Diagnostic accuracy of upper tract urothelial carcinoma using biopsy, urinary cytology, and nephroureterectomy specimens: A tertiary cancer center experience.

OBJECTIVES: We studied the diagnostic accuracy and discordance of upper tract urothelial carcinoma (UTUC) by comparing biopsy and urinary cytology with matched nephroureterectomy specimens. METHODS: Sixty-nine patients with UTUC without neoadjuvant treatment were retrospectively identified who had matched biopsy and nephroureterectomy specimens. Twenty patients had concurrent upper tract cytology. H&E and cytology slides were re-reviewed. Statistical analysis was performed. RESULTS: Patients included 48 men and 21 women with a mean age of 69 years. A concordant grade between biopsy and surgical specimen was present in 49 (71%) patients. The mean size of biopsy specimens in the discordant group was significantly smaller than that in the concordant group. Invasion was evaluated in 48 biopsy cases that had adequate subepithelial tissue, and 33 of them were diagnosed with concordant invasion status. Mean tumor size in both tumor grade and invasion discordant groups was significantly larger than that in the concordant group. High-grade urothelial carcinoma was detected in 84% of cases using urinary cytology. CONCLUSIONS: Our study demonstrates the diagnostic challenges of UTUC on small biopsy specimens. Biopsy specimen size and tumor size are significantly associated with the diagnostic discordance. Upper tract cytology showed high diagnostic accuracy and should be complementary to the biopsy.

Plasmacytoid urothelial carcinoma of the urinary bladder-A clinicopathological and molecular analysis of 52 cases.

Plasmacytoid urothelial carcinoma (UC) is a rare histologic subtype of bladder cancer that is associated with an aggressive clinical behavior. We analyzed the clinicopathologic and molecular features of plasmacytoid UC in 52 patients from a single institute. The patients included 44 men and 8 women, with a mean age of 64 years (range, 41-91 years). All bladder cancers were high-grade UC, and plasmacytoid component accounted for a mean of 47% of bladder tumors (range, 5-100%). Distinct gene mutations were found in most plasmacytoid UCs (n = 49); the most common mutations were TP53 (n = 30), followed by TERT (n = 20), and CDH1 (n = 18). Copy number analysis was performed in 34 patients, and 13 of them showed copy number variations. Expression of HER2 was analyzed in 18 patients by immunohistochemistry, and 3 of them showed HER2 overexpression, which was confirmed by fluorescence in situ hybridization analysis. Thirty-two patients died of disease in a median of 15 months (range, 1-45 months). No individual gene mutations were significantly associated with clinical outcome, but mutations in the mammalian target of rapamycin (mTOR) pathway, including PICK3CA and PIK3R1 mutations, were associated with a significantly shorter survival duration (p < 0.05). Plasmacytoid UC is an aggressive histologic subtype that demonstrates frequent somatic gene mutations and CNVs, which may underlie its oncogenesis and progression. Gene mutations of the mTOR pathway are associated with poor outcome in a subset of patients with plasmacytoid UC.

The IL6/JAK/STAT3 signaling axis is a therapeutic vulnerability in SMARCB1-deficient bladder cancer.

SMARCB1 loss has long been observed in many solid tumors. However, there is a need to elucidate targetable pathways driving growth and metastasis in SMARCB1-deficient tumors. Here, we demonstrate that SMARCB1 deficiency, defined as genomic SMARCB1 copy number loss associated with reduced mRNA, drives disease progression in patients with bladder cancer by engaging STAT3. SMARCB1 loss increases the chromatin accessibility of the STAT3 locus in vitro. Orthotopically implanted SMARCB1 knockout (KO) cell lines exhibit increased tumor growth and metastasis. SMARCB1-deficient tumors show an increased IL6/JAK/STAT3 signaling axis in in vivo models and patients. Furthermore, a pSTAT3 selective inhibitor, TTI-101, reduces tumor growth in SMARCB1 KO orthotopic cell line-derived xenografts and a SMARCB1-deficient patient derived xenograft model. We have identified a gene signature generated from SMARCB1 KO tumors that predicts SMARCB1 deficiency in patients. Overall, these findings support the clinical evaluation of STAT3 inhibitors for the treatment of SMARCB1-deficient bladder cancer.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer: Working Group 3: Subcategorization of T1 Bladder Cancer.

Emerging data on T1 bladder cancer subcategorization (aka substaging) suggests a correlation with oncological outcomes. The International Society of Urological Pathology (ISUP) organized the 2022 consensus conference in Basel, Switzerland to focus on current issues in bladder cancer and tasked working group 3 to make recommendations for T1 subcategorization in transurethral bladder resections. For this purpose, the ISUP developed and circulated a survey to their membership querying approaches to T1 bladder cancer subcategorization. In particular, clinical relevance, pathological reporting, and endorsement of T1 subcategorization in the daily practice of pathology were surveyed. Of the respondents of the premeeting survey, about 40% do not routinely report T1 subcategory. We reviewed literature on bladder T1 subcategorization, and screened selected articles for clinical performance and practicality of T1 subcategorization methods. Published literature offered evidence of the clinical rationale for T1 subcategorization and at the conference consensus (83% of conference attendants) was obtained to report routinely T1 subcategorization of transurethral resections. Semiquantitative T1 subcategorization was favored (37%) over histoanatomic methods (4%). This is in line with literature findings on practicality and prognostic impact, that is, a shift of publications from histoanatomic to semiquantitative methods or by reports incorporating both methodologies is apparent over the last decade. However, 59% of participants had no preference for either methodology. They would add a comment in the report briefly stating applied method, interpretation criteria (including cutoff), and potential limitations. When queried on the terminology of T1 subcategorization, 34% and 20% of participants were in favor of T1 (microinvasive) versus T1 (extensive) or T1 (focal) versus T1 (nonfocal), respectively.

Bladder cancer.

Bladder cancer is a global health issue with sex differences in incidence and prognosis. Bladder cancer has distinct molecular subtypes with multiple pathogenic pathways depending on whether the disease is non-muscle invasive or muscle invasive. The mutational burden is higher in muscle-invasive than in non-muscle-invasive disease. Commonly mutated genes include TERT, FGFR3, TP53, PIK3CA, STAG2 and genes involved in chromatin modification. Subtyping of both forms of bladder cancer is likely to change considerably with the advent of single-cell analysis methods. Early detection signifies a better disease prognosis; thus, minimally invasive diagnostic options are needed to improve patient outcomes. Urine-based tests are available for disease diagnosis and surveillance, and analysis of blood-based cell-free DNA is a promising tool for the detection of minimal residual disease and metastatic relapse. Transurethral resection is the cornerstone treatment for non-muscle-invasive bladder cancer and intravesical therapy can further improve oncological outcomes. For muscle-invasive bladder cancer, radical cystectomy with neoadjuvant chemotherapy is the standard of care with evidence supporting trimodality therapy. Immune-checkpoint inhibitors have demonstrated benefit in non-muscle-invasive, muscle-invasive and metastatic bladder cancer. Effective management requires a multidisciplinary approach that considers patient characteristics and molecular disease characteristics.

Comparative Effectiveness Analysis of Treatment Strategies for Surgically Resectable Neuroendocrine Carcinoma of the Urinary Tract.

BACKGROUND: Neoadjuvant chemotherapy (neoCTX) has been recommended as the optimal strategy in surgically resectable neuroendocrine carcinoma (NEC) of the urinary tract (NEC-URO). OBJECTIVE: To determine the systemic therapy regimen and timing, which are most active against NEC-URO. DESIGN, SETTING, AND PARTICIPANTS: We used our institutional historical clinical and pathological database to study 203 patients (cT2, 74%; cT3/4a, 22%; and cTx, 4%) with surgically resectable NEC-URO between November 1985 and May 2020. A total of 141 patients received neoCTX and 62 underwent initial radical surgery, 24 of whom received adjuvant CTX (adjCTX). INTERVENTION: Neoadjuvant CTX with etoposide/cisplatin (EP), an alternating doublet of ifosfamide/doxorubicin (IA) and EP, dose-dense methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), gemcitabine/cisplatin (GC), or others. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Overall survival (OS), downstaging rate, and pathological complete response using a multivariable model adjusting for tumor- and patient-related factors. RESULTS AND LIMITATIONS: Downstaging rate was significantly improved with neoCTX versus initial surgery (49.6% vs 14.5%, p < 0.0001), stage cT2N0 versus cT3/4N0 (44% vs 25%, p = 0.01), or presence of carcinoma in situ (47% vs 28%, p = 0.01). Downstaging was greatest with IA/EP (65%) versus EP (39%), MVAC/GC (27%), or others (36%, p = 0.04). After adjusting for age and Eastern Cooperative Oncology Group performance status, IA/EP was still associated with improved downstaging (odds ratio = 3.7 [1.3-10.2], p = 0.01). At a median follow-up of 59.7 mo, 5-yr OS rates for neoCTX followed by surgery, surgery alone, and surgery followed by adjCTX were 57%, 22%, and 30%, respectively. An NEC regimen (IA/EP or EP) versus a urothelial regimen (MVAC/GC or others) was associated with improved survival (145.4 vs 42.5 mo, hazard ratio = 0.49, 95% confidence interval: 0.25-0.94). CONCLUSIONS: Neoadjuvant CTX remains the standard-of-care treatment for NEC-URO with an advantage for NEC regimens over traditional urothelial regimens. IA/EP improves pathological downstaging at the time of surgery compared with EP, but is reserved for younger and higher function patients. PATIENT SUMMARY: In this report, we looked at the outcomes from invasive neuroendocrine carcinoma of the urinary tract in a large US population. We found that the outcomes varied with treatment strategy. We conclude that the best outcomes are seen in patients treated with chemotherapy prior to surgery and regimens tailored to histology and tolerance.

Assessing the Impact of the COVID-19 Pandemic on Training at the MD Anderson Cancer Center Anatomical Pathology Fellowship Program.

CONTEXT.­: To provide high-quality, safe training during the COVID-19 pandemic, our anatomic pathology fellowship program implemented a hybrid virtual/in-person training model with supplemental digital material. OBJECTIVE.­: To evaluate the impact of this model. DESIGN.­: We examined Accreditation Council for Graduate Medical Education survey results and board pass rates for fellows before the pandemic (group 1); during the pandemic peak (group 2); and early and late after the pandemic peak (groups 3 and 4). Additionally, we distributed an online survey including questions related to performance as attending physicians and fellowship experience to recent graduates. RESULTS.­: Information loss during handover, supervision and teaching by faculty, and having at least 4 free days a month exhibited the greatest score declines between group 1 and groups 2, 3, and 4 on the Accreditation Council for Graduate Medical Education surveys. No differences were seen in board passing rates between groups. The groups did not differ in responses regarding preparation for role as attending, confidence in role as attending, or overall impression of the fellowship program. The pandemic-affected groups responded more positively on the perceived utility of supplemental digital material, impact of digital pathology on quality of education, and impact of supplemental digital material on familiarity with digital pathology. The difference was particularly large between group 1 and combined groups 3 and 4. CONCLUSIONS.­: Despite the limitations noted, the hybrid training model was effective and successfully prepared fellows for their role as attending physicians. Similar studies can be informative for the implementation of similar programs or for the meaningful integration of digital pathology into training curricula.

Emerging Roles for Mammalian Target of Rapamycin (mTOR) Complexes in Bladder Cancer Progression and Therapy.

The mammalian target of rapamycin (mTOR) pathway regulates important cellular functions. Aberrant activation of this pathway, either through upstream activation by growth factors, loss of inhibitory controls, or molecular alterations, can enhance cancer growth and progression. Bladder cancer shows high levels of mTOR activity in approximately 70% of urothelial carcinomas, suggesting a key role for this pathway in this cancer. mTOR signaling initiates through upstream activation of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) and results in activation of either mTOR complex 1 (mTORC1) or mTOR complex 2 (mTORC2). While these complexes share several key protein components, unique differences in their complex composition dramatically alter the function and downstream cellular targets of mTOR activity. While significant work has gone into analysis of molecular alterations of the mTOR pathway in bladder cancer, this has not yielded significant benefit in mTOR-targeted therapy approaches in urothelial carcinoma to date. New discoveries regarding signaling convergence onto mTOR complexes in bladder cancer could yield unique insights the biology and targeting of this aggressive disease. In this review, we highlight the functional significance of mTOR signaling in urothelial carcinoma and its potential impact on future therapy implications.

MRI appearance of BRCA-associated prostate cancer.

Despite advances in diagnosis and treatment, prostate cancer remains the second leading cause of cancer related mortality in men. Prognosis is variable and dependent on several clinical and genetic factors, including BRCA gene mutations. Recent clinical studies have reported that BRCA-associated prostate cancer is a more aggressive subtype with a higher probability of nodal involvement and distant metastases at the time of diagnosis, but radiological findings have not been described. Accurate recognition of those tumors could help guide clinical management and prompt testing and counseling for BRCA mutations. We have recently encountered four patients with BRCA-associated prostate cancer who underwent multiparametric MRI. The MRI appearances of these tumors, which were generally locally advanced and aggressive in appearance, are presented to facilitate recognition of BRCA-associated prostate cancer and guide potential genetic testing and counseling.

Characterization of Cellular and Acellular Analytes from Pre-Cystectomy Liquid Biopsies in Patients Newly Diagnosed with Primary Bladder Cancer.

Urinary bladder cancer (BCa) is the 10th most frequent cancer in the world, most commonly found among the elderly population, and becomes highly lethal once cells have spread from the primary tumor to surrounding tissues and distant organs. Cystectomy, alone or with other treatments, is used to treat most BCa patients, as it offers the best chance of cure. However, even with curative intent, 29% of patients experience relapse of the cancer, 50% of which occur within the first year of surgery. This study aims to use the liquid biopsy to noninvasively detect disease and discover prognostic markers for disease progression. Using the third generation high-definition single cell assay (HDSCA3.0), 50 bladder cancer patient samples and 50 normal donor (ND) samples were analyzed for circulating rare events in the peripheral blood (PB), including circulating tumor cells (CTCs) and large extracellular vesicles (LEVs). Here, we show that (i) CTCs and LEVs are detected in the PB of BCa patients prior to cystectomy, (ii) there is a high heterogeneity of CTCs, and (iii) liquid biopsy analytes correlate with clinical data elements. We observed a significant difference in the incidence of rare cells and LEVs between BCa and ND samples (median of 74.61 cells/mL and 30.91 LEVs/mL vs. 34.46 cells/mL and 3.34 LEVs/mL, respectively). Furthermore, using classification models for the liquid biopsy data, we achieved a sensitivity of 78% and specificity of 92% for the identification of BCa patient samples. Taken together, these data support the clinical utility of the liquid biopsy in detecting BCa, as well as the potential for predicting cancer recurrence and survival post-cystectomy to better inform treatment decisions in BCa care.

Updated pathology reporting standards for bladder cancer: biopsies, transurethral resections and radical cystectomies.

AIM: Optimal management of bladder cancer requires an accurate, standardised and timely pathological diagnosis, and close communication between surgeons and pathologists. Here, we provide an update on pathology reporting standards of transurethral resections of the bladder and cystectomies. METHODS: We reviewed recent literature, focusing on developments between 2013 and 2021. RESULTS: Published reporting standards developed by pathology organizations have improved diagnosis and treatment. Tumor sub-staging and subtyping has gained increased attention. Lymph nodes continue to be an area of debate, and their staging has seen minor modifications. Several tasks, particularly regarding specimen preparation ("grossing"), are not yet standardized and offer opportunity for improvement. Molecular classification is rapidly evolving, but currently has only limited impact on management. CONCLUSION: Pathological reporting of bladder cancer is continuously evolving and remains challenging in some areas. This review provides an overview of recent major developments, with a particular focus on published reporting standards.

Refining neoadjuvant therapy clinical trial design for muscle-invasive bladder cancer before cystectomy: a joint US Food and Drug Administration and Bladder Cancer Advocacy Network workshop.

The success of the use of novel therapies in the treatment of advanced urothelial carcinoma has contributed to growing interest in evaluating these therapies at earlier stages of the disease. However, trials evaluating these therapies in the neoadjuvant setting must have clearly defined study elements and appropriately selected end points to ensure the applicability of the trial and enable interpretation of the study results. To advance the development of rational trial design, a public workshop jointly sponsored by the US Food and Drug Administration and the Bladder Cancer Advocacy Network convened in August 2019. Clinicians, clinical trialists, radiologists, biostatisticians, patients, advocates and other stakeholders discussed key elements and end points when designing trials of neoadjuvant therapy for muscle-invasive bladder cancer (MIBC), identifying opportunities to refine eligibility, design and end points for neoadjuvant trials in MIBC. Although pathological complete response (pCR) is already being used as a co-primary end point, both individual-level and trial-level surrogacy for time-to-event end points, such as event-free survival or overall survival, remain incompletely characterized in MIBC. Additionally, use of pCR is limited by heterogeneity in pathological evaluation and the fact that the magnitude of pCR improvement that might translate into a meaningful clinical benefit remains unclear. Given existing knowledge gaps, capture of highly granular patient-related, tumour-related and treatment-related characteristics in the current generation of neoadjuvant MIBC trials will be critical to informing the design of future trials.

Bladder Cancer Invasion Is Mediated by Mammalian Target of Rapamycin Complex 2-Driven Regulation of Nitric Oxide and Invadopodia Formation.

Bladder cancer invasion depends on mammalian target of rapamycin complex 2 (mTORC2) activity, although the downstream mTORC2 effectors that mediate this effect have not been fully defined. One potential downstream effector is the arginine derivative nitric oxide (NO). This study identified a stage-associated increase in the expression of the NO-generating enzymes endothelial NO synthase (eNOS) and inducible NOS (iNOS) in human bladder cancer. Reduction of NOS activity by pharmacologic inhibition or silencing of NOS enzymes reduced cancer cell invasion, with similar effects observed using the NO scavenger cobinamide. By contrast, enhanced invasion was seen with the NO donor Deta-NONOate and an analog of the downstream NO second messenger cGMP. Next, NOS expression was evaluated in invadopodia, which are cellular protrusions that form the invasive tips of cancer cells. Invadopodia were enriched in both iNOS protein and mTORC2 activity, and invadopodia formation was increased by Deta-NONOate and decreased by cobinamide and ablation of mTORC2 activity. Additionally, mTORC2 increased expression of iNOS. Using a zebrafish model, injection of iNOS- or rictor-silenced cells reduced the frequency of bladder cancer cell metastasis in zebrafish. These results indicate that mTORC2 can mediate bladder cancer cell invasion through increased iNOS expression, resulting in increased NO and cGMP production in invadopodia and further propagation of invadopodia formation.

Comparison of SARS-CoV-2 PCR-Based Detection Using Saliva or Nasopharyngeal Swab Specimens in Asymptomatic Populations.

The coronavirus disease 2019 (COVID-19) pandemic has challenged clinical diagnostic operations due to supply shortages and high staffing needs to collect nasopharyngeal (NP) swab samples. Saliva is an easily accessible alternative specimen type to overcome some of these challenges. In this study, we first used paired saliva and NP swab specimens (n = 128) to compare test performance characteristics with three RNA extraction platforms, i.e., Maxwell RSC (Promega), MagNA Pure 96 (Roche), and KingFisher Flex (Thermo Fisher Scientific), together with two PCR chemistries, i.e., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (2019-nCoV) Centers for Disease Control and Prevention (CDC) quantitative PCR (qPCR) probe assay (Integrated DNA Technologies) and TagPath COVID-19 combination kit (Thermo Fisher Scientific). This study demonstrated that both saliva and NP swab specimens performed well, with 97% agreement when tested by the CDC qPCR chemistry using Maxwell and MagNA Pure RNA extraction platforms. We then compared 12 weeks of saliva and NP swab testing results using two independent asymptomatic populations, including a community surveillance program using saliva samples only (n = 466) and preoperative screening using NP swab samples only (n = 8,461). The positive detection rates among participants with either saliva or NP swab samples were 1.07% and 1.12%, respectively, which confirms the low pretest probabilities for COVID-19 infections in asymptomatic populations. Notably, there was no increased proportion of low-titer cases (inconclusive results) reported in the asymptomatic groups, compared with the all-comers groups (0.21% and 0.66%, respectively, in the community population and 0.25% and 0.49%, respectively, in the preoperative population); this suggests that low-viral-titer carriers can be found similarly in both groups with saliva or NP swab specimens. In summary, saliva can be considered a good alternative for noninvasive but well-instructed self-collection. IMPORTANCE Our study shows that saliva is a noninvasive respiratory secretion sample type that contains equal or more host materials (RNase P), compared with those contained in the corresponding NP swab specimens, in 103 paired samples. SARS-CoV-2 detection with two RNA extraction platforms, Maxwell and MagNA Pure, with CDC qPCR chemistry showed similar test sensitivities for paired specimens. We then analyzed SARS-CoV-2 detections rates in two independent groups of asymptomatic participants, i.e., a group at a community screening station with supervised saliva collection only (n = 466) and a preoperative screening group (n = 8,461) with NP swabbing only. Similar detection rates of 1.07% for the community group and 1.12% for the preoperative group supported the similar test performances in these groups predicted to have low pretest probabilities of infection. With mindful preparation, saliva can be considered for schools and clinical participants when adequate collection education can be provided and compliance can be established.

A 25 year perspective on advances in the pathologic assessment and diagnosis of urologic cancers.

Over the past 25 years, diagnostic categories in genitourinary pathology have changed dramatically. Prostate cancer reporting incorporated numerous new variant categories, recognized the importance of intraductal carcinoma, and introduced the concept of Grade Groups. Pathologic diagnosis of bladder cancer not only added new variant categories, but also modified the grading of non-invasive urothelial neoplasms and refined staging definitions. Kidney cancer classification expanded from a handful of diagnostic categories to a broad array of additional cancer types defined by unique immunohistochemical and molecular findings. Segregation of penile carcinoma by human papillomavirus status more accurately reflected pathogenesis and helped improve prediction of cancer behavior. Testicular pathology research advanced understanding of germ cell tumor subtypes and their impact on patient outcomes. Finally, adrenal gland pathology has evolved to incorporate a broader recognition of morphological variation and risk factors associated with tumor progression. Taken together, changes in pathology over the past quarter century have revolutionized our approach to genitourinary cancers. This review seeks to highlight some of the many significant changes in genitourinary pathology that have occurred during the past 25 years and emphasize impacts on clinical outcomes or therapy, as relevant.

The Genitourinary Pathology Society Update on Classification and Grading of Flat and Papillary Urothelial Neoplasia With New Reporting Recommendations and Approach to Lesions With Mixed and Early Patterns of Neoplasia.

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder neoplasia with a focus on issues relevant to the practicing surgical pathologist for the understanding and effective reporting of bladder cancer, emphasizing particularly on the newly accumulated evidence post-2016 World Health Organization (WHO) classification. The work is presented in 2 manuscripts. Here, in the first, we revisit the nomenclature and classification system used for grading flat and papillary urothelial lesions centering on clinical relevance, and on dilemmas related to application in routine reporting. As patients of noninvasive bladder cancer frequently undergo cystoscopy and biopsy in their typically prolonged clinical course and for surveillance of disease, we discuss morphologies presented in these scenarios which may not have readily applicable diagnostic terms in the WHO classification. The topic of inverted patterns in urothelial neoplasia, particularly when prominent or exclusive, and beyond inverted papilloma has not been addressed formally in the WHO classification. Herein we provide a through review and suggest guidelines for when and how to report such lesions. In promulgating these GUPS recommendations, we aim to provide clarity on the clinical application of these not so uncommon diagnostically challenging situations encountered in routine practice, while also importantly advocating consistent terminology which would inform future work.

The Genitourinary Pathology Society Update on Classification of Variant Histologies, T1 Substaging, Molecular Taxonomy, and Immunotherapy and PD-L1 Testing Implications of Urothelial Cancers.

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder cancer focusing on important topics of high interest for the practicing surgical pathologist and urologist. This review represents the second of 2 manuscripts ensuing from this effort. Herein, we address the effective reporting of bladder cancer, focusing particularly on newly published data since the last 2016 World Health Organization (WHO) classification. In addition, this review focuses on the importance of reporting bladder cancer with divergent differentiation and variant (subtypes of urothelial carcinoma) histologies and the potential impact on patient care. We provide new recommendations for reporting pT1 staging in diagnostic pathology. Furthermore, we explore molecular evolution and classification, emphasizing aspects that impact the understanding of important concepts relevant to reporting and management of patients.

Expression of uroplakin II and GATA-3 in bladder cancer mimickers: caveats in the use of a limited panel to determine cell of origin in bladder lesions.

Antibodies targeting uroplakin II (UPII) are highly specific for urothelial cells and are frequently used to determine if a primary bladder lesion or a metastatic lesion originates from the urothelium. However, to date, no studies have tested the expression of UPII in histological mimickers of bladder cancer that are nonurothelial in origin. Given the potential risk of misdiagnosis, immunohistochemical markers are often used to better characterize these lesions. In the present study, we analyzed the immunohistochemical expression of UPII in a set of urothelial carcinoma mimickers that included conventional nephrogenic adenoma (n = 8), papillary nephrogenic adenoma (n = 6), endometriosis/endosalpingiosis (n = 5), inflammatory myofibroblastic tumor (n = 4), ectopic prostate tissue (n = 2), and malakoplakia (n = 2). We also examined the expression of GATA-3, another commonly used immunohistochemical marker in bladder cancer diagnosis, in the same lesions. Weak immunoreactivity for UPII was identified in 6 of 27 mimickers (22%), and GATA-3 was expressed in 16 of 27 mimickers (59%). Strong immunoreactivity for UPII appeared to be a specific marker for urothelial cell of origin, although weak staining was seen in a significant proportion of mimickers. GATA-3 immunostaining was present in a greater number and broader spectrum of mimickers; however, only one case of papillary nephrogenic adenoma showed dual positivity for UPII and GATA-3. These findings support the immunohistochemical panel-based approach in the diagnosis of bladder lesions, especially if nonurothelial bladder cancer mimickers are in the differential diagnosis. Additional larger studies would be of value to expand on these findings.

Androgen Receptor Regulates CD44 Expression in Bladder Cancer.

The androgen receptor (AR) is important in the development of both experimental and human bladder cancer. However, the role of AR in bladder cancer growth and progression is less clear, with literature indicating that more advanced stage and grade disease are associated with reduced AR expression. To determine the mechanisms underlying these relationships, we profiled AR-expressing human bladder cancer cells by AR chromatin immunoprecipitation sequencing and complementary transcriptomic approaches in response to in vitro stimulation by the synthetic androgen R1881. In vivo functional genomics consisting of pooled shRNA or pooled open reading frame libraries was employed to evaluate 97 genes that recapitulate the direction of expression associated with androgen stimulation. Interestingly, we identified CD44, the receptor for hyaluronic acid, a potent biomarker and driver of progressive disease in multiple tumor types, as significantly associated with androgen stimulation. CRISPR-based mutagenesis of androgen response elements associated with CD44 identified a novel silencer element leading to the direct transcriptional repression of CD44 expression. In human patients with bladder cancer, tumor AR and CD44 mRNA and protein expression were inversely correlated, suggesting a clinically relevant AR-CD44 axis. Collectively, our work describes a novel mechanism partly explaining the inverse relationship between AR and bladder cancer tumor progression and suggests that AR and CD44 expression may be useful for prognostication and therapeutic selection in primary bladder cancer. SIGNIFICANCE: This study describes novel AREs that suppress CD44 and an expected inverse correlation of AR-CD44 expression observed in human bladder tumors.