsy that might predict failure of theoretical selection criteria for prostatic hemigland ablation (HA).

SUBJECTS AND METHODS

A retrospectively maintained single institution multiparametric MRI database (n = 1667) was queried to identify 355 patients who underwent MR/US fusion biopsy, including both targeted biopsy and concurrent systematic biopsy from December 1, 2014 to June 1, 2018. Clinical, pathological, and imaging variables were assessed on fusion biopsy (Table 1) to determine who met theoretical selection criteria for HA, defined as unilateral intermediate-risk prostate cancer per NCCN criteria (Grade Group [GG] 2 or 3 with prostate-specific antigen <20) and no evidence of extraprostatic extension (EPE) on multiparametric MRI. Predictors of selection criteria failure were then assessed in patients who also underwent radical prostatectomy (RP). Failure of the theoretical HA selection criteria was defined as presence of GG ≧ 2 on the contralateral (untreated) side, or the presence of high-risk disease (any GG ≧ 4 or EPE) in the RP specimen.

RESULTS

Of the 355 patients who underwent fusion biopsy, 84 patients met the theoretical selection criteria for HA. Of those patients eligible, 54 underwent RP, 37 (68.5%) of which represented unsuccessful HA selection criteria. Patients no longer met HA selection criteria on the basis of upgrading alone in 6/54 (11.1%), EPE alone in 9/54 (16.7%), bilateral GG 2 or 3 in 16/54 (29.6%) or combined EPE and bilateral GG 2 or 3 in 6/54 (11.1%) cases. In the HA selection failures due to upgrading, three also had EPE, one of whom also had missed contralateral GG ≧ 2 disease. The only factor independently associated with HA failure was any presence of cribriform pattern (HR 7.01, P = 0.021). Perineural invasion on systematic biopsyalso appeared to improve the performance of our multivariable model (HR 5.33, P = 0.052), though it was not statistically significant when using a cutoff of <0.05. Accuracy for predicting successful HA was 0.32 and improved to 0.74 if PNI or cribriform were excluded and 0.84 if both were excluded.

CONCLUSIONS

In a retrospective analysis of RP patients who underwent preoperative MRI/US fusion biopsy, current selection criteria for prostatic HA based on NCCN intermediate-risk stratification failed to accurately identify appropriate candidates in 68.5% of patients. Cribriform pattern and PNI detected on biopsy reduced the failure of hemigland selection criteria to 43%. These criteria should be routinely reported on biopsy pathology and taken into consideration when selecting patients for HA in prospective clinical trials.

Histological differences in cancer cells, stroma, and luminal spaces strongly correlate with in vivo MRI-detectability of prostate cancer

The current study aimed to investigate the plausible histopathological factors that affect the detectability of prostate cancers on multiparametric magnetic resonance imaging (MP-MRI). This retrospective study included 59 consecutive patients who had undergone MP-MRI and subsequent radical prostatectomy. The cases were standardized according to the tumor size ranging from 10 to 20 mm on the final pathological diagnosis. Histopathological review and semi-automated imaging analysis were performed to evaluate the relative area fractions of the histological components, including cancer cells, stroma, and luminal spaces. Among the 59 prostatectomy specimens, no case showed two or more foci of cancer that matched the size criteria. Of the 59 lesions, 35 were MRI-detectable [Prostate Imaging Reporting and Data System (PIRADS) score of 3 or greater] and 24 were MRI-undetectable (PIRADS score of 2 or less). No significant differences were observed in Gleason Grade Group, percentage of Gleason pattern 4, and predominant subtype of Gleason pattern 4 between MRI-detectable and MRI-undetectable cancers. On the other hand, significantly higher mean area fraction of cancer cells (60.9% vs. 42.7%, P < 0.0001) and lower mean area fractions of stroma (33.8% vs. 45.1%, P = 0.00089) and luminal spaces (5.2% vs. 12.2%, P < 0.0001) were observed in MRI-detectable cancers than in MRI-undetectable cancers. In a multivariable analysis performed upon exclusion of area fraction of stroma due to its multicollinearity with that of cancer cells, area fractions of cancer cells (P = 0.0031) and luminal space (P = 0.0035) demonstrated strong positive and negative correlation with MRI-detectability, respectively. Changes in cancer cells, stroma, and luminal spaces, rather than conventional histological parameters, could be considered one of the best predictors to clinical, in vivo MRI-detectability of 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.