Analysis of 3D pathology samples using weakly supervised AI.

Human tissue, which is inherently three-dimensional (3D), is traditionally examined through standard-of-care histopathology as limited two-dimensional (2D) cross-sections that can insufficiently represent the tissue due to sampling bias. To holistically characterize histomorphology, 3D imaging modalities have been developed, but clinical translation is hampered by complex manual evaluation and lack of computational platforms to distill clinical insights from large, high-resolution datasets. We present TriPath, a deep-learning platform for processing tissue volumes and efficiently predicting clinical outcomes based on 3D morphological features. Recurrence risk-stratification models were trained on prostate cancer specimens imaged with open-top light-sheet microscopy or microcomputed tomography. By comprehensively capturing 3D morphologies, 3D volume-based prognostication achieves superior performance to traditional 2D slice-based approaches, including clinical/histopathological baselines from six certified genitourinary pathologists. Incorporating greater tissue volume improves prognostic performance and mitigates risk prediction variability from sampling bias, further emphasizing the value of capturing larger extents of heterogeneous morphology.

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

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

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.

Inter- and intraobserver agreement of programmed death ligand 1 scoring in head and neck squamous cell carcinoma, urothelial carcinoma and breast carcinoma.

AIMS: Programmed death-ligand 1 (PD-L1) expression by tumour cells (TC) is a mechanism for tumour immune escape through down-regulation of antitumour T cell responses and is a target for immunotherapy. PD-L1 status as a predictor of treatment response has led to the development of multiple biomarkers with different reference cut-offs. We assessed pathologist consistency in evaluating PD-L1 immunopositivity by examining the inter- and intraobserver agreement using various antibody clones and different cancer types. METHODS AND RESULTS: PD-L1 expression in TC and immune cells (IC) was manually scored in 27 head and neck squamous cell carcinoma (HSCC), 30 urothelial carcinoma (UC) and breast carcinoma (BC) using three commercial clones (SP263, SP142, 22C3) and one platform-independent test (E1L3N). For interobserver agreement, PD-L1 status was evaluated blindly by three pathologists. For intraobserver agreement, PD-L1 expression was re-evaluated following a wash-out period. Intraclass correlation coefficient (ICC), overall percentage agreement (OPA) and κ-values were calculated. Using clinical algorithms, the percentage of PD-L1-positive cases in HSCC, BC and UC were 15-81%, 47-67% and 7-43%, respectively. The percentage of PD-L1 positive cases relied heavily on the algorithm/cut-off values used. Almost perfect interobserver agreement was achieved using SP263 and E1L3N in HSCC, 22C3, SP142 and E1L3N in BC and 22C3 in UC. The SP142 clone in UC and HSCC showed moderate agreement and was associated with lower ICC and decreased intraobserver concordance. CONCLUSIONS: Excellent inter- and intraobserver agreement can be achieved using SP263, 22C3 and E1L3N, whereas PD-L1 scoring using SP142 clone is associated with a higher level of subjectivity.

Gleason grade patterns in nodal metastasis and corresponding prostatectomy specimens: impact on patient outcome.

AIMS: Lymph node metastases at the time of prostatectomy are an infrequent finding. The correlation of the pattern of nodal metastases with patient outcome has yet to be explored. METHODS AND RESULTS: Lymph node-positive prostatectomies were retrospectively reviewed. The presence of cribriform carcinoma (CC), intraductal carcinoma (IDC) and ISUP grade (G) were documented. The largest nodal metastasis was assessed for the morphological patterns present. G was assigned to the metastasis based on percentage morphological patterns present. Statistical analysis used spss to assess disease-specific survival (DSS), disease-free survival (DFS) and distant metastasis-free survival (DMFS). One hundred and ten cases were identified: G5 (n = 52), G4 (n = 8), G3 (n = 34), G2 (n = 10) and no G (n = 6; treatment effect). IDC or CC was present in 103 (94%) specimens. More than one positive node correlated with worse DFS [P = 0.012, hazard ratio (HR) = 1.951, 95% confidence interval (CI) = 1.142-3.331] and DMFS (P = 0.009, HR = 2.647, 95% CI = 1.239-5.651). G in the prostate and nodal metastasis were poorly correlated (kappa = 0.073, P = 0.195). The presence of pattern 5 was seen in 33 nodes (30%) and correlated with DFS (P = 0.020, HR = 1.903, 95% CI = 1.091-3.320), DSS (P = 0.021, HR = 5.937, 95% CI = 1.084-32.533) and DMFS (P = 0.007, HR = 2.695, 95% CI = 1.269-5.726). Nodal cribriform pattern showed no prognostic correlation and pattern 3 metastasis showed a significant trend towards better outcome (DMFS P = 0.033, HR = 0.431, 95% CI = 0.194-0.958). CONCLUSIONS: IDC or CC is identified in 94% of node-positive prostate cancers. Although G in the largest nodal metastasis has prognostic significance, its G does not reflect that of the primary prostatic adenocarcinoma.

Concordance of biopsy and prostatectomy diagnosis of intraductal and cribriform carcinoma in a prospectively collected data set.

AIMS: Intraductal and cribriform carcinoma of the prostate are increasingly recognised as independent prognosticators of poor outcome, both in prostate biopsies and surgical specimens. We studied the concordance of biopsy and prostatectomy diagnosis for these two subpathologies in relationship with pathological stage. METHODS AND RESULTS: Mandatory synoptic reporting of intraductal and cribriform carcinoma in prostate biopsies and prostatectomy specimens was adopted by two academic institutions in November 2015. Synoptic reports of 245 biopsy and corresponding prostatectomy specimens were interrogated to determine the prevalence of intraductal and cribriform carcinoma. Sensitivity and specificity were determined, with prostatectomy diagnosis as the gold standard. Associations with pathological stage as primary outcome parameter were determined using univariable and multivariable logistic regression analysis. Prevalence of the combination of intraductal and cribriform carcinoma was 26.9% in biopsies and 51.8% in prostatectomy specimens. Sensitivity and specificity at biopsy were 47.2% and 94.9%, respectively. Intraductal and cribriform carcinoma at biopsy were associated with advanced pathological stage independent of grade (P = 0.013). Among patients with grade group 2 prostate cancer at biopsy, the more advanced pathological stage distribution was similar for those with a false negative and a true positive biopsy diagnosis of intraductal and cribriform carcinoma (P = 0.29). CONCLUSION: In spite of low sensitivity, intraductal and cribriform carcinoma at biopsy was associated strongly with advanced stage at radical prostatectomy. As a false negative biopsy diagnosis was equally associated with advanced pathological stage, efforts should be undertaken to improve the sensitivity of biopsy diagnosis for intraductal and cribriform carcinoma.

Basal-subtype bladder tumours show a 'hot' immunophenotype.

AIMS: Basal and luminal molecular subgroups of muscle-invasive urothelial carcinoma (UC) can be recognised by the use of immunohistochemical markers. Studies have shown that responses to chemotherapy and outcomes differ among these subtypes. High-grade UC of the bladder is an immunogenic neoplasm that induces a substantial intratumoral and peritumoral immune response; the phenotype of infiltrating immune cells may yield prognostic information and predict response to therapy. In this study, we aimed to correlate the immunohistochemical phenotype of high-grade UC with immune microenvironment composition. METHODS AND RESULTS: Two hundred and thirty-five cases of high-grade UC treated with cystectomy were reviewed. Clinicopathological variables for each case were recorded, and disease-free survival at last follow-up was calculated. Invasive front inflammation and tumour-infiltrating lymphocytes were scored for each case. Two hundred and seven cases were used to construct a triplicate-core tissue microarray (TMA), with sections stained for cytokeratin (CK) 5/6 and GATA3. Of the evaluable cases, 167 were designated as luminal (CK5/6- and GATA3+) and 29 as basal (CK5/6+ and GATA3-). Additional sequential TMA sections were stained for CD3, CD4, CD8, CD20, CD68, CD163, FOXP3, programmed cell death protein 1 (PD-1), and programmed death-ligand 1 (PD-L1) (SP263). Basal-subtype tumours showed a trend towards worse disease-specific survival (P = 0.078). There were statistically significant associations between basal subtype and CD8 expression (P = 0.008), PD-1 expression (P = 0.001), and PD-L1 expression (P = 0.014). Lower CD4/CD8 and increased CD8/FOXP3 ratios (P = 0.047 and P = 0.031, respectively) were also identified in the basal-subtype group. CONCLUSIONS: Basal-subtype high-grade UC has an abundance of CD8+ T cells with increased expression of inhibitory markers, indicative of a 'hot' immunophenotype.

Prognostic pathological factors in radical cystectomy after neoadjuvant chemotherapy.

AIMS: We undertook a systematic evaluation of the prognostic value of numerous histological factors in 165 radical cystectomies (RCs) of patients with invasive urothelial carcinoma (UC) who underwent surgery after neoadjuvant chemotherapy (NAC). METHODS AND RESULTS: Tumour regression grade (TRG) and therapy-related stromal and epithelial changes were also recorded. Locally advanced disease (≥pT2 and/or pN+) was present in 64% of patients, 22% had no evidence of residual carcinoma (pT0 + pN0), and 28% had no evidence of residual muscle-invasive carcinoma (≤pT1 + N0). TRG1, TRG2 and TRG3 were found in 32%, 15% and 50% of patients, respectively. Histological variants of UC were reported in 25% of cases. The most common therapy-related stromal change was fibroblastic reaction (78%), and the most common epithelial change in residual UC was smudgy and poorly preserved chromatin (28%). Prominent stromal and epithelial changes were noted in 41% and 5% of RCs, respectively. Progression was found in 45% of patients, and cancer-related deaths occurred in 30%. Multivariate analysis showed that the only independent prognostic parameters for progression were T stage, N stage, lymphovascular invasion, and margin status. Similarly, only T stage, N stage and margin status correlated with cancer-related deaths. Neither TRG nor any of the stromal-related or epithelial-related variables correlated with outcome. CONCLUSIONS: We confirm that the traditional and routinely reported histological parameters in RC post-NAC remain the most powerful prognosticators of disease course. The significance of TRG in the bladder remains unconfirmed.

p53 immunohistochemistry in high-grade urothelial carcinoma of the bladder is prognostically significant.

AIMS: TP53 mutations are characteristic of the high-grade pathway in the dual pathway of urothelial carcinogenesis. These mutations have been correlated with aberrant accumulation of p53 protein; however the definition and significance of this vary in the literature. The aim of this study was to assess p53 immunostaining in a cohort of high-grade urothelial carcinomas by using standard published cut-offs and a novel binarized method that included assessment of the null phenotype. Each scoring method was correlated with oncological outcome. METHODS AND RESULTS: A triplicate core tissue microarray was constructed from 207 cases of high-grade urothelial carcinoma treated by cystectomy, and was stained with p53. The percentage nuclear staining was recorded for each core and averaged for every case (206 cases were evaluable). Cases were categorized as positive/negative according to published cut-offs (10%, 40%) or by binarizing them as abnormal (null phenotype or >50% positivity) and wild type (1-49% positivity). Correlation with disease-specific survival was not significant according to standard definitions of p53 positivity. When a 40% cut-off was used, a correlation with relapse-free survival was significant on univariate analysis (P = 0.038) but not on multivariate analysis (P = 0.079). Abnormal p53 expression showed a near-significant trend for association with disease-specific survival (P = 0.052) and was a significant predictor for relapse-free survival on both univariate analysis (P = 0.047) and multivariate analysis (P = 0.035). CONCLUSIONS: Prior to this study, the p53 null phenotype was not well described in urothelial carcinoma of the bladder. Abnormal p53 immunoexpression (null staining pattern or staining in >50% of cells) is prognostic in terms of oncological outcome.

Analysis of papillary urothelial carcinomas of the bladder with grade heterogeneity: supportive evidence for an early role of CDKN2A deletions in the FGFR3 pathway.

AIMS: The dual pathway model of urothelial carcinogenesis does not fully explain grade and stage progression in patients with initial low-grade, non-muscle invasive urothelial carcinomas. Fibroblast growth factor receptor 3 (FGFR3) mutations are a hallmark of the low-grade pathway, with subsequent progression to muscle invasion occurring when FGFR3 mutant tumours exhibit a homozygous CDKN2A deletion. We hypothesized that grade heterogeneity represents the morphological manifestation of molecular changes associated with disease progression. METHODS AND RESULTS: We identified retrospectively 29 non-muscle invasive papillary urothelial carcinomas with grade heterogeneity (<20% high grade). Nineteen had sufficient material for immunohistochemistry, CDKN2A fluorescence in-situ hybridization and FGFR3 mutation analysis. Eight pure low-grade urothelial carcinomas (PLGUC) were also analysed. FGFR3 mutation was seen in 10 of 19 cases. A homozygous CDKN2A deletion was identified in the low-grade areas of eight of nine (88%) technically suitable FGFR3 mutant cases (including five pTa cancers), in five of nine FGFR3 wild-type carcinomas and in none of the PLGUC. Increased MIB-1 expression was seen in low-grade areas of 12 of 19, in high-grade areas of 17 of 19 cases with grade heterogeneity and in none of the PLGUC. p53 staining was increased in one of 19 low-grade and seven of 19 high-grade areas. CONCLUSION: Our findings show that grade heterogeneity in urothelial carcinoma is characterized by increased MIB-1 labelling, and particularly in the FGFR3 mutant pathway, with homozygous deletions of CDKN2A in low- and high-grade areas. This would suggest that CDKN2A deletion occurs prior to grade progression and supports the current convention to assign the highest grade to urothelial carcinomas with grade heterogeneity.

Prostate carcinoma with amphicrine features: further refining the spectrum of neuroendocrine differentiation in tumours of primary prostatic origin?

AIMS: The current World Health Organization classification categorises high-grade neuroendocrine (NE) carcinomas of the prostate into small-cell and large-cell types. A distinct form of carcinoma showing synchronous dual exocrine and NE differentiation, termed amphicrine carcinoma, has been described at various other sites, primarily within the gastrointestinal tract. The aim of this study was to investigate the clinicopathological features of a series of metastatic prostate carcinoma (PCa) cases with amphicrine features. METHODS AND RESULTS: Five cases of high-grade PCa showing an amphicrine immunohistochemical phenotype were prospectively collected. The serum prostate-specific antigen (PSA) level at diagnosis ranged from 38 ng/ml to 992 ng/ml (median 200 ng/ml). All five patients had metastatic disease, four at initial presentation. Microscopically, the tumours showed a solid/nested growth pattern composed of cells with amphophilic cytoplasm, vesicular nuclei, and macronucleoli. Morphological features of small-cell or large-cell NE carcinoma were absent. As compared with conventional high-grade PCa, the tumour cells showed a higher level of nuclear pleomorphism, brisk mitotic activity, and a high Ki67 proliferation index (median 50%). All cases showed immunohistochemical positivity for PSA, androgen receptor, and prostate-specific acid phosphatase, combined with diffuse or confluent/non-focal positivity for chromogranin-A and synaptophysin. Two hormone-naive cases showed a clinical response to androgen deprivation therapy. CONCLUSION: This series highlights a previously undefined, clinically aggressive variant of PCa showing dual exocrine and NE differentiation, for which we are proposing the term PCa with amphicrine features. Increased recognition of these tumours may lead to a better understanding of their biology, and ultimately improve their clinical management.

Review of findings in prophylactic gynaecological specimens in Lynch syndrome with literature review and recommendations for grossing.

AIMS: Prophylactic hysterectomy with bilateral salpingo-oophorectomy is being increasingly undertaken in patients with Lynch syndrome (LS). The pathological features in such specimens are not well described and, unlike the SEE-FIM protocol for salpingo-oophorectomy specimens in BRCA1/2 mutation carriers and the gastrectomy grossing protocols for patients with CDH1 (E-cadherin) mutations, guidelines have not been devised for the grossing of prophylactic gynaecological specimens from LS patients. We aimed to review the pathological findings in a series of prophylactic gynaecological specimens from LS patients and develop guidelines for the grossing of these specimens. METHODS AND RESULTS: We reviewed the pathological findings in 25 prophylactic gynaecological specimens from LS patients and audited the grossing protocols in different centres across Ontario, Canada. We found a 32% incidence of endometrial carcinoma or a precursor lesion; the two endometrial cancers identified were low-grade, low-stage endometrioid adenocarcinomas. To address the absence of guidelines for pathological examination, we undertook a literature review of gynaecological malignancies and incidental findings in prophylactic specimens in LS patients. CONCLUSION: We provide recommendations regarding the grossing of such specimens which includes in-toto examination of the lower uterine segment, endometrium, ovaries and fallopian tubes with representative sampling of the cervix.

Aggressive prostatic adenocarcinoma with urothelial-like morphology, with frequent CK7/CK20/HMWK expression and occasional diffuse neuroendocrine features: A clinicopathologic study of 12 cases.

INTRODUCTION: Prostatic adenocarcinoma can occasionally display urothelial carcinoma morphology, which prompts immunohistochemistry (IHC) studies to determine its lineage. Typically, prostate cancer is characterized by the lack of cytokeratin (CK) 7, CK20 and high molecular weight keratin (HMWK) expression, as opposed to bladder cancer. METHODS: We report a series of 12 prostatic adenocarcinoma cases with unusual urothelial-like morphology, diagnosed at two academic institutions in Toronto between 2018 and 2023, and analyzed by immunohistochemistry for prostatic, urothelial, and neuroendocrine marker expression. We collected patient age, androgen deprivation therapy (ADT) status, tumour site, histomorphology, Grade group (GG) and results of genetic testing. RESULTS: The median age of the 12 patients included in this case series was 75.5 years (range 41-85). A history of prostatic cancer was noted in 7/12 (58%) patients. Five of nine (56%) patients had elevated serum PSA level at diagnosis. Six of eleven (55%) patients had prior ADT. Tumour sites were prostate (n = 6), bladder (n = 3), liver metastases (n = 2), and lung metastasis (n = 1). GGs of the primary tumours were GG3 (n = 1) and GG5 (n = 8). The observed urothelial-like morphology was diffuse in ten cases, and focal in two cases. CK7 was strong/diffuse in 8/11 tested cases, and focal weak in one case. CK20, HMWK, p63 and GATA3 were patchy/focal/weak/moderate in 3/6, 4/7, 4/8 and 2/9 cases, respectively. Ten (83%) cases were positive for at least one prostatic marker; eight (67%) cases had loss/weak staining of at least one prostatic marker. AR loss was seen in 2/7 (29%) cases. Seven of ten (70%) cases had diffuse/strong expression of at least one neuroendocrine marker. No trend was evident between prior ADT/AR status and any IHC result. Molecular analyses for DNA damage repair (DDR) genes (n = 6) demonstrated one ATM deletion (bladder). In addition, one TMPRSS2:ERG fusion (lung metastasis) was identified. CONCLUSION: This series comprises high-grade and/or metastatic prostatic adenocarcinoma cases with distinctive urothelial-like morphology and frequent aberrant CK7/CK20/HMWK expression. Their histomorphology, highly suggestive of an urothelial origin, represents a diagnostic pitfall that can lead to considerable management repercussions. The fact that a high proportion of the reported cases had loss/weak expression of at least one of the tested prostatic-specific markers, and occasionally a diffuse positivity for neuroendocrine markers highlights the importance of (1) clinical history and (2) utilization of broad IHC panels to correctly diagnose such unusual prostate cancer cases.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer. Working Group 1: Comparison of Bladder Cancer Grading System Performance.

Grade is a key prognostic factor in determining progression in nonmuscle invasive papillary urothelial carcinomas. The 2 most common grading methods in use worldwide are the World Health Organization (WHO) 2004 and 1973 schemes. The International Society of Urological Pathology (ISUP) organized the 2022 consensus conference in Basel, Switzerland on current issues in bladder cancer and tasked working group 1 to make recommendations for future iterations of bladder cancer grading. For this purpose, the ISUP developed in collaboration with the European Association of Urology a 10-question survey for their memberships to understand the current use of grading schemes by pathologists and urologists and to ascertain the areas of potential improvements. An additional survey was circulated to the ISUP membership for their opinion on interobserver variability in grading, reporting of urine cytology, and challenges encountered in grade assignment. Comprehensive literature reviews were performed on bladder cancer grading prognosis and interobserver variability along with The Paris System for urine cytology. There are notable differences in practice patterns between North American and European pathologists in terms of used grading scheme and diagnosis of papillary urothelial neoplasm of low malignant potential. Areas of common ground include difficulty in grade assignment, a desire to improve grading criteria, and a move towards subclassifying high-grade urothelial carcinomas. The surveys and in-person voting demonstrated a strong preference to refine current grading into a 3-tier scheme with the division of WHO 2004 high grade into clinically relevant categories. More variable opinions were voiced regarding the use of papillary urothelial carcinoma with low malignant potential.

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.

Engineering the future of 3D pathology.

In recent years, technological advances in tissue preparation, high-throughput volumetric microscopy, and computational infrastructure have enabled rapid developments in nondestructive 3D pathology, in which high-resolution histologic datasets are obtained from thick tissue specimens, such as whole biopsies, without the need for physical sectioning onto glass slides. While 3D pathology generates massive datasets that are attractive for automated computational analysis, there is also a desire to use 3D pathology to improve the visual assessment of tissue histology. In this perspective, we discuss and provide examples of potential advantages of 3D pathology for the visual assessment of clinical specimens and the challenges of dealing with large 3D datasets (of individual or multiple specimens) that pathologists have not been trained to interpret. We discuss the need for artificial intelligence triaging algorithms and explainable analysis methods to assist pathologists or other domain experts in the interpretation of these novel, often complex, large datasets.

Addition of Cribriform and Intraductal Carcinoma Presence to Prostate Biopsy Reporting Strengthens Pretreatment Risk Stratification Using CAPRA and NCCN Tools.

BACKGROUND: Pretreatment stratification tools can help in clinical decision making in prostate cancer. To date, none incorporates well-established routinely reported adverse prognostic pathologic features such as intraductal carcinoma of prostate (IDC) or cribriform pattern 4 (CC). OBJECTIVE: To assess the impact of addition of CC and/or IDC on the Cancer of Prostate Risk Assessment (CAPRA) and National Cancer Comprehensive Network (NCCN) tools for predicting biochemical recurrence free survival (BCR-FS) and event-free survival (EFS) across multiple patient cohorts. DESIGN, SETTING, AND PARTICIPANTS: Matched prostate biopsies and radical prostatectomies from institutions in Toronto, Wisconsin and Rotterdam. The presence/absence of CC/IDC was recorded on all biopsies. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Relationship to outcome was assessed using Cox proportional hazard models, ANOVA and Harrell's concordance index. RESULTS AND LIMITATIONS: We included 1326 patients (Toronto- 612, Wisconsin- 542, Rotterdam- 172) with median follow up of 4.2 years (IQR 2.9-6.4 years); 306 (23.1%) had CC/IDC on biopsy with 207 (20.9%) BCR and 154 (11.6%) events (metastases/death). Addition of CC/IDC improved stratification in CAPRA scores 3 to 5 for BCR-FS (c-index increase 0.633-0.658, P < .001) and scores 6-10 for EFS (c-index increase 0.653-0.697, P < .001). For NCCN, all risk groups apart from score 1 to 2 showed improvement in BCR-FS (c-index increase 0.599-0.636, P < 0.001) and EFS prediction (c-index increase 0.648-0.697, P < .001). Sub-analysis of grade group (GG) 2 biopsies showed similar findings. The retrospective nature and inclusion of cases only reported by genitourinary pathologists are study limitations. CONCLUSIONS: The clinical benefit of the addition of CC/IDC to both CAPRA and NCCN pretreatment tools was validated in 3 cohorts, including the subset of biopsy GG2 prostate cancer patients. PATIENT SUMMARY: Including additional pathologic features to existing pretreatment, clinical decision making tools improves the ability to predict prostate cancer recurrence, cancer spread and death of disease.

Prostate cancer reshapes the secreted and extracellular vesicle urinary proteomes.

Urine is a complex biofluid that reflects both overall physiologic state and the state of the genitourinary tissues through which it passes. It contains both secreted proteins and proteins encapsulated in tissue-derived extracellular vesicles (EVs). To understand the population variability and clinical utility of urine, we quantified the secreted and EV proteomes from 190 men, including a subset with prostate cancer. We demonstrate that a simple protocol enriches prostatic proteins in urine. Secreted and EV proteins arise from different subcellular compartments. Urinary EVs are faithful surrogates of tissue proteomes, but secreted proteins in urine or cell line EVs are not. The urinary proteome is longitudinally stable over several years. It can accurately and non-invasively distinguish malignant from benign prostatic lesions and can risk-stratify prostate tumors. This resource quantifies the complexity of the urinary proteome and reveals the synergistic value of secreted and EV proteomes for translational and biomarker studies.

Morphologic Pattern, Frequency, and Spatial Distribution of Lymphovascular Invasion Foci in Radical Prostatectomy Specimens.

Introduction. Lymphovascular invasion (LVI) is an adverse pathological finding in radical prostatectomy (RP) specimens associated with increased risk of metastatic disease. Its variable incidence may be attributed to underreporting. We characterized the location, quantity, and morphology of LVI foci in RP specimens and assessed the relationship between LVI and cribriform and intraductal carcinoma and metastatic risk. Methods. Two pathologists reviewed retrospectively 54 RP specimens reported as positive for LVI. Ambiguous cases were confirmed by immunostaining for ERG, CD31 and D2-40. Results. In 4/54 (7.4%), LVI could not be confirmed. Main mimickers of LVI were retraction artifact and dislodged tumor cells. Based on our review, the most important criteria to distinguish LVI from its mimickers were a corrugated lining of vascular spaces, endothelial nuclei bulging into the lumen, and presence of proteinaceous material. The LVI frequency per case ranged from 1 to 109 (median 7.5). In 47/50 (94%) cases with LVI, the associated carcinoma comprised cribriform pattern and/or intraductal carcinoma. The most common morphology of LVI foci was cribriform, occurring in 43/50 specimens, representing 469/843 (56%) of LVI foci. Most LVI foci were intraprostatic and located at the carcinoma-stroma interface. Particularly the risk of bone metastases during follow-up was independently associated with higher frequency of LVI foci (P = .009). Conclusions. The detailed description of prostatic LVI, and awareness of their predominant location and morphology may help its identification and improve the diagnostic accuracy of LVI in pathology reporting. The clinical impact of LVI quantification in prostate cancer needs validation by further studies.

Redefining and capturing pre-analytic deficiencies in an anatomical pathology laboratory: a quality improvement initiative.

Pre-analytical deficiencies (PADs) are a major source of errors in anatomical pathology, accounting for about 70% of laboratory deficiencies. These can lead to incorrect diagnoses, delayed treatments, and increased healthcare costs. As part of a quality improvement initiative, we retrospectively identified and characterized 237 PADs documented over a 1-year period in a tertiary care academic center. The most common PADs were errors in specimen procurement (56%), handling of samples within the lab (16%), accessioning (10%), incomplete requisitions (9%), and transportation-related issues (7%). Strategies were then devised to mitigate these errors. Categorization of pre- and intra-laboratory PADs was refined into eight categories (collection, requisition, specimen container, transportation, receiving, accessioning, preparation, and communications) in the laboratory information system. Mandatory PAD documentation was implemented for accessioning staff. Post-implementation, prospective analysis identified that the most common PADs were related to surgical requisitions (75%). Among these, missing ordering physician's signature was the most common, accounting for 67.7% of requisition-related PADs and 50.8% of all PADs. Other common PADs included incomplete information of specimens, clinical information, patient information, physician information, source location, collection time, incorrect requisition forms, and illegible handwritten information. This study highlights the importance of identifying and addressing PADs in the anatomical pathology laboratory setting as well as the potential benefits of implementing standardized documentation and quality improvement processes to address these deficiencies.