On cribriform prostate cancer

Artificial intelligence applications in prostate cancer

Artificial intelligence (AI) applications have enabled remarkable advancements in healthcare delivery. These AI tools are often aimed to improve accuracy and efficiency of histopathology assessment and diagnostic imaging interpretation, risk stratification (i.e., prognostication), and prediction of therapeutic benefit for personalized treatment recommendations. To date, multiple AI algorithms have been explored for prostate cancer to address automation of clinical workflow, integration of data from multiple domains in the decision-making process, and the generation of diagnostic, prognostic, and predictive biomarkers. While many studies remain within the pre-clinical space or lack validation, the last few years have witnessed the emergence of robust AI-based biomarkers validated on thousands of patients, and the prospective deployment of clinically-integrated workflows for automated radiation therapy design. To advance the field forward, multi-institutional and multi-disciplinary collaborations are needed in order to prospectively implement interoperable and accountable AI technology routinely in clinic.

The presence of cribriform pattern in prostate biopsy and radical prostatectomy is associated with negative postoperative pathological features

Introduction

Prostate cancer is the second most common male cancer worldwide. Its rising incidence and high overtreatment rate drive the search for new prognostic factors. Histopathological variants, such as cribriform pattern (CP), are associated with poorer oncologic outcome. The aim of this study was to assess the correlation between CP in prostate biopsy and radical prostatectomy (RP) and postoperative pathological features.

Material and methods

In this retrospective, single-centre study we analysed the reviewed medical records of 100 men who underwent minimally invasive RP in the years 2017-2019. RP histopathological examination was performed by a single expert pathologist, and preoperative biopsies were assessed by various professionals from different referral centres.

Results

48% of men underwent endoscopic RP with limited lymphadenectomy, whereas 52% underwent laparoscopic RP with extended lymphadenectomy. CP in biopsy was present in 6 patients: 3 in each of both groups (6.3% and 5.8%, respectively). Lymph node metastases were present in 50% and 10% of patients with and without CP in biopsy, respectively (p = 0.028). Postoperative histopathological examination revealed CP in 65%. CP in RP was associated with higher International Society of Urological Pathology (ISUP) (p < 0.001), extraprostatic extension (EPE) (p = 0.001), seminal vesicle invasion (SVI) (p = 0.001), and positive surgical margin (PSM) (p = 0.004). Thirteen (20%) of the patients with CP in the RP specimen had lymph node metastasis, and none of the patients without CP in the RP specimen had regional LN metastasis.

Conclusions

The presence of CP in a biopsy specimen and RP is associated with negative postoperative features. Therefore, efforts should be made to increase CP reporting in biopsies because its identification could trigger a more radical surgical approach with extended lymphadenectomy.

Enhancing PSMA PET/CT imaging of prostate cancer: investigating the impact of multiple time point evaluation, diuretic administration, cribriform pattern, and intraductal carcinoma

OBJECTIVE

Our objective was to correlate staging PSMA PET imaging parameters to final histopathology. Second objective was to assess the performance of standard versus delayed PSMA PET to detect primary prostate tumor.

METHODS

Thirty-one patients (mean age, 61.4 ± 8.2) who underwent radical prostatectomy and preoperative staging PSMA PET scans were included in the study. After defining dominant lesion in pathology, correlations with PET images were performed. Additionally, two physicians blind to clinical and pathological information retrospectively reviewed staging Ga-68 PSMA PET scans with standard and delayed imaging.

RESULTS

Dominant lesion SUV's increased with time 8.2(± 4.5), 10(± 7.1), and 10.2(± 7.8) at 1, 2, and 3 h (P = .03 T1-T3). WHO Grade group 3 had highest SUV (group 3 11.9 ± 5.6 vs. group 2 7.9 ± 1.5, p = .02). Addition of cribriform pattern on intraductal component was associated with higher SUV's (11 ± 2.9 vs. 6.5 ± 2.1, p = .01) and higher Gleason four ratios (64 ± 9% vs. 37 ± 17%, p = .01). Intraductal carcinoma was associated with larger tumors (6.3 ± 2.3 cm3 vs. 2.6 ± 1.7 cm3, p < .001). Physician sensitivities ranged from 61 to 81%. Excluding Gleason 3 + 3 lesions and small lesions (< 1 cm3), sensitivities increased to 80-100%. Differences of sensitivity between different time points were not significant. Combined evaluation of all time points did not increase sensitivity.

CONCLUSIONS

Cribriform pattern correlates with higher Gleason 4 ratios and SUVs in PSMA PET. Intraductal carcinoma is associated with larger tumors but not higher Gleason 4 ratios and SUVs. Multiple late imaging times did not enhance tumor detection and may pose tolerability issues for some patients.

DNA Damage Repair Pathways in Prostate Cancer: A Narrative Review of Molecular Mechanisms, Emerging Biomarkers and Therapeutic Targets in Precision Oncology

Prostate cancer (PCa) has a distinct molecular signature, including characteristic chromosomal translocations, gene deletions and defective DNA damage repair mechanisms. One crucial pathway involved is homologous recombination deficiency (HRD) and it is found in almost 20% of metastatic castrate-resistant PCa (mCRPC). Inherited/germline mutations are associated with a hereditary predisposition to early PCa development and aggressive behavior. BRCA2, ATM and CHECK2 are the most frequently HRD-mutated genes. BRCA2-mutated tumors have unfavorable clinical and pathological characteristics, such as intraductal carcinoma. PARP inhibitors, due to the induction of synthetic lethality, have been therapeutically approved for mCRPC with HRD alterations. Mutations are detected in metastatic tissue, while a liquid biopsy is utilized during follow-up, recognizing acquired resistance mechanisms. The mismatch repair (MMR) pathway is another DNA repair mechanism implicated in carcinogenesis, although only 5% of metastatic PCa is affected. It is associated with aggressive disease. PD-1 inhibitors have been used in MMR-deficient tumors; thus, the MMR status should be tested in all metastatic PCa cases. A surrogate marker of defective DNA repair mechanisms is the tumor mutational burden. PDL-1 expression and intratumoral lymphocytes have ambivalent predictive value. Few experimental molecules have been so far proposed as potential biomarkers. Future research may further elucidate the role of DNA damage pathways in PCa, revealing new therapeutic targets and predictive biomarkers.

Prostate Cancer Morphologies: Cribriform Pattern and Intraductal Carcinoma Relations to Adverse Pathological and Clinical Outcomes-Systematic Review and Meta-Analysis

The present study aimed to assess the association between the cribriform pattern (CP)/intraductal carcinoma (IDC) and the adverse pathological and clinical outcomes in the radical prostatectomy (RP) cohort. A systematic search was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement (PRISMA). The protocol from this review was registered on the PROSPERO platform. We searched PubMed^®, the Cochrane Library and EM-BASE^® up to the 30th of April 2022. The outcomes of interest were the extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node metastasis (LNS met), risk of biochemical recurrence (BCR), distant metastasis (MET) and disease-specific death (DSD). As a result, we identified 16 studies with 164 296 patients. A total of 13 studies containing 3254 RP patients were eligible for the meta-analysis. The CP/IDC was associated with adverse outcomes, including EPE (pooled OR = 2.55, 95%CI 1.23-5.26), SVI (pooled OR = 4.27, 95%CI 1.90-9.64), LNs met (pooled OR = 6.47, 95%CI 3.76-11.14), BCR (pooled OR = 5.09, 95%CI 2.23-11.62) and MET/DSD (pooled OR = 9.84, 95%CI 2.75-35.20, p < 0.001). In conclusion, the CP/IDC belong to highly malignant prostate cancer patterns which have a negative impact on both the pathological and clinical outcomes. The presence of the CP/IDC should be included in the surgical planning and postoperative treatment guidance.

Single cell analysis of cribriform prostate cancer reveals cell intrinsic and tumor microenvironmental pathways of aggressive disease

Cribriform prostate cancer, found in both invasive cribriform carcinoma (ICC) and intraductal carcinoma (IDC), is an aggressive histological subtype that is associated with progression to lethal disease. To delineate the molecular and cellular underpinnings of ICC/IDC aggressiveness, this study examines paired ICC/IDC and benign prostate surgical samples by single-cell RNA-sequencing, TCR sequencing, and histology. ICC/IDC cancer cells express genes associated with metastasis and targets with potential for therapeutic intervention. Pathway analyses and ligand/receptor status model cellular interactions among ICC/IDC and the tumor microenvironment (TME) including JAG1/NOTCH. The ICC/IDC TME is hallmarked by increased angiogenesis and immunosuppressive fibroblasts (CTHRC1⁺ASPN⁺FAP⁺ENG⁺) along with fewer T cells, elevated T cell dysfunction, and increased C1QB⁺TREM2⁺APOE⁺-M2 macrophages. These findings support that cancer cell intrinsic pathways and a complex immunosuppressive TME contribute to the aggressive phenotype of ICC/IDC. These data highlight potential therapeutic opportunities to restore immune signaling in patients with ICC/IDC that may afford better outcomes.

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.

Trends in disagreement with outside genitourinary pathology diagnoses at an academic center

AIMS

To evaluate the frequencies and types of disagreements in a contemporary urological second-opinion consult service in order to improve pathologist awareness.

METHODS

For 7 years ending 30 October 2021, records were kept of our department's total urologic outside consultation and disagreed-upon cases. Disagreements were categorized according to specimen type and nature of conflict. All grading and staging assignments used International Society of Urological Pathology (ISUP) criteria. Statistical analyses for each specimen type included the percent disagreement. Cohen's kappa analysis was done to measure interrater reliability on the prostate biopsies, prostatectomies, and the bladder biopsies/resections. In addition, for the prostate biopsies, the potential for change in treatment candidacy calculation (CTC), was assessed as sum of changes from cancer to non-malignant tissue or the reverse, plus changes from Gleason Grade group (GG)1 to GG ≥ 2 (3 +4 =7) or the reverse.

RESULTS

Overall mean disagreement rate for all specimens was 15.2%. The highest rate was among 1545 prostate biopsy cases, where 410 contained disagreements (26.5%). 118 (7.6%) met criteria for CTC: 10 cases were altered from cancer to non-cancer, 38 cases downgraded from GG≥ 2 to GG1, and 70 upgraded from GG1 to GG≥ 2. Second opinion downgraded the overall highest GG more often than it upgraded it, with downgrade:upgrade ratios of 64:37 for the GG1/GG2 threshold, 79:67 for the GG2/GG3, and 14:0 for the GG3/GG4. 146 specimen parts had disagreements as to cancer vs. suspicious vs. benign, with 85 undercalled and 61 overcalled. Other rates of disagreement included: prostatectomy 34/198 (17.2%); bladder resection or biopsy 68/591 (11.5%); kidney 27/175 (15.4%); and orchiectomy 9/82 (11.0%). In bladder specimens, overgrading was 6X more frequent than undergrading; and overstaging muscularis propria invasion was 6X more frequent than understaging.

CONCLUSIONS

The review of uropathologic materials before definitive therapy can lead to changes that impact clinical decisions significantly. As an example, for prostate biopsies, candidacy for active surveillance versus definitive treatment hinges on GG1 versus 2 and this distinction constituted most CTC cases. The above findings highlight aspects of urological pathology to be emphasized to residents in training, and pathologists in practice.

Cribriform Patterned Lesions in the Prostate Gland with Emphasis on Differential Diagnosis and Clinical Significance

Simple Summary

A cribriform structure is defined as a continuous proliferation of cells with intermingled lumina. Various entities may have a cribriform morphology within the prostate gland, ranging from normal, to benign, to borderline and even to malignant lesions. This review summarizes the morphologic features of entities that have a cribriform morphology within the prostate gland, with an emphasis on their differential diagnosis, molecular profile and clinical significance. The basic aim is to assist the pathologist with challenging and controversial cases and inform the clinician on the clinical implications of cribriform morphology.

Abstract

Cribriform glandular formations are characterized by a continuous proliferation of cells with intermingled lumina and can constitute a major or minor part of physiologic (normal central zone glands), benign (clear cell cribriform hyperplasia and basal cell hyperplasia), premalignant (high-grade prostatic intraepithelial neoplasia), borderline (atypical intraductal cribriform proliferation) or clearly malignant (intraductal, acinar, ductal and basal cell carcinoma) lesions. Each displays a different clinical course and variability in clinical management and prognosis. The aim of this review is to summarize the current knowledge regarding the morphological features, differential diagnosis, molecular profile and clinical significance of the cribriform-patterned entities of the prostate gland. Areas of controversy regarding their management, i.e., the grading of Intaductal Carcinoma, will also be discussed. Understanding the distinct nature of each cribriform lesion leads to the correct diagnosis and ensures accuracy in clinical decision-making, prognosis prediction and personalized risk stratification of patients.

Looking for a Simplified Diagnostic Model to Identify Potentially Lethal Cases of Prostate Cancer at Initial Diagnosis: An ImGO Pilot Study

The recurrent genetic anomalies used to classify prostate cancer (PC) into distinct molecular subtypes have limited relevance for clinical practice. In consideration of WHO 2016 histological classification, which includes the introduction of Gleason Score 4 for patients with cribriform component and the definition of intraductal carcinoma as a new entity, a retrospective pilot study was conducted to investigate, by histological review, if there were any variations of Gleason Score and the incidence of intraductal carcinoma and cribriform pattern, intended as “phenotypic” markers of potentially lethal PC, among metastatic castration-sensitive PC (mCSPC) and metastatic castration-resistant PC (mCRPC) samples. Potentially predictive factors were also assessed. Among 125 cases, a variation in the Gleason Score was reported in 26% of cases. A cribriform (36%) or intraductal (2%) pattern was reported in a higher percentage. Of them, a primary Gleason pattern 4 was reported in 80% of cases. All patients with intraductal carcinoma present a BRCA2 mutation, also found in 80% of cases with a cribriform pattern. This pilot study documented some hypothesis-generating data, as the evaluation of de novo mCSPC and mCRPC as phenotypic/biologic model to be translated in clinical practice. A cribriform pattern/intraductal carcinoma might be a marker of potentially lethal PC. The high incidence of TP53 and BRCA2 mutations in de novo mCSPC may also have a therapeutic implication.

Prostate Pathology: What is New in the 2022 WHO Classification of Urinary and Male Genital Tumors?

In 2022, after a six-year interval, the International Agency for Research on Cancer (IARC) has published the 5th edition of the WHO Classification of Urinary and Male Genital Tumors, which provides a comprehensive update on tumor classification of the genitourinary system. This review article focuses on prostate carcinoma and underscores changes in the prostate chapter as well as those made across the entire series of the 5th edition of WHO Blue Books. Although no major alterations were made to this chapter, some of the most notable updates include restructure of contents and introduction of a new format; standardization of mitotic counts, genomic nomenclatures, and units of length; refined definition for the terms "variant", "subtype", and "histologic pattern"; reclassification of prostatic intraepithelial neoplasia (PIN)-like adenocarcinoma as a subtype of prostatic acinar adenocarcinoma; and recognition of treatment-related neuroendocrine prostatic carcinoma as a distinct tumor type. Evolving and unsettled issues related to grading of intraductal carcinoma of the prostate and reporting of tertiary Gleason pattern, the definition and prognostic significance of cribriform growth pattern, and molecular pathology of prostate cancer will also be covered in this review.

Contemporary Grading of Prostate Cancer: The Impact of Grading Criteria and the Significance of the Amount of Intraductal Carcinoma

(1) Background: Prognostic grade group (PGG) is an important prognostic parameter in prostate cancer that guides therapeutic decisions. The cribriform pattern and intraductal carcinoma (IDC) are two histological patterns, that have additional prognostic significance. However, discrepancies exist regarding the handling of IDC according to the guidelines published by two international genitourinary pathology societies. Furthermore, whether, in addition to its presence, the amount of IDC is also of importance has not been studied before. Lastly, the handling of tertiary patterns has also been a matter of debate in the literature. (2) Methods: A total of 129 prostatectomy cases were retrieved and a detailed histopathologic analysis was performed. (3) Results: Two cases (1.6%) upgraded their PGG, when IDC was incorporated in the grading system. The presence and the amount of IDC, as well as the presence of cribriform carcinoma were associated with adverse pathologic characteristics. Interestingly, in six cases (4.7%) there was a difference in PGG when using the different guidelines regarding the handling of tertiary patterns. In total, 6.2% of the cases would be assigned a different grade depending on the guidelines followed. (4) Conclusions: These findings highlight a potential area of confusion among pathologists and clinicians and underscore the need for a consensus grading system.

ISUP Consensus Definition of Cribriform Pattern Prostate Cancer

The presence of a cribriform pattern is now recognized as a clinically important, independent adverse prognostic indicator for prostate cancer. For this reason the International Society of Urological Pathology (ISUP) recently recommended its inclusion in standard reporting. In order to improve interobserver agreement as to the diagnosis of cribriform patterns, the ISUP assembled an international panel of 12 expert urogenital pathologists for the purpose of drafting a consensus definition of cribriform pattern in prostate cancer, and provide their opinions on a set of 32 images and on potential diagnostic criteria. These images were selected by the 2 nonvoting convenors of the study and included the main categories where disagreement was anticipated. The Delphi method was applied to promote consensus among the 12 panelists in their review of the images during 2 initial rounds of the study. Following a virtual meeting, convened to discuss selected images and diagnostic criteria, the following definition for cribriform pattern in prostate cancer was approved: "A confluent sheet of contiguous malignant epithelial cells with multiple glandular lumina that are easily visible at low power (objective magnification ×10). There should be no intervening stroma or mucin separating individual or fused glandular structures" together with a set of explanatory notes. We believe this consensus definition to be practical and that it will facilitate reproducible recognition and reporting of this clinically important pattern commonly seen in prostate cancer. The images and the results of the final Delphi round are available at the ISUP website as an educational slide set (https://isupweb.org/isup/blog/slideshow/cribriform-slide-deck/).

Clinicopathological Analysis of the ISUP Grade Group And Other Parameters in Prostate Cancer: Elucidation of Mutual Impact of the Various Parameters

Background

Prostate cancer has become increasingly common worldwide. Although Grade group (GG) is widely accepted as an indicator of prostate cancer grade, there are malignancies that cannot be defined by GG alone. Moreover, the relationship between GG and other parameters remains unclear. Herein, we aimed to explore the biological characteristics of prostate cancer.

Methods

This study included 299 radical prostatectomy cases. The Chi-square test and analysis of variance were used to analyze the association of GG with binary and continuous variables. We then conducted morphological analyses. Multivariate analyses were performed to extract the data on risk factors for biochemical recurrence (BCR) and lymph node metastasis.

Results

The lymphatic, venous, perineural, and seminal vesicle invasion rates were 37/299 (12.4%), 25/299 (8.4%), 280/299 (93.6%), and 23/299 (7.7%), respectively. The extraprostatic extension (EPE), positive surgical margin, tertiary Gleason pattern 5, intraductal carcinoma of the prostate gland, and lymph node metastasis rates were 89/299 (29.8%), 106/299 (35.5%), 33/260 (12.7%), 56/299 (18.7%), and 23/299 (7.7%), respectively. As GG increased, various parameters became easier to visualize; however, there were differences between the parameters. Postoperative BCR was observed in 31/242 (12.8%) cases without preoperative hormone therapy; GG2, GG3, GG4, and GG5 accounted for 4, 7, 7, and 13 cases, respectively. Multivariate analyses revealed that GG and tumor diameter were significant risk factors for early BCR, whereas lymphatic invasion, EPE, and seminal vesicle invasion were significant risk factors for lymph node metastasis. For BCR, the odds ratios (ORs) for GG and tumor diameter were 2.253 (95% confidence interval (CI]): 1.297–3.912; P=0.004) and 1.074 (95% CI: 1.011–1.142; P=0.022), respectively. For lymph node metastasis, ORs for the presence of lymphatic invasion, EPE, and seminal vesicle invasion were 7.425 (95% CI: 1.688–22.583; P=0.004), 4.391 (95% CI: 1.037–18.589; P=0.044), and 5.755 (95% CI: 1.308–25.316; P=0.021), respectively.

Conclusions

We summarized various parameters correlating with each GG. Through multivariate analyses, we established the independent risk factors for early BCR and lymph node metastasis. In addition to GG, other important indices of malignancy were determined and weighted to provide a basis for future investigations.

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.

A distinct repertoire of cancer-associated fibroblasts is enriched in cribriform prostate cancer

Outcomes for men with localized prostate cancer vary widely, with some men effectively managed without treatment on active surveillance, while other men rapidly progress to metastatic disease despite curative-intent therapies. One of the strongest prognostic indicators of outcome is grade groups based on the Gleason grading system. Gleason grade 4 prostate cancer with cribriform morphology is associated with adverse outcomes and can be utilized clinically to improve risk stratification. The underpinnings of disease aggressiveness associated with cribriform architecture are not fully understood. Most studies have focused on genetic and molecular alterations in cribriform tumor cells; however, less is known about the tumor microenvironment in cribriform prostate cancer. Cancer-associated fibroblasts (CAFs) are a heterogeneous population of fibroblasts in the tumor microenvironment that impact cancer aggressiveness. The overall goal of this study was to determine if cribriform prostate cancers are associated with a unique repertoire of CAFs. Radical prostatectomy whole-tissue sections were analyzed for the expression of fibroblast markers (ASPN in combination with FAP, THY1, ENG, NT5E, TNC, and PDGFRβ) in stroma adjacent to benign glands and in Gleason grade 3, Gleason grade 4 cribriform, and Gleason grade 4 noncribriform prostate cancer by RNAscope®. Halo® Software was used to quantify percent positive stromal cells and expression per positive cell. The fibroblast subtypes enriched in prostate cancer were highly heterogeneous. Both overlapping and distinct populations of low abundant fibroblast subtypes in benign prostate stroma were enriched in Gleason grade 4 prostate cancer with cribriform morphology compared to Gleason grade 4 prostate cancer with noncribriform morphology and Gleason grade 3 prostate cancer. In addition, gene expression was distinctly altered in CAF subtypes adjacent to cribriform prostate cancer. Overall, these studies suggest that cribriform prostate cancer has a unique tumor microenvironment that may distinguish it from other Gleason grade 4 morphologies and lower Gleason grades.

Cribriform prostate cancer: Morphologic criteria enabling a diagnosis, based on survey of experts

Among four sub-patterns of Gleason grade 4 prostate cancer, voluminous evidence supports that the cribriform pattern holds an unfavorable prognostic impact, as compared with poorly-formed, fused, or glomeruloid. The International Society of Urological Pathology (ISUP) recommends specifying whether invasive grade 4 cancer is cribriform. Recently, ISUP experts published a consensus definition of cribriform pattern highlighting criteria that distinguish it from mimickers. The current study aimed to analyze morphologic features separately to identify those that define the essence of the cribriform pattern. Thirty-two selected photomicrographs were classified by 12 urologic pathologists as: definitely cribriform cancer, probably cribriform, unsure, probably not cribriform, or definitely not cribriform. Consensus was defined as 9/12 agree or disagree, with ≤1 strongly supporting the opposite choice. Final consensus was achieved in 21 of 32 cases. Generalized estimating equation (GEE) model with logit link was fitted to estimate effect of multiple morphologic predictors. Fisher exact test was used for categorical findings. Presence of intervening stroma precluded calling cribriform cancer (p = 0.006). Mucin presence detracted (p = 0.003) from willingness to call cribriform cancer (only 3 cases had mucin). Lumen number was associated with cribriform consensus (p = 0.0006), and all consensus cases had ≥9 lumens. Predominant papillary pattern or an irregular outer boundary detracted (p = NS). Invasive cribriform carcinoma should have absence of intervening stroma, and usually neither papillary pattern, irregular outer boundary, nor very few lumens. Setting the criteria for cribriform will help prevent over- or undercalling this important finding.

Prognostic significance of tertiary Gleason pattern in the contemporary era of Gleason grade grouping: A narrative review

Since the Gleason score was developed in 1966 as a histological classification for prostate cancer, it has been widely used in clinical practice and has evolved over time. The concept of a "tertiary Gleason pattern" (also known as a minor Gleason pattern) was first proposed in 2000, and has been used in clinical practice since the 2005 International Society of Urological Pathology conference. The prognostic significance of a tertiary Gleason pattern has been widely validated in various settings of prostate cancer, whereas its definition has yet to be fully established. Currently, a provisional definition of tertiary Gleason pattern is "<5% Gleason pattern 4 or 5 in radical prostatectomy specimens." In contrast, "Gleason grade grouping" was proposed in 2013 and came into use in clinical practice in 2016 according to the 2014 International Society of Urological Pathology conference. Although the prognostic significance of Gleason grade grouping has already been widely confirmed, it does not incorporate the concept of tertiary Gleason pattern. Recently, the 2019 International Society of Urological Pathology conference discussed how to handle tertiary Gleason pattern in the current Gleason scoring system, but no consensus was reached on the issue. This review summarizes the evidence on the prognostic significance of tertiary Gleason pattern and discusses how to deal with it in the context of the contemporary Gleason grade grouping. It also refers to reporting of the percentage of Gleason patterns 4 and 5, as well as quantitative Gleason score models incorporating tertiary Gleason pattern.

Going deeper through the Gleason scoring scale: An automatic end-to-end system for histology prostate grading and cribriform pattern detection

BACKGROUND AND OBJECTIVE

Prostate cancer is one of the most common diseases affecting men worldwide. The Gleason scoring system is the primary diagnostic and prognostic tool for prostate cancer. Furthermore, recent reports indicate that the presence of patterns of the Gleason scale such as the cribriform pattern may also correlate with a worse prognosis compared to other patterns belonging to the Gleason grade 4. Current clinical guidelines have indicated the convenience of highlight its presence during the analysis of biopsies. All these requirements suppose a great workload for the pathologist during the analysis of each sample, which is based on the pathologist's visual analysis of the morphology and organisation of the glands in the tissue, a time-consuming and subjective task. In recent years, with the development of digitisation devices, the use of computer vision techniques for the analysis of biopsies has increased. However, to the best of the authors' knowledge, the development of algorithms to automatically detect individual cribriform patterns belonging to Gleason grade 4 has not yet been studied in the literature. The objective of the work presented in this paper is to develop a deep-learning-based system able to support pathologists in the daily analysis of prostate biopsies. This analysis must include the Gleason grading of local structures, the detection of cribriform patterns, and the Gleason scoring of the whole biopsy.

METHODS

The methodological core of this work is a patch-wise predictive model based on convolutional neural networks able to determine the presence of cancerous patterns based on the Gleason grading system. In particular, we train from scratch a simple self-design architecture with three filters and a top model with global-max pooling. The cribriform pattern is detected by retraining the set of filters of the last convolutional layer in the network. Subsequently, a biopsy-level prediction map is reconstructed by bi-linear interpolation of the patch-level prediction of the Gleason grades. In addition, from the reconstructed prediction map, we compute the percentage of each Gleason grade in the tissue to feed a multi-layer perceptron which provides a biopsy-level score.

RESULTS

In our SICAPv2 database, composed of 182 annotated whole slide images, we obtained a Cohen's quadratic kappa of 0.77 in the test set for the patch-level Gleason grading with the proposed architecture trained from scratch. Our results outperform previous ones reported in the literature. Furthermore, this model reaches the level of fine-tuned state-of-the-art architectures in a patient-based four groups cross validation. In the cribriform pattern detection task, we obtained an area under ROC curve of 0.82. Regarding the biopsy Gleason scoring, we achieved a quadratic Cohen's Kappa of 0.81 in the test subset. Shallow CNN architectures trained from scratch outperform current state-of-the-art methods for Gleason grades classification. Our proposed model is capable of characterising the different Gleason grades in prostate tissue by extracting low-level features through three basic blocks (i.e. convolutional layer + max pooling). The use of global-max pooling to reduce each activation map has shown to be a key factor for reducing complexity in the model and avoiding overfitting. Regarding the Gleason scoring of biopsies, a multi-layer perceptron has shown to better model the decision-making of pathologists than previous simpler models used in the literature.

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

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

Isolated Intraductal Carcinoma of the Prostate in Prostatectomy Specimens: Report of 2 Cases and Review of the Literature

Intraductal carcinoma of the prostate (IDCp) is a distinct neoplastic entity, and although recognized for some time, it was included for the first time in the histologic classification of prostate cancer in the 2016 publication of World Health Organization. IDCp represents an intraductal or intra-acinar proliferation of malignant cells, with preservation of the basal cell layer. Even though IDCp is usually accompanied by a high-grade invasive component, low-grade invasive carcinoma can rarely be seen adjacent to the lesion. Even rarer is the incidence of isolated IDCp in needle biopsies, while a few such cases have been reported in prostatectomy specimens. We report 2 cases with isolated IDCp without any invasive component. A review of the literature is performed including the diagnostic challenges of IDCp and its morphologic mimics, immunohistochemical markers, molecular aspects, and prognostic implications. Even though it is not yet clear whether IDCp represents an intraductal spread of invasive cancer or a precursor of invasive carcinoma, the existence of isolated IDCp reinforces the idea that, at least in some of the cases, IDCp is a precancerous lesion. Further molecular studies need to be performed in order to clarify its pathogenesis.

Cribriform Pattern at the Surgical Margin is Highly Predictive of Biochemical Recurrence in Patients Undergoing Radical Prostatectomy

Objectives We investigated the relationship between cribriform patterns and biochemical recurrence in patients with positive surgical margins after radical prostatectomy. Methods This study was based on radical prostatectomy specimens obtained from 817 patients (165 with margin-positive status) collected at a single center between 2010 and 2016. We retrospectively analyzed and compared body mass index, preoperative prostate-specific antigen, Gleason score, operative methods, postoperative Gleason score, pathological T-stage, tumor percentage involvement, lymphatic and perineural invasion, prostate-specific antigen nadir, location and length of the positive margin, cribriform pattern status, and Gleason grade at the surgical margin in terms of their association with biochemical recurrence. Risk factors for biochemical recurrence were also investigated. Results 21% (31/146) of surgical margin-positive patients had a cribriform pattern. Nadir prostate-specific antigen, perineural invasion and biochemical recurrence rates were significantly higher in cribriform pattern present group than absent group (P = 0.031, 0.043 and 0.045, respectively). According to the Cox regression model, postoperative Gleason score, tumor percentage involvement, location and length of the positive margin, and the presence of a cribriform pattern at the surgical margin were significant predictive factors of biochemical recurrence (P = 0.022, &lt; 0.001, 0.015, 0.001, and 0.022, respectively). Moreover, the biochemical recurrence risk was approximately 3-fold higher in patients with a cribriform pattern at the surgical margin than in those without (HR: 3.41, 95% CI 1.20-9.70, P = 0.022). Conclusions A cribriform pattern at the surgical margin is a significant predictor of biochemical recurrence in patients who undergo radical prostatectomy.

Prostate cancer grading in 2018: limitations, implementations, cribriform morphology, and biological markers

The Gleason grading system is among the most important prognostic factors in patients with prostate cancer. From the 2005 to the 2014 consensus conferences, organized by the International Society of Urological Pathology, the morphologic criteria for the identification of the Gleason patterns were redefined, thus resulting in the shrinkage of the Gleason pattern 3. This led to the expansion of the Gleason pattern 4. The newly proposed grade group system reduces the Gleason scores of prostate cancer to the lowest number, each associated with a unique behavior from the prognostic point of view. The advantage is that the simplified system with five groups allows for a more accurate stratification of the patients in comparison with the Gleason system. Cribriform, fused, ill-defined and glomeruloid glands are part of the histologic spectrum of the Gleason pattern 4. Cribriform morphology has a prognosis that is worse in comparison with the other non-cribriform Gleason 4 patterns. One of the major implications of the cribriform growth is that it precludes a patient from choosing active surveillance.

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

INTRODUCTION

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