Small Cell Bladder Cancer: Treatment Patterns for Local Disease and Associated Outcomes. A Retrospective Cohort Study.

BACKGROUND: Small cell bladder cancer (SCBC) is a rare histologic subtype with relative paucity of data regarding treatment response and outcomes. We reviewed 2 databases to compare outcomes in patients with localized SCBC treated with cystectomy versus concurrent chemoradiotherapy (CCRT). We hypothesized that survival would be similar with these therapy approaches. METHODS: We retrospectively reviewed our institutional and SEER-Medicare databases to identify patients with SCBC. Overall survival (OS) was determined from the date of diagnosis to last follow-up/death. For those with nonmetastatic disease, a multivariate Cox analysis was used to compare locoregional therapy with neoadjuvant chemotherapy (NAC) + cystectomy versus CCRT. RESULTS: We identified 53 patients in our institutional database and 1166 patients in SEER-Medicare with localized SCBC. Median OS (mOS) with NAC + cystectomy was 46 months (95% CI, 21-72) and 45 months (95% CI, 0-104) in the institutional and SEER-Medicare databases, respectively, whereas mOS with CCRT was 26 months (95% CI, 5-47) and 23 months (95% CI, 18-28) in the 2 series, respectively. In multivariate analysis, NAC followed by cystectomy was associated with an approximately 30% reduction in mortality compared to CCRT in both institutional and national databases but did not reach statistical significance (Institution HR 0.71, 95% CI, 0.22-2.4, P = .58; SEER HR 0.73, 95% CI, 0.49-1.08; P = .11). CONCLUSIONS: SCBC is very aggressive with limited survival observed in our institutional and SEER-Medicare datasets regardless of locoregional therapy used. There is an unmet need to define the optimal locoregional therapy for nonmetastatic stage and identify novel therapeutic targets.

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.

Outcome Analysis of a Series of Mixed-Grade, Non-muscle Invasive, Papillary Carcinomas of the Bladder.

Introduction. Papillary urothelial carcinomas are currently graded as either low- or high-grade tumors based on World Health Organization (WHO) 2022 guidelines for genitourinary tumors. However, a minority of tumors are mixed-grade tumors, composed predominantly of low-grade cancer with a minor high-grade component. In the 2022 WHO these cancers are recognized as having outcomes comparable to low-grade cancers, although data to date has been limited. Methods. The pathology records of a large academic institution were searched for mixed-grade, non-muscle invasive papillary carcinomas of the bladder and ureter in order to characterize prognosis of these cancers. Results. Of 136 cancers, the majority (n = 104, 76.5%) were solitary, mixed-grade tumors, while 21 (15.4%) had a concurrent low-grade cancer and 11 (8.1%) had multiple mixed-grade tumors at the time of diagnosis. At follow-up (median 48.3 months, range = 1.3 months-18.1 years), 71 cancers recurred (52.2%): 52 (38.2%) as low- or mixed-grade cancers and 18 (13.2%) as high-grade cancers. There were no instances of stage-progression to >pT2. Conclusions. The clinical outcome of mixed-grade carcinomas was similar to what has been reported for low-grade carcinomas. Based on our results, and prior congruent studies of mixed-grade lesions, these lesions may be regarded as a distinct sub-category with a better prognosis than high-grade tumors.

Enhancing upper tract urothelial carcinoma diagnosis: Utility of cytokeratin 17 and CK20/CD44/p53 immunohistochemical panel.

Upper tract urothelial carcinoma (UTUC) presents diagnostic challenges due to small biopsy specimen size, poor orientation, and technical obstacles that can yield equivocal diagnoses. This uncertainty often mandates repeated biopsies to evaluate the necessity of nephroureterectomy. Prior studies have suggested cytokeratin 17 (CK17) immunostain as an adjunctive tool for diagnosing bladder urothelial neoplasia in both urine cytology and tissue biopsy specimens. We evaluated the utility of CK17 in differentiating UTUC from benign urothelium and its ability to stratify low-grade from high-grade neoplasia. Our study involved a cohort of previously diagnosed cytology (n = 29) and tissue specimens from biopsies and resections (n = 85). We evaluated CK17 staining percentage in cytology and tissue samples and localization patterns in biopsy/resection samples. Our findings showed a statistically significant distinction (p < 0.05) between UTUC and benign tissue specimens based on full thickness localization pattern (odds ratio 8.8 [95% CI 1.53-67.4]). The percentage of CK17 staining failed to significantly differentiate neoplastic from non-neoplastic cases in cytology or tissue samples. Additionally, based on prior research showing the efficacy of CK20/CD44/p53 triple panel in bladder urothelial neoplasia, we utilized tissue microarrays to evaluate if these markers could distinguish UTUC from benign urothelium. We found that CK20/CD44/p53, individually or in combination, could not distinguish urothelial neoplasia from non-neoplasia. Full thickness CK17 urothelial localization by immunohistochemistry was highly reproducible with excellent interobserver agreement and may play a supplementary role in distinguishing upper tract urothelial neoplasia from benign urothelium.

High expression of Trop2 is associated with aggressive localized prostate cancer and is a candidate urinary biomarker.

Distinguishing indolent from clinically significant localized prostate cancer is a major clinical challenge and influences clinical decision-making between treatment and active surveillance. The development of novel predictive biomarkers will help with risk stratification, and clinical decision-making, leading to a decrease in over or under-treatment of patients with prostate cancer. Here, we report that Trop2 is a prognostic tissue biomarker for clinically significant prostate cancer by utilizing the Canary Prostate Cancer Tissue Microarray (CPCTA) cohort composed of over 1100 patients from a multi-institutional study. We demonstrate that elevated Trop2 expression is correlated with worse clinical features including Gleason score, age, and pre-operative PSA levels. More importantly, we demonstrate that elevated Trop2 expression at radical prostatectomy predicts worse overall survival in men undergoing radical prostatectomy. Additionally, we detect shed Trop2 in urine from men with clinically significant prostate cancer. Our study identifies Trop2 as a novel tissue prognostic biomarker and a candidate non-invasive marker for prostate cancer.

Characterization of HOXB13 expression patterns in localized and metastatic castration-resistant prostate cancer.

HOXB13 is a key lineage homeobox transcription factor that plays a critical role in the differentiation of the prostate gland. Several studies have suggested that HOXB13 alterations may be involved in prostate cancer development and progression. Despite its potential biological relevance, little is known about the expression of HOXB13 across the disease spectrum of prostate cancer. To this end, we validated a HOXB13 antibody using genetic controls and investigated HOXB13 protein expression in murine and human developing prostates, localized prostate cancers, and metastatic castration-resistant prostate cancers. We observed that HOXB13 expression increases during later stages of murine prostate development. All localized prostate cancers showed HOXB13 protein expression. Interestingly, lower HOXB13 expression levels were observed in higher-grade tumors, although no significant association between HOXB13 expression and recurrence or disease-specific survival was found. In advanced metastatic prostate cancers, HOXB13 expression was retained in the majority of tumors. While we observed lower levels of HOXB13 protein and mRNA levels in tumors with evidence of lineage plasticity, 84% of androgen receptor-negative castration-resistant prostate cancers and neuroendocrine prostate cancers (NEPCs) retained detectable levels of HOXB13. Notably, the reduced expression observed in NEPCs was associated with a gain of HOXB13 gene body CpG methylation. In comparison to the commonly used prostate lineage marker NKX3.1, HOXB13 showed greater sensitivity in detecting advanced metastatic prostate cancers. Additionally, in a cohort of 837 patients, 383 with prostatic and 454 with non-prostatic tumors, we found that HOXB13 immunohistochemistry had a 97% sensitivity and 99% specificity for prostatic origin. Taken together, our studies provide valuable insight into the expression pattern of HOXB13 during prostate development and cancer progression. Furthermore, our findings support the utility of HOXB13 as a diagnostic biomarker for prostate cancer, particularly to confirm the prostatic origin of advanced metastatic castration-resistant tumors. © 2023 The Pathological Society of Great Britain and Ireland.

Artificial Intelligence-Based PTEN Loss Assessment as an Early Predictor of Prostate Cancer Metastasis After Surgery: A Multicenter Retrospective Study.

Phosphatase and tensin homolog (PTEN) loss is associated with adverse outcomes in prostate cancer and can be measured via immunohistochemistry. The purpose of the study was to establish the clinical application of an in-house developed artificial intelligence (AI) image analysis workflow for automated detection of PTEN loss on digital images for identifying patients at risk of early recurrence and metastasis. Postsurgical tissue microarray sections from the Canary Foundation (n = 1264) stained with anti-PTEN antibody were evaluated independently by pathologist conventional visual scoring (cPTEN) and an automated AI-based image analysis pipeline (AI-PTEN). The relationship of PTEN evaluation methods with cancer recurrence and metastasis was analyzed using multivariable Cox proportional hazard and decision curve models. Both cPTEN scoring by the pathologist and quantification of PTEN loss by AI (high-risk AI-qPTEN) were significantly associated with shorter metastasis-free survival (MFS) in univariable analysis (cPTEN hazard ratio [HR], 1.54; CI, 1.07-2.21; P = .019; AI-qPTEN HR, 2.55; CI, 1.83-3.56; P < .001). In multivariable analyses, AI-qPTEN showed a statistically significant association with shorter MFS (HR, 2.17; CI, 1.49-3.17; P < .001) and recurrence-free survival (HR, 1.36; CI, 1.06-1.75; P = .016) when adjusting for relevant postsurgical clinical nomogram (Cancer of the Prostate Risk Assessment [CAPRA] postsurgical score [CAPRA-S]), whereas cPTEN does not show a statistically significant association (HR, 1.33; CI, 0.89-2; P = .2 and HR, 1.26; CI, 0.99-1.62; P = .063, respectively) when adjusting for CAPRA-S risk stratification. More importantly, AI-qPTEN was associated with shorter MFS in patients with favorable pathological stage and negative surgical margins (HR, 2.72; CI, 1.46-5.06; P = .002). Workflow also demonstrated enhanced clinical utility in decision curve analysis, more accurately identifying men who might benefit from adjuvant therapy postsurgery. This study demonstrates the clinical value of an affordable and fully automated AI-powered PTEN assessment for evaluating the risk of developing metastasis or disease recurrence after radical prostatectomy. Adding the AI-qPTEN assessment workflow to clinical variables may affect postoperative surveillance or management options, particularly in low-risk patients.

Metastatic Bladder Cancer Expression and Subcellular Localization of Nectin-4 and Trop-2 in Variant Histology: A Rapid Autopsy Study.

BACKGROUND: Nectin-4 and Trop-2 are transmembrane targets of FDA-approved antibody-drug conjugates (ADC) Enfortumab-vedotin (EV) and Sacituzumab govitecan (SG), respectively, for the treatment of metastatic urothelial carcinoma (mUC). The expression and role of Nectin-4 and Trop-2 in mUC variant histology is poorly described. MATERIALS AND METHODS: We evaluate membranous and cytoplasmic protein expression, and mRNA levels of Nectin-4 and Trop-2 within matched primary and metastatic mUC samples to determine heterogeneity of ADC targets in mUC variants. RESULTS: Patients with mUC were consented for rapid autopsy immediately after death. Tissues from matched primary and metastatic lesions were collected. A total of 67 specimens from 20 patients were analyzed: 27 were UC, 17 plasmacytoid (PUC), 18 UC with squamous differentiation (UCSD), and 5 neuroendocrine (NE); 10 from primary and 57 from metastatic sites. All histology except NE expressed moderate-high levels of Nectin-4 and Trop-2 by both immunohistochemistry and RNAseq. Nectin-4 demonstrated prominent cytoplasmic staining in metastatic PUC and UCSD. Trop-2 demonstrated strong cytoplasmic and membrane staining in primary and metastatic tumors. Interestingly, Nectin-4 and Trop-2 expression are positively correlated at both mRNA and protein levels. CONCLUSION: UC and non-NE variants express notable level of Nectin-4 and Trop-2 in both primary and metastatic lesions. Membrane staining of Nectin-4 and Trop-2 is present but cytoplasmic staining is a more common event in both mUC and mUC variant histology. These findings support evaluation of EV and SG in heavily treated variant histology BC and urge attention on the clinical relevance of cytoplasmic localization of ADC targets.

Sarcomatoid Urothelial Carcinoma Is Associated With Limited Response to Neoadjuvant Chemotherapy and Poor Oncologic Outcomes After Radical Cystectomy.

INTRODUCTION: To examine oncologic outcomes and response to neoadjuvant chemotherapy (NAC) in patients with sarcomatoid urothelial carcinoma (SUC) treated with radical cystectomy (RC). MATERIALS AND METHODS: We retrospectively queried our institutional database (2003-18) and Surveillance, Epidemiology, and End Results (SEER)-Medicare (2004-2015) for patients with cT2-4, N0-2, M0 SUC and conventional UC (CUC) treated with RC. Clinicopathologic characteristics were described using descriptive statistics (t test, χ2-test and log-rank-test for group comparison). Overall (OS) and recurrence-free-survival (RFS) after RC were estimated with the Kaplan Meier method and associations with OS were evaluated with Cox proportional hazards models. RESULTS: We identified 38 patients with SUC and 287 patients with CUC in our database, and 190 patients with SUC in SEER-Medicare. In the institutional cohort, patients with SUC versus CUC had higher rates of pT3/4 stage (66% vs. 35%, P < 0.001), lower rates of ypT0N0 (6% vs. 35%, P = .02), and worse median OS (17.5 vs. 120 months, P < .001). Further, patients with SUC in the institutional versus SEER-Medicare cohort had similar median OS (17.5 vs. 21 months). In both cohorts, OS was comparable between patients with SUC undergoing NAC+RC vs. RC alone (17.5 vs. 18.4 months, P = .98, institutional cohort; 24 vs. 20 months, P = .56, SEER cohort). In Cox proportional hazards models for the institutional RC cohort, SUC was independently associated with worse OS (HR 2.3, CI 1.4-3.8, P = .001). CONCLUSION: SUC demonstrates poor pathologic response to NAC and worse OS compared with CUC, with no OS benefit associated with NAC. A unique pattern of rapid abdominopelvic cystic recurrence was identified.

Transcriptional-translational conflict is a barrier to cellular transformation and cancer progression.

We uncover a tumor-suppressive process in urothelium called transcriptional-translational conflict caused by deregulation of the central chromatin remodeling component ARID1A. Loss of Arid1a triggers an increase in a nexus of pro-proliferation transcripts, but a simultaneous inhibition of the eukaryotic elongation factor 2 (eEF2), which results in tumor suppression. Resolution of this conflict through enhancing translation elongation speed enables the efficient and precise synthesis of a network of poised mRNAs resulting in uncontrolled proliferation, clonogenic growth, and bladder cancer progression. We observe a similar phenomenon in patients with ARID1A-low tumors, which also exhibit increased translation elongation activity through eEF2. These findings have important clinical implications because ARID1A-deficient, but not ARID1A-proficient, tumors are sensitive to pharmacologic inhibition of protein synthesis. These discoveries reveal an oncogenic stress created by transcriptional-translational conflict and provide a unified gene expression model that unveils the importance of the crosstalk between transcription and translation in promoting cancer.

A Phase 1/2 Study of Rapamycin and Cisplatin/Gemcitabine for Treatment of Patients With Muscle-Invasive Bladder Cancer.

INTRODUCTION: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by cystectomy is the standard for muscle-invasive bladder cancer (MIBC), however, NAC confers only a small survival benefit and new strategies are needed to increase its efficacy. Pre-clinical data suggest that in response to DNA damage the tumor microenvironment (TME) adopts a paracrine secretory phenotype dependent on mTOR signaling which may provide an escape mechanism for tumor resistance, thus offering an opportunity to increase NAC effectiveness with mTOR blockade. PATIENTS & METHODS: We conducted a phase I/II clinical trial to assess the safety and efficacy of gemcitabine-cisplatin-rapamycin combination. Grapefruit juice was administered to enhance rapamycin pharmacokinetics by inhibiting intestinal enzymatic degradation. Phase I was a dose determination/safety study followed by a single arm Phase II study of NAC prior to radical cystectomy evaluating pathologic response with a 26% pCR rate target. RESULTS: In phase I, 6 patients enrolled, and the phase 2 dose of 35 mg rapamycin established. Fifteen patients enrolled in phase II; 13 were evaluable. Rapamycin was tolerated without serious adverse events. At the preplanned analysis, the complete response rate (23%) did not meet the prespecified level for continuing and the study was stopped due to futility. With immunohistochemistry, successful suppression of the mTOR signaling pathway in the tumor was achieved while limited mTOR activity was seen in the TME. CONCLUSION: Adding rapamycin to gemcitabine-cisplatin therapy for patients with MIBC was well tolerated but failed to improve therapeutic efficacy despite evidence of mTOR blockade in tumor cells. Further efforts to understand the role of the tumor microenvironment in chemotherapy resistance is needed.

Analysis of separate training and validation radical prostatectomy cohorts identifies 0.25 mm diameter as an optimal definition for "large" cribriform prostatic adenocarcinoma.

Cribriform growth pattern is well-established as an adverse pathologic feature in prostate cancer. The literature suggests "large" cribriform glands associate with aggressive behavior; however, published studies use varying definitions for "large". We aimed to identify an outcome-based quantitative cut-off for "large" vs "small" cribriform glands. We conducted an initial training phase using the tissue microarray based Canary retrospective radical prostatectomy cohort. Of 1287 patients analyzed, cribriform growth was observed in 307 (24%). Using Kaplan-Meier estimates of recurrence-free survival curves (RFS) that were stratified by cribriform gland size, we identified 0.25 mm as the optimal cutoff to identify more aggressive disease. In univariable and multivariable Cox proportional hazard analyses, size >0.25 mm was a significant predictor of worse RFS compared to patients with cribriform glands ≤0.25 mm, independent of pre-operative PSA, grade, stage and margin status (p < 0.001). In addition, two different subset analyses of low-intermediate risk cases (cases with Gleason score ≤ 3 + 4 = 7; and cases with Gleason score = 3 + 4 = 7/4 + 3 = 7) likewise demonstrated patients with largest cribriform diameter >0.25 mm had a significantly lower RFS relative to patients with cribriform glands ≤0.25 mm (each subset p = 0.004). Furthermore, there was no significant difference in outcomes between patients with cribriform glands ≤ 0.25 mm and patients without cribriform glands. The >0.25 mm cut-off was validated as statistically significant in a separate 419 patient, completely embedded whole-section radical prostatectomy cohort by biochemical recurrence, metastasis-free survival, and disease specific death, even when cases with admixed Gleason pattern 5 carcinoma were excluded. In summary, our findings support reporting cribriform gland size and identify 0.25 mm as an optimal outcome-based quantitative measure for defining "large" cribriform glands. Moreover, cribriform glands >0.25 mm are associated with potential for metastatic disease independent of Gleason pattern 5 adenocarcinoma.

Patterns and timing of perioperative blood transfusion and association with outcomes after radical cystectomy.

BACKGROUND: Perioperative blood transfusion (PBT) has been associated with worse outcomes across tumor types, including bladder cancer. We report our institutional experience with PBT utilization in the setting of radical cystectomy (RC) for patients with bladder cancer, exploring whether timing of PBT receipt influences perioperative and oncologic outcomes. METHODS: Consecutive patients with bladder cancer treated with RC were identified. PBT was defined as red blood cell transfusion during RC or the postoperative admission. Clinicopathologic and peri and/or postoperative parameters were extracted and compared between patients who did and did not receive PBT using Mann Whitney U Test, chi-square, and log-rank test. Overall (OS) and recurrence-free survival (RFS) were estimated with the Kaplan Meier method. Univariate/multivariate logistic and Cox proportional hazards regression were used to identify variables associated with postoperative and oncologic outcomes, respectively. RESULTS: The cohort consisted of 747 patients (77% men; median age 67 years). Median follow-up was 61.5 months (95% CI 55.8-67.2) At least one postoperative complication (90-day morbidity) occurred in 394 (53%) patients. Median OS and RFS were 91.8 months (95% CI: 76.0-107.6) and 66.0 months (95% CI: 48.3-83.7), respectively. On multivariate analysis, intraoperative, but not postoperative, BT was independently associated with shorter OS (HR: 1.74, 95% CI: 1.32-2.29) and RFS (HR: 1.55, 95%CI: 1.20-2.01), after adjusting for relevant clinicopathologic variables. PBT (intra- or post- operative) was significantly associated with prolonged postoperative hospitalization ≥10 days. CONCLUSIONS: Intraoperative BT was associated with inferior OS and RFS, and PBT overall was associated with prolonged hospitalization following RC. Further studies are needed to validate this finding and explore potential causes for this observation.

A bladder cancer patient-derived xenograft displays aggressive growth dynamics in vivo and in organoid culture.

Bladder cancer is among the most prevalent cancers worldwide. Currently, few bladder cancer models have undergone thorough characterization to assess their fidelity to patient tumors, especially upon propagation in the laboratory. Here, we establish and molecularly characterize CoCaB 1, an aggressive cisplatin-resistant muscle-invasive bladder cancer patient-derived xenograft (PDX) and companion organoid system. CoCaB 1 was a subcutaneous PDX model reliably transplanted in vivo and demonstrated an acceleration in growth upon serial transplantation, which was reflected in organoid and 2D cell culture systems. Transcriptome analysis revealed progression towards an increasingly proliferative and stem-like expression profile. Gene expression differences between organoid and PDX models reflected expected differences in cellular composition, with organoids enriched in lipid biosynthesis and metabolism genes and deprived of extracellular components observed in PDXs. Both PDX and organoid models maintained the histological fidelity and mutational heterogeneity of their parental tumor. This study establishes the CoCaB 1 PDX and organoid system as companion representative tumor models for the development of novel bladder cancer therapies.

Diagnostic approach in TFE3-rearranged renal cell carcinoma: a multi-institutional international survey.

Transcription factor E3-rearranged renal cell carcinoma (TFE3-RCC) has heterogenous morphologic and immunohistochemical (IHC) features.131 pathologists with genitourinary expertise were invited in an online survey containing 23 questions assessing their experience on TFE3-RCC diagnostic work-up.Fifty (38%) participants completed the survey. 46 of 50 participants reported multiple patterns, most commonly papillary pattern (almost always 9/46, 19.5%; frequently 29/46, 63%). Large epithelioid cells with abundant cytoplasm were the most encountered cytologic feature, with either clear (almost always 10/50, 20%; frequently 34/50, 68%) or eosinophilic (almost always 4/49, 8%; frequently 28/49, 57%) cytology. Strong (3+) or diffuse (>75% of tumour cells) nuclear TFE3 IHC expression was considered diagnostic by 13/46 (28%) and 12/47 (26%) participants, respectively. Main TFE3 IHC issues were the low specificity (16/42, 38%), unreliable staining performance (15/42, 36%) and background staining (12/42, 29%). Most preferred IHC assays other than TFE3, cathepsin K and pancytokeratin were melan A (44/50, 88%), HMB45 (43/50, 86%), carbonic anhydrase IX (41/50, 82%) and CK7 (32/50, 64%). Cut-off for positive TFE3 fluorescent in situ hybridisation (FISH) was preferably 10% (9/50, 18%), although significant variation in cut-off values was present. 23/48 (48%) participants required TFE3 FISH testing to confirm TFE3-RCC regardless of the histomorphologic and IHC assessment. 28/50 (56%) participants would request additional molecular studies other than FISH assay in selected cases, whereas 3/50 participants use additional molecular cases in all cases when TFE3-RCC is in the differential.Optimal diagnostic approach on TFE3-RCC is impacted by IHC and/or FISH assay preferences as well as their conflicting interpretation methods.

Response to Neoadjuvant Chemotherapy and Survival in Micropapillary Urothelial Carcinoma: Data From a Tertiary Referral Center and the Surveillance, Epidemiology, and End Results (SEER) Program.

BACKGROUND: Micropapillary urothelial carcinoma (MPC) is a rare urothelial carcinoma variant with conflicting data guiding clinical practice. In this study, we explored oncologic outcomes in relation to neoadjuvant chemotherapy (NAC) in a retrospective cohort of patients with MPC, alongside data from Surveillance, Epidemiology, and End Results (SEER)-Medicare. PATIENTS AND METHODS: We retrospectively identified patients with MPC or conventional urothelial carcinoma (CUC) without any variant histology undergoing radical cystectomy (RC) in our institution (2003-2018). SEER-Medicare was also queried to identify patients diagnosed with MPC (2004-2015). Clinicopathologic data and treatment modalities were extracted. Overall survival (OS) was estimated with the Kaplan-Meier method. Mann-Whitney-Wilcoxon and chi-square tests were used for comparative analysis and Cox regression for identifying clinical covariates associated with OS. RESULTS: Our institutional database yielded 46 patients with MPC and 457 with CUC. In SEER-Medicare, 183 patients with MPC were identified, and 63 (34%) underwent RC. In the institutional cohort, patients with MPC had significantly higher incidence of cN+ (17% vs. 8%), pN+ stage (30% vs. 17%), carcinoma-in-situ (43% vs. 25%), and lymphovascular invasion (30% vs. 16%) at RC versus those with CUC (all P < .05). Pathologic complete response (ypT0N0) to NAC was 33% for MPC and 35% for CUC (P = .899). Median OS was lower for institutional MPC versus CUC in univariate analysis (43.6 vs. 105.3 months, P = .006); however, MPC was not independently associated with OS in the multivariate model. Median OS was 25 months in the SEER MPC cohort for patients undergoing RC, while NAC was not associated with improved OS in that group. CONCLUSION: Pathologic response to NAC was not significantly different between MPC and CUC, while MPC histology was not an independent predictor of OS. Further studies are needed to better understand biological mechanisms behind its aggressive features as well as the role of NAC in this histology variant.

Diagnosing 12 prostate needle cores within an hour of biopsy via open-top light-sheet microscopy.

SIGNIFICANCE: Processing and diagnosing a set of 12 prostate biopsies using conventional histology methods typically take at least one day. A rapid and accurate process performed while the patient is still on-site could significantly improve the patient's quality of life. AIM: We develop and assess the feasibility of a one-hour-to-diagnosis (1Hr2Dx) method for processing and providing a preliminary diagnosis of a set of 12 prostate biopsies. APPROACH: We developed a fluorescence staining, optical clearing, and 3D open-top light-sheet microscopy workflow to enable 12 prostate needle core biopsies to be processed and diagnosed within an hour of receipt. We analyzed 44 biopsies by the 1Hr2Dx method, which does not consume tissue. The biopsies were then processed for routine, slide-based 2D histology. Three pathologists independently evaluated the 3D 1Hr2Dx and 2D slide-based datasets in a blinded, randomized fashion. Turnaround times were recorded, and the accuracy of our method was compared with gold-standard slide-based histology. RESULTS: The average turnaround time for tissue processing, imaging, and diagnosis was 44.5 min. The sensitivity and specificity of 1Hr2Dx in diagnosing cancer were both >90 % . CONCLUSIONS: The 1Hr2Dx method has the potential to improve patient care by providing an accurate preliminary diagnosis within an hour of biopsy.