Histologic grading of urothelial carcinoma: a reappraisal

Cytomorphological characteristics of low-grade papillary urothelial carcinoma in voided urine samples: Distinction from benign and high-grade papillary urothelial carcinoma

OBJECTIVE

Given its frequent recurrence and the potential for high-grade transformation, accurate diagnosis of low-grade papillary urothelial carcinoma (LGPUC) in urine cytology is clinically important. We attempted to identify cytomorphologic features in urine samples, which could be helpful for the identification of LGPUC.

METHODS

We conducted a retrospective review of voided urine specimens collected from patients with histopathologic diagnoses of LGPUC. Their cytomorphological features were compared with those from patients with benign conditions and high-grade papillary urothelial carcinoma (HGPUC).

RESULTS

A total of 115 voided urine specimens were evaluated, including 30 benign, 41 LGPUC, and 44 HGPUC cases. In LGPUC, 18 cases (44%) were diagnosed as atypical, a proportion significantly higher than that observed in benign cases (4 cases, 13%), while the remaining 23 cases (56%) were diagnosed as negative. LGPUC urine samples tended to have higher cellularity than benign cases, but the difference was not statistically significant. Three cytological features, namely nuclear enlargement, higher nuclear-to-cytoplasmic (N/C) ratio, and presence of small cell clusters, were statistically more prevalent in LGPUC compared to benign cases, although the changes were relatively subtle. In contrast, cytomorphological distinction between LGPUC and HGPUC was evident, as high cellularity, nuclear enlargement, hyperchromasia, high N/C ratio, irregular nuclear membrane, and apoptosis were significantly more prevalent in HGPUC cases.

CONCLUSIONS

Several cytomorphologic features in voided urine samples were more prevalent in cases with LGPUC, albeit not observed in all instances. Since these alterations were relatively subtle, meticulous attention to these cytomorphologic details is crucial to suggest the possibility of LGPUC.

Assessment of Tumor-Associated Tissue Eosinophilia (TATE) and Tumor-Associated Macrophages (TAMs) in Canine Transitional Cell Carcinoma of the Urinary Bladder

Transitional cell carcinoma of the urinary bladder is a significant neoplasm in dogs, characterized by a poor prognosis and a high metastatic potential. These canine spontaneous tumors share many characteristics with human transitional cell carcinoma, making them an excellent comparative model. The role of inflammatory infiltration in tumor development and progression is frequently contradictory, especially concerning tumor-associated tissue eosinophils (TATE) and tumor-associated macrophages (TAMs). This study aims to analyze TATE and TAMs in canine transitional cell carcinoma of the urinary bladder. Congo Red staining was used to identify TATE, and immunohistochemistry was performed to detect TAMs in 34 cases of canine transitional cell carcinoma of the bladder carcinomas, categorized into low and high grades. Statistically significant differences were observed between the number of eosinophils and macrophages in the two groups of tumors. The number of TATE was higher in low-grade malignant tumors, but the number of TAMs was higher in high-grade tumors. Our findings suggest the importance of TATEs and TAMs in the aggressiveness of canine transitional cell carcinoma and propose their potential use as therapeutic targets.

Head-to-head: how many categories for grading urothelial carcinoma?

Tumour grade is a critical prognostic parameter for guiding the management of patients with non-muscle invasive bladder cancer. In 2004, the World Health Organisation (WHO) adopted a binary (low-grade/high-grade) grading system to replace the three-tier (grades 1-3) system used to grade urothelial carcinoma since 1973. However, there is significant global variation in the grading of urothelial carcinoma. Some pathology and clinical guidelines recommend reporting of the WHO 1973 and 2004 grades in parallel, while others require reporting only of the WHO 2004 grade. This variation in pathology practice is clinically significant, because the two grading systems are not readily translatable. Some experts have proposed novel systems for grading urothelial carcinoma that involve splitting of the WHO 1973 and 2004 grade categories. The arguments for and against splitting urothelial carcinomas into two-, three- and four-grade categories are independently discussed by the three authors.

Evaluation of the safety and feasibility of electrochemotherapy with intravenous bleomycin as local treatment of bladder cancer in dogs

Local treatment of canine urothelial carcinoma (UC) of the bladder is a challenge. More than 90% of the cases invade the muscular layer, more than 50% develop on bladder sites with a difficult surgical approach and often requiring radical surgical procedures. This study aims to evaluate the safety and feasibility of electrochemotherapy (ECT) with intravenous bleomycin (BLM) as a local therapy for bladder UC. This prospective study included 21 dogs with spontaneous bladder UC. Regional/distant metastases and neoplastic infiltration of the serosa was considered the main exclusion criteria. We had no deaths during ECT or in the immediate postoperative period, and no suture dehiscence. Most dogs (19/21) developed mild adverse effects, whereas two dogs developed ureteral stenosis. Complete response (CR) was achieved in 62% of the cases (13/21), while partial response (PR) was achieved in 24% (5/21). The median survival and disease-free survival times were 284 and 270 days, respectively. Overall survival was significantly better in the dogs who achieved a CR. In conclusion, ECT was well-tolerated in dogs with UC, demonstrating its safety and feasibility. These data pave the way for new studies aimed at evaluating the effectiveness of ECT in canine bladder UC as a translational model for human disease.

Immunohistochemical analysis of expression of VEGFR2, KIT, PDGFR-β, and CDK4 in canine urothelial carcinoma

Urothelial carcinomas (UCs), also known as transitional cell carcinomas, are the most common canine urinary tract neoplasms. Tyrosine kinases (TKs) are enzymes that tightly regulate cell growth and differentiation through phosphorylation. Receptor TK (RTK) inhibitors are currently used to treat UCs. Toceranib phosphate (Palladia; Pfizer) is an RTK inhibitor that blocks the activity of vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor-alpha and -beta (PDGFR-α, -β), FMS-like tyrosine kinase 3, stem cell factor receptor (KIT, kinase inhibitor targeting), and colony stimulating factor receptor. To better understand UCs and validate treatment targets, we performed immunohistochemical staining for RTKs, as well as a novel target, cyclin-dependent kinase 4 (CDK4, a central regulator of the mammalian cell cycle), on formalin-fixed, paraffin-embedded tissues from bladder biopsies from 17 dogs with UCs, 17 dogs with cystitis (diseased controls), and 8 normal dogs (negative controls). Although immunohistochemical scores could not be extrapolated to prognostic value, response to treatment, and outcome of patients with UC, we demonstrated expression of PDGFR-β and VEGFR2 in UCs; all UC samples staining positively for VEGFR2. Minimal positive staining for KIT was noted in the tumor samples. CDK4 staining intensity was significantly weaker in UCs compared with normal and cystitis bladder samples. The intense staining of VEGFR2 in UC cells suggested that VEGFR2 may be of prognostic and/or therapeutic value in dogs with UC. Overexpression of VEGFR2 in UC cells validates this receptor as a treatment target in UC.

Selective inhibition of integrin αvβ6 leads to rapid induction of urinary bladder tumors in cynomolgus macaques

Administration of a novel and selective small molecule integrin αvβ6 inhibitor, MORF-627, to young cynomolgus monkeys for 28 days resulted in the rapid induction of epithelial proliferative changes in the urinary bladder of 2 animals, in the absence of test agent genotoxicity. Microscopic findings included suburothelial infiltration by irregular nests and/or trabeculae of epithelial cells, variable cytologic atypia, and high mitotic rate, without invasion into the tunica muscularis. Morphologic features and patterns of tumor growth were consistent with a diagnosis of early-stage invasive urothelial carcinoma. Ki67 immunohistochemistry demonstrated diffusely increased epithelial proliferation in the urinary bladder of several monkeys, including those with tumors, and αvβ6 was expressed in some epithelial tissues, including urinary bladder, in monkeys and humans. Spontaneous urothelial carcinomas are extremely unusual in young healthy monkeys, suggesting a direct link of the finding to the test agent. Inhibition of integrin αvβ6 is intended to locally and selectively block transforming growth factor beta (TGF-β) signaling, which is implicated in epithelial proliferative disorders. Subsequent in vitro studies using a panel of integrin αvβ6 inhibitors in human bladder epithelial cells replicated the increased urothelial proliferation observed in monkeys and was reversed through exogenous application of TGF-β. Moreover, analysis of in vivo models of liver and lung fibrosis revealed evidence of epithelial hyperplasia and cell cycle dysregulation in mice treated with integrin αvβ6 or TGF-β receptor I inhibitors. The cumulative evidence suggests a direct link between integrin αvβ6 inhibition and decreased TGF-β signaling in the local bladder environment, with implications for epithelial proliferation and carcinogenesis.

Identification of a naturally-occurring canine model for early detection and intervention research in high grade urothelial carcinoma

Background

Early detection and intervention research is expected to improve the outcomes for patients with high grade muscle invasive urothelial carcinoma (InvUC). With limited patients in suitable high-risk study cohorts, relevant animal model research is critical. Experimental animal models often fail to adequately represent human cancer. The purpose of this study was to determine the suitability of dogs with high breed-associated risk for naturally-occurring InvUC to serve as relevant models for early detection and intervention research. The feasibility of screening and early intervention, and similarities and differences between canine and human tumors, and early and later canine tumors were determined.

Methods

STs (n=120) ≥ 6 years old with no outward evidence of urinary disease were screened at 6-month intervals for 3 years with physical exam, ultrasonography, and urinalysis with sediment exam. Cystoscopic biopsy was performed in dogs with positive screening tests. The pathological, clinical, and molecular characteristics of the "early" cancer detected by screening were determined. Transcriptomic signatures were compared between the early tumors and published findings in human InvUC, and to more advanced "later" canine tumors from STs who had the typical presentation of hematuria and urinary dysfunction. An early intervention trial of an oral cyclooxygenase inhibitor, deracoxib, was conducted in dogs with cancer detected through screening.

Results

Biopsy-confirmed bladder cancer was detected in 32 (27%) of 120 STs including InvUC (n=29, three starting as dysplasia), grade 1 noninvasive cancer (n=2), and carcinoma in situ (n=1). Transcriptomic signatures including druggable targets such as EGFR and the PI3K-AKT-mTOR pathway, were very similar between canine and human InvUC, especially within luminal and basal molecular subtypes. Marked transcriptomic differences were noted between early and later canine tumors, particularly within luminal subtype tumors. The deracoxib remission rate (42% CR+PR) compared very favorably to that with single-agent cyclooxygenase inhibitors in more advanced canine InvUC (17-25%), supporting the value of early intervention.

Conclusions

The study defined a novel naturally-occurring animal model to complement experimental models for early detection and intervention research in InvUC. Research incorporating the canine model is expected to lead to improved outcomes for humans, as well as pet dogs, facing bladder cancer.

The miRNome of canine invasive urothelial carcinoma

Urothelial carcinoma (UC) comprises up to 2% of all naturally occurring neoplasia in dogs and can be challenging to diagnose. MicroRNAs (miRNAs) have been reported to be dysregulated in numerous diseases, including neoplasia. MiRNA expression has been evaluated in human UC, but there is limited information regarding the miRNA transcriptome of UC in dogs. Our study aimed to evaluate differential miRNA expression in bladder tissue collected from normal canine urothelium and canine invasive UC (iUC) to elucidate the dysregulated pathways in canine UC. Next-Generation RNA sequencing (RNA-Seq) was performed for dogs with UC (n = 29) and normal canine urothelium (n = 4). Raw RNA data were subjected to normalization, and pairwise comparison was performed using EdgeR with Benjamini-Hochberg FDR multiple testing correction (p < 0.05; >2-fold change) comparing tissue samples of normal urothelium to canine iUC samples. Principal component analysis and hierarchical cluster analysis were performed. MiRNA of FFPE tissue samples of separate iUC (n = 5) and normal urothelium (n = 5) were used to evaluate five miRNAs using RT-qPCR. Pathway analysis was performed utilizing miRWalk, STRING database, and Metascape utilizing KEGG pathways and GO terms databases. Twenty-eight miRNAs were differentially expressed (DE) by RNA-Seq. RT-qPCR confirmed that four miRNAs are significantly downregulated in UC compared to healthy urothelial samples (miR-105a, miR-143, miR-181a, and miR-214). Principal component analysis and hierarchical cluster analysis showed separation between miRNAs in iUC and the control group. The DE miRNAs are most often associated with gene silencing by miRNA, miRNAs in cancer, and miRNAs involved in DNA damage responses. Proteins involved include HRAS, KRAS, ARAF, RAF1, MAPK1, MAP2K1, MAPK3, FGFR3, EGFR, HBEGF, RASSF1, E2F2, E2F3, ERBB2, SRC, MMP1, and UP3KA. The differential expression of miRNAs in canine iUC compared to normal canine urothelial tissue indicates that these markers should be further evaluated for their potential role as diagnostic and therapeutic targets.

Fluorescence-Based Microendoscopic Sensing System for Minimally Invasive In Vivo Bladder Cancer Diagnosis

Bladder cancer is commonly diagnosed by evaluating the tissue morphology through cystoscopy, and tumor resection is used as the primary treatment approach. However, these methods are limited by lesion site specificity and resection margin, and can thereby fail to detect cancer lesions at early stages. Nevertheless, rapid diagnosis without biopsy may be possible through fluorescence sensing. Herein, we describe a minimally invasive imaging system capable of sensing even small tumors through a 1.2 mm diameter flexible fiber bundle microprobe. We demonstrate that this new device can be used for the early diagnosis of bladder cancer in rats. Bladder cancer was induced in rats using the carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN), and a togglable filter capable of PpIX fluorescence sensing was installed in the microendoscopic system. Following 5-aminolevulinic acid administration, tissue in the early stages of bladder cancer was successfully identified with fluorescence detection and confirmed with hematoxylin/eosin and ferrochelatase staining. Although the time required for BBN to induce bladder cancer varied between 3 and 4 weeks among the rats, the microendoscopic system allowed the minimally invasive follow-up on cancer development.

Grading Systems for Canine Urothelial Carcinoma of the Bladder: A Comparative Overview

The relationship between tumor morphology and clinical behavior is a key point in oncology. In this scenario, pathologists and clinicians play a pivotal role in the identification and testing of reliable grading systems based on standardized parameters to predict patient prognosis. Dogs with bladder urothelial carcinoma (BUC) were recently proposed as a "large animal" model for the study of human BUCs due to the similar morphology and metastasis locations. BUC grading systems are consolidated in human medicine, while in veterinary medicine, the BUC grading systems that have been proposed for canine tumors are not yet applied in routine diagnostics. These latter systems have been proposed, decade by decade, over the last thirty years, and the reason for their scarce application is mainly related to a lack of specific cutoff values and studies assessing their prognostic relevance. However, for any prognostic study, reliable grading is necessary. The aim of the present article was to give an overview of the BUC grading systems available in both human and veterinary pathology and provide an extensive description and a critical evaluation to support veterinary researchers in the choice of possible grading systems to apply in future studies on canine BUCs.

International Society of Urological Pathology Expert Opinion on Grading of Urothelial Carcinoma

CONTEXT

Grading is the mainstay for treatment decisions for patients with non-muscle-invasive bladder cancer (NMIBC).

OBJECTIVE

To determine the requirements for an optimal grading system for NMIBC via expert opinion.

EVIDENCE ACQUISITION

A multidisciplinary working group established by the International Society of Urological Pathology reviewed available clinical, histopathological, and molecular evidence for an optimal grading system for bladder cancer.

EVIDENCE SYNTHESIS

Bladder cancer grading is a continuum and five different grading systems based on historical grounds could be envisaged. Splitting of the World Health Organization (WHO) 2004 low-grade class for NMIBC lacks diagnostic reproducibility and molecular-genetic support, while showing little difference in progression rate. Subdividing the clinically heterogeneous WHO 2004 high-grade class for NMIBC into intermediate and high risk categories using the WHO 1973 grading is supported by both clinical and molecular-genetic findings. Grading criteria for the WHO 1973 scheme were detailed on the basis of literature findings and expert opinion.

CONCLUSIONS

Splitting of the WHO 2004 high-grade category into WHO 1973 grade 2 and 3 subsets is recommended. Provision of more detailed histological criteria for the WHO 1973 grading might facilitate the general acceptance of a hybrid four-tiered grading system or-as a preferred option-a more reproducible three-tiered system distinguishing low-, intermediate (high)-, and high-grade NMIBC.

PATIENT SUMMARY

Improvement of the current systems for grading bladder cancer may result in better informed treatment decisions for patients with bladder cancer.

Molecular Markers in Urinary Bladder Cancer: Applications for Diagnosis, Prognosis and Therapy

Cancer of the urinary bladder is a neoplasm with considerable importance in veterinary medicine, given its high incidence in several domestic animal species and its life-threatening character. Bladder cancer in companion animals shows a complex and still poorly understood biopathology, and this lack of knowledge has limited therapeutic progress over the years. Even so, important advances concerning the identification of tumour markers with clinical applications at the diagnosis, prognosis and therapeutic levels have recently been made, for example, the identification of pathological BRAF mutations. Those advances are now facilitating the introduction of targeted therapies. The present review will address such advances, focusing on small animal oncology and providing the reader with an update on this field. When appropriate, comparisons will be drawn with bladder cancer in human patients, as well as with experimental models of the disease.

The impact of grading scheme on non-muscle invasive bladder cancer progression: potential utility of hybrid grading schemes

Non-muscle invasive bladder cancer (NMIBC) grade is a major determinant of progression risk. The most widely utilised grading systems are the World Health Organization (WHO) 1973 and 2004 schemes. Recent publications suggest the utility of combining both into a four-tier or a hybrid three-tier system, subdividing WHO 2004 high grade into two separate categories while maintaining low grade as a single group. We identified two retrospective cohorts of bladder resections/biopsies of papillary urothelial NMIBC with long term clinical follow-up. The sentinel specimen was assessed for WHO 2004 and 1973 grade, along with pathological stage and carcinoma in situ. Each case was additionally stratified into a hybrid three-tier system (low grade; high grade, grades 2 and 3) and a four-tier system (low grade, grades 1 and 2; high grade, grades 2 and 3). Uni- and multivariable analysis for progression and event free survival (PFS/EFS) were calculated along with the time dependent area under the curve (AUC) for each grading scheme. There were 609 cases (Cohort A, n=343; Cohort B, n=266), including 449 (74%) pTa, 156 pT1 (26%) and four pTx with 338 (56%) low grade (177, grade 1; 161, grade 2) and 271 (44%) high grade (137, grade 2; 134, grade 3). A total of 108 patients progressed (17.7%): 97 high grade, (grade 3, n=59; grade 2, n=38). Multivariable analyses of PFS with the hybrid 3- and 4-tier systems showed higher Harrell's concordance indices (0.851 and 0.853, respectively) than WHO 1973 (0.844) and WHO 2004 (0.846). In both cohorts AUC values were higher (0.77-0.85) for the two hybrid grading systems compared to WHO 1973 or WHO 2004 (0.72-0.82). Similar results were seen on analysis of EFS. The data support the use of a hybrid three-tier or four-tier grading system to improve stratification of NMIBC patients.

Molecular Classification of Bladder Urothelial Carcinoma Using NanoString-Based Gene Expression Analysis

Simple Summary

Our study aimed to apply a quantitative method based on mRNA counting as nCounter (NanoString Technologies, Inc). This method can obtain precise and accurate measures of RNA expression compared to RT-PCR, and which might represent an alternative to the NGS-genomic/transcriptomic profiling frequently used to generate molecular data in bladder cancer and provide clinically meaningful datasets for the molecular classification of bladder cancer. The current study generated a four-gene classifier, incorporating GATA3 and KRT20 (typically related to luminal molecular subtype) and KRT5 and KRT14 (typically related to basal molecular subtype). This methodology allowed us to explore differences in clinicopathologic parameters and potential sensitivities to ICI immunotherapy in a cohort series of 91 urothelial carcinomas of the bladder.

Abstract

Molecular classification of bladder carcinoma is a relevant topic in modern bladder cancer oncology due to its potential to improve oncological outcomes. The available molecular classifications are generally based on transcriptomic profiles, generating highly diverse categories with limited correlation. Implementation of molecular classification in practice is typically limited due to the high complexity of the required technology, the elevated costs, and the limited availability of this technology worldwide. We have conducted a gene expression analysis using a four-gene panel related to luminal and basal subtypes in a series of 91 bladder cancer cases. NanoString-based gene expression analysis using typically luminal (GATA3+/KRT20+) and basal markers (KRT14+/KRT5+/GATA3low/-/KRT20low/-) classified urothelial bladder carcinoma samples as luminal, basal, and a third category (KRT14-/KRT5-/GATA3-/KRT20-), null/double negative (non-luminal/non-basal). These three categories were meaningful in terms of overall cancer-specific survival (p < 0.0001) or when classified as conventional urothelial carcinoma and variant histology urothelial carcinoma (p < 0.0001), NMIBC vs. MIBC (p < 0.001), or by AJCC stage category Ta (p = 0.0012) and T1 (p < 0.0001) but did not reach significance in T2-T4 (p = 0.563). PD-L1 expression (low vs. high) was also different according to molecular subtype, with high PD-L1 expression mostly seen in basal and null subtypes and carcinomas with variant histology (p = 0.002). Additionally, the luminal subtype was enriched in NMIBC with favorable cancer-specific survival (p < 0.0001). In contrast, basal and null subtypes resulted in aggressive MIBC tumors with shorter cancer-specific survival (p < 0.0001), some of which presented variant histology. In conclusion, a comprehensive evaluation of a gene classifier related to molecular taxonomy using NanoString technology is feasible. Therefore, it might represent an accessible and affordable tool in this rapidly expanding area of precision genomics.

Basal and Luminal Molecular Subtypes in Naturally-Occurring Canine Urothelial Carcinoma are Associated with Tumor Immune Signatures and Dog Breed

BACKGROUND

Improved therapies are needed for patients with invasive urothelial carcinoma (InvUC). Tailoring treatment to molecular subtypes holds promise, but requires further study, including studies in pre-clinical animal models. Naturally-occurring canine InvUC harbors luminal and basal subtypes, mimicking those observed in humans, and could offer a relevant model for the disease in people.

OBJECTIVE

To further validate the canine InvUC model, clinical and tumor characteristics associated with luminal and basal subtypes in dogs were determined, with comparison to findings from humans.

METHODS

RNA sequencing (RNA-seq) analyses were performed on 56 canine InvUC tissues and bladder mucosa from four normal dogs. Data were aligned to CanFam 3.1, and differentially expressed genes identified. Data were interrogated with panels of genes defining luminal and basal subtypes, immune signatures, and other tumor features. Subject and tumor characteristics, and outcome data were obtained from medical records.

RESULTS

Twenty-nine tumors were classified as luminal and 27 tumors as basal subtype. Basal tumors were strongly associated with immune infiltration (OR 52.22, 95%CI 4.68-582.38, P = 0.001) and cancer progression signatures in RNA-seq analyses, more advanced clinical stage, and earlier onset of distant metastases in exploratory analyses (P = 0.0113). Luminal tumors were strongly associated with breeds at high risk for InvUC (OR 0.06, 95%CI 0.01 -0.37, P = 0.002), non-immune infiltrative signatures, and less advanced clinical stage.

CONCLUSIONS

Dogs with InvUC could provide a valuable model for testing new treatment strategies in the context of molecular subtype and immune status, and the search for germline variants impacting InvUC onset and subtype.

Phase I/II Trial of Vemurafenib in Dogs with Naturally Occurring, BRAF-mutated Urothelial Carcinoma

BRAF-targeted therapies including vemurafenib (Zelboraf) induce dramatic cancer remission; however, drug resistance commonly emerges. The purpose was to characterize a naturally occurring canine cancer model harboring complex features of human cancer, to complement experimental models to improve BRAF-targeted therapy. A phase I/II clinical trial of vemurafenib was performed in pet dogs with naturally occurring invasive urothelial carcinoma (InvUC) harboring the canine homologue of human BRAF ^V600E The safety, MTD, pharmacokinetics, and antitumor activity were determined. Changes in signaling and immune gene expression were assessed by RNA sequencing and phosphoproteomic analyses of cystoscopic biopsies obtained before and during treatment, and at progression. The vemurafenib MTD was 37.5 mg/kg twice daily. Anorexia was the most common adverse event. At the MTD, partial remission occurred in 9 of 24 dogs (38%), with a median progression-free interval of 181 days (range, 53-608 days). In 18% of the dogs, new cutaneous squamous cell carcinoma and papillomas occurred, a known pharmacodynamic effect of vemurafenib in humans. Upregulation of genes in the classical and alternative MAPK-related pathways occurred in subsets of dogs at cancer progression. The most consistent transcriptomic changes were the increase in patterns of T lymphocyte infiltration during the first month of vemurafenib, and of immune failure accompanying cancer progression. In conclusion, the safety, antitumor activity, and cutaneous pharmacodynamic effects of vemurafenib, and the development of drug resistance in dogs closely mimic those reported in humans. This suggests BRAF-mutated canine InvUC offers an important complementary animal model to improve BRAF-targeted therapies in humans.

Molecular pathology of urothelial carcinoma

The current personalized oncology era has witnessed significant efforts to integrate clinical, pathological, and molecular classifications. The growing need for molecular biomarkers to feed personalized oncology, together with the unprecedented wealth of knowledge on the molecular basis of bladder cancer, has led to a novel approach to this disease, incorporating molecularly generated data in clinical practice for locally advanced or metastatic disease. Translational research allows a better understanding of the early events in the development of urothelial carcinoma in the urinary bladder. Thus, mutations in the KMT2D and KDM6A chromatin-modifying genes confer competitive advantages that drive cells to colonize larger regions of the urothelium. Additional mutations in TP53, PIK3CA, FGFR3, or RB1 genes then trigger the process of malignant transformation in the urothelium. In the current review, we provide an overview of what could be the expected transition from the morphology-based classification to a combined, molecularly enriched reporting of clinically meaningful parameters aiming to promote personalized oncology of urothelial carcinoma.

Noninvasive low-grade papillary urothelial carcinoma with degenerative nuclear atypia: a grading pitfall

Noninvasive low-grade papillary urothelial carcinoma is a papillary neoplasm with orderly appearance and mild nuclear pleomorphism. Some cases show significant nuclear pleomorphism with degenerative atypia leading to grading difficulties. A retrospective review of the pathology files identified 16 cases diagnosed as noninvasive low-grade papillary urothelial carcinoma with degenerative atypia. Fifteen cases were consults. The average age was 46 years (range 19-78). The average size was 1.7 cm (range: 0.3-3.5). The submitting diagnoses in consults were noninvasive high-grade papillary urothelial carcinoma (n = 6), condyloma (n = 1), atypical papillary lesion (n = 1), prominent umbrella cells (n = 1), and not given (n = 6). Ki-67 proliferation rate was <5% in 10 of 10 cases (100%), and the cells with large atypical nuclei were negative. Microscopically, there were scattered cells with nuclei larger than 5 times the size of stromal lymphocytes but displayed smudgy chromatin and occasional multinucleation and intranuclear vacuoles. Next-generation sequencing identified the following mutations: HRAS (n = 4), FGFR3 (n = 3), KRAS (n = 3), BRAF (n = 1), PDGFRA (n = 1), and PIK3CA (n = 1). Other deleterious mutations were identified, but none in genes characteristic of high-grade tumors. Follow-up was available in 6 patients (median 32 months). One patient recurred with a noninvasive low-grade papillary urothelial carcinoma 20 months after the index case. All the remaining patients had no evidence of disease at the last follow-up. No patient died or had disease progression. The combination of preservation of polarity, low mitotic activity, Ki-67 <5% with the larger atypical nuclei negative for Ki-67, along with nuclear atypia that is degenerative are features used to classify these tumors as low grade.

Predicting Diagnosis of Australian Canine and Feline Urinary Bladder Disease Based on Histologic Features

Anatomic pathology is a vital component of veterinary medicine but as a primarily subjective qualitative or semiquantitative discipline, it is at risk of cognitive biases. Logistic regression is a statistical technique used to explain relationships between data categories and outcomes and is increasingly being applied in medicine for predicting disease probability based on medical and patient variables. Our aims were to evaluate histologic features of canine and feline bladder diseases and explore the utility of logistic regression modeling in identifying associations in veterinary histopathology, then formulate a predictive disease model using urinary bladder as a pilot tissue. The histologic features of 267 canine and 71 feline bladder samples were evaluated, and a logistic regression model was developed to identify associations between the bladder disease diagnosed, and both patient and histologic variables. There were 102 cases of cystitis, 84 neoplasia, 42 urolithiasis and 63 normal bladders. Logistic regression modeling identified six variables that were significantly associated with disease outcome: species, urothelial ulceration, urothelial inflammation, submucosal lymphoid aggregates, neutrophilic submucosal inflammation, and moderate submucosal hemorrhage. This study demonstrated that logistic regression modeling could provide a more objective approach to veterinary histopathology and has opened the door toward predictive disease modeling based on histologic variables.

Stage T1 bladder cancer: diagnostic criteria and pitfalls

Accurate pathological staging is crucial for patient management. Patients with T1 bladder cancer are at risk of recurrence, progression, and death of cancer. Recognition of early invasion (stage T1 disease) in urothelial carcinoma remains one of the most challenging areas in urological surgical pathology practice. A logical roadmap to T1 diagnosis would include careful evaluation of histological grade, stromal epithelial interface, characteristics of the invading epithelium, and the stroma associated responses. Tangential sectioning, crush and cautery artifacts, and associated inflammatory infiltrate are commonly encountered problems and the source of pitfalls. In this review, we outline diagnostic criteria, common pitfalls, and different histological patterns of invasion into the lamina propria. Current recommendations on reporting of biopsy and transurethral resection specimens, molecular biomarkers, clinical implications of T1 cancer diagnosis and recent developments on the T1 substaging are also discussed. Most T1 bladder cancer patients will benefit from conservative management after restaging transurethral resection of bladder and bacillus Calmette-Guérin maintenance. Patients with high risk features, such as concurrent urothelial carcinoma in situ, increased depth of invasion, lymphovascular invasion, and variant histology among others, should be considered for early cystectomy.

Reappraisal of the papillary urothelial neoplasm of low malignant potential (PUNLMP)

Although the papillary urothelial neoplasm of low malignant potential (PUNLMP) diagnostic category was retained in the updated 2016 World Health Organisation (WHO) classification of tumours of the urinary system, there still exists a great deal of controversy regarding the biological behaviour of these tumours. We review PUNLMP tumours and histological grading with an emphasis on the histomorphological, genetic and clinical similarities between PUNLMP and low-grade non-invasive papillary urothelial carcinoma. A literature search using PubMed was performed. All relevant literature concerning PUNLMP and the grading of urothelial tumours was reviewed. PUNLMPs cannot be reliably distinguished from low-grade non-invasive papillary urothelial carcinomas based on the histomorphological criteria outlined in the WHO 2004/2016 classification system. PUNLMPs and low-grade non-invasive papillary urothelial carcinomas are not only morphologically similar, but also share similar molecular genetic alterations and a similar risk of recurrence and progression. In addition, there are no consensus recommendations for a different method of treatment and follow-up for these two tumour types. Attempting to distinguish PUNLMP from low-grade papillary urothelial carcinoma adds an unnecessary level of complexity to the grading and classification of urothelial tumours. We feel that PUNLMP terminology should be abandoned and that all such tumours should be classified as low-grade carcinomas until more objective determinants of clinical outcome can be established.

Updates in Histologic Grading of Urologic Neoplasms

CONTEXT.—

Tumor histology offers a composite view of the genetic, epigenetic, proteomic, and microenvironmental determinants of tumor biology. As a marker of tumor histology, histologic grading has persisted as a highly relevant factor in risk stratification and management of urologic neoplasms (ie, renal cell carcinoma, prostatic adenocarcinoma, and urothelial carcinoma). Ongoing research and consensus meetings have attempted to improve the accuracy, consistency, and biologic relevance of histologic grading, as well as provide guidance for many challenging scenarios.

OBJECTIVE.—

To review the most recent updates to the grading system of urologic neoplasms, including those in the 2016 4th edition of the World Health Organization (WHO) Bluebook, with emphasis on issues encountered in routine practice.

DATA SOURCES.—

Peer-reviewed publications and the 4th edition of the WHO Bluebook on the pathology and genetics of the urinary system and male genital organs.

CONCLUSIONS.—

This article summarizes the recently updated grading schemes for renal cell carcinoma, prostate adenocarcinomas, and bladder neoplasms of the genitourinary tract.

Assessing CD 10 Expression Level and Its Prognostic Impact in Egyptian Patients with Urothelial Carcinoma

Background and aim:

CD10 is expressed in urothelial carcinoma cells and cancer associated fibroblasts (CAF). In the current study, CD10 immunohistochemical staining (IHC) and CD10 mRNA expression in urothelial carcinoma of bladder (UCB) were assessed, and its relationship with tumor progression and prognosis was investigated.

Patients and Methods:

In this study, 106 formalin fixed paraffin-embedded (FFPE) tissue of UCB, obtained through radical cystectomy specimen, and 10 matched normal tissue samples were included.CD10 expression was evaluated by immunohistochemistry and real time PCR techniques.

Results:

CD10 expression in tumor cells and associated stromal fibroblasts was significantly associated with high tumor grade and advanced stage. Significant correlation was found between CD10 tumor expression and lymphovascular invasion (LVI) (P<0.001) as well as perineural invasion (PNI). CD10 expression in stromal fibroblasts was significantly associated with squamous differentiation of tumor cells, lymph node metastasis (LNM), and tumor necrosis. Positive CD10 expression in both tumor cells and associated stromal fibroblasts was associated with shorter OS . CD10 mRNA was overexpressed in tumors in comparison with the matched normal tissues. CD10 mRNA was significantly higher in invasive tumor, advanced stage tumor, and high grade tumor. There was significant correlation between CD10 mRNA tumor expression and LVI, PNI, and tumor recurrence.

Conclusion:

Increased expression of CD10 in the tumor and CAF was strongly correlated with tumor progression, invasion, metastasis, shorter OS, and RFS in urothelial carcinoma patients. CD10 mRNA showed significantly higher expression in tumor tissue than in matched normal tissue. CD10 mRNA was associated with depth of invasion, TNM stage, tumor grade, vascular tumor invasion, and tumor recurrence.

CK14 Expression Identifies a Basal/Squamous-Like Type of Papillary Non-Muscle-Invasive Upper Tract Urothelial Carcinoma

Object: CK14 expression is an important marker of basal/squamous-like (BASQ)-type muscle-invasive bladder carcinoma, and this molecularly defined subtype has a poor prognosis and a distinct response to chemotherapy. However, CK14 expression and its clinicopathological and molecular significance in papillary non-muscle-invasive upper tract urothelial carcinoma (NMIUTUC) remain unknown. Herein, we investigated the prognostic implications of immunohistochemical (IHC) staining for CK14 and the transcriptional characteristics associated with CK14 expression in papillary NMIUTUC. Materials and Methods: IHC staining for CK14 was conducted in 204 papillary NMIUTUC specimens. Positive CK14 IHC staining was defined as a positive signal in >0% of tumor cells. RNA sequencing data were analyzed from 8 papillary high-grade NMIUTUC specimens consisting of 4 CK14-positive and 4 CK14-negative tumors. Results: CK14 positivity was associated with a high TNM stage (p < 0.001) and a high World Health Organization grade (p = 0.003). Survival analysis showed that CK14 positivity was significantly associated with poor progression-free survival (p = 0.015; hazard ratio [HR] = 2.990; 95% confidence interval [CI] = 1.180-7.580) and was marginally associated with poor cancer-specific survival (p = 0.052; HR = 3.77; 95% CI = 0.900-15.780). Gene set enrichment analysis demonstrated that the CK14-positive tumors were associated with a basal subtype of breast cancer, squamous cell carcinoma development, p40, tumor necrosis factor α-nuclear factor-κB, and p53 pathways, and embryonic stem cells; these characteristics are reminiscent of the BASQ subtype. In addition, with a p < 0.05 and |fold change| ≥2 as the cutoffs, we identified 178 differentially expressed genes when comparing CK14-positive and CK14-negative tumors. Functional analysis of these genes revealed several networks and gene ontology terms related to the positive regulation of cellular proliferation in CK14-positive tumors. Consistent with these results, we demonstrated that the mean Ki-67 proliferative index was higher in CK14-positive tumors than it was in CK14-negative tumors (2.3 vs. 0.8%, respectively, p = 0.002). Conclusion: CK14-positive papillary NMIUTUC is an aggressive subtype with BASQ-like molecular characteristics and dynamic proliferative activity. We propose that CK14 IHC staining can be a useful biomarker of BASQ-type papillary NMIUTUC that can be applied in daily practice with the aim of precision oncology.

Naturally-Occurring Invasive Urothelial Carcinoma in Dogs, a Unique Model to Drive Advances in Managing Muscle Invasive Bladder Cancer in Humans

There is a great need to improve the outlook for people facing urinary bladder cancer, especially for patients with invasive urothelial carcinoma (InvUC) which is lethal in 50% of cases. Improved outcomes for patients with InvUC could come from advances on several fronts including emerging immunotherapies, targeted therapies, and new drug combinations; selection of patients most likely to respond to a given treatment based on molecular subtypes, immune signatures, and other characteristics; and prevention, early detection, and early intervention. Progress on all of these fronts will require clinically relevant animal models for translational research. The animal model(s) should possess key features that drive success or failure of cancer drugs in humans including tumor heterogeneity, genetic-epigenetic crosstalk, immune cell responsiveness, invasive and metastatic behavior, and molecular subtypes (e.g., luminal, basal). Experimental animal models, while essential in bladder cancer research, do not possess these collective features to accurately predict outcomes in humans. These key features, however, are present in naturally-occurring InvUC in pet dogs. Canine InvUC closely mimics muscle-invasive bladder cancer in humans in cellular and molecular features, molecular subtypes, immune response patterns, biological behavior (sites and frequency of metastasis), and response to therapy. Thus, dogs can offer a highly relevant animal model to complement other models in research for new therapies for bladder cancer. Clinical treatment trials in pet dogs with InvUC are considered a win-win-win scenario; the individual dog benefits from effective treatment, the results are expected to help other dogs, and the findings are expected to translate to better treatment outcomes in humans. In addition, the high breed-associated risk for InvUC in dogs (e.g., 20-fold increased risk in Scottish Terriers) offers an unparalleled opportunity to test new strategies in primary prevention, early detection, and early intervention. This review will provide an overview of canine InvUC, summarize the similarities (and differences) between canine and human InvUC, and provide evidence for the expanding value of this canine model in bladder cancer research.

Characterization of mRNA Expression and Endogenous RNA Profiles in Bladder Cancer Based on The Cancer Genome Atlas (TCGA) Database

Background

Bladder cancer is a multifactorial disease with increasing incidence and mortality. Genetic alterations and altered expressions of mRNAs, long non-coding RNAs (lncRNAs), and miRNAs have been shown to play important roles in the tumorigenesis of bladder cancer. However, the functions of key RNAs and their regulatory network in bladder cancer are still to be elucidated.

Material/Methods

RNA profiles were downloaded from The Cancer Genome Atlas (TCGA) database. The differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer were acquired through analyses of data from 414 bladder cancer tissues and 19 normal bladder tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed by using “DAVID6.8” and the R package “ClusterProfile”. Protein–protein interaction and competing endogenous RNA (ceRNA) networks were constructed by using “STRING” database and Cytoscape 3.6.2. Based on the clinical data and Cox regression, a prognosis model was established, and survival analysis was performed.

Results

A total of 1819 mRNAs, 659 lncRNAs, and 160 miRNAs were identified as significantly differentially expressed in bladder cancer of which 52 mRNAs, 58 lncRNAs, and 22 miRNAs were incorporated in the ceRNA network. CFL2 and TPM2 were found to be downregulated and showed significant correlation to each other in bladder cancer. HOXB5 and 6 lncRNAs (ADAMTS9-AS1, AC112721.1, LINC00460, AC110491.1, LINC00163, and HCG22) were strongly associated with high-grade, disease stages, and overall survival.

Conclusions

In this study, we have identified differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer which were strongly associated with oncogenesis and prognosis. Further experimental studies are necessary to validate these results.

Staging of bladder cancer

Urothelial carcinoma of the urinary bladder is a heterogeneous disease with multiple possible treatment modalities and a wide spectrum of clinical outcome. Treatment decisions and prognostic expectations hinge on accurate and precise staging, and the recently published American Joint Committee on Cancer (AJCC) Staging Manual, 8th edition, should be the basis for staging of urinary bladder tumours. It is unfortunate that the International Union Against Cancer (UICC) 8th edition failed to incorporate new data which is considered in the AJCC 8th edition. Thus, the AJCC 8th edition is the focus of this review. Several critical changes and clarifications are made by the AJCC 8th edition relative to the 7th edition. Although the most obvious changes in the 8th edition are in the N (i.e. perivesical lymph node involvement now classified as N1) and M (i.e. M1 is subdivided into M1a and M1b) categories, several points are clarified in the T category (e.g. substaging of pT1 should be attempted). Further optimisation, however, is required. No particular method of substaging pT1 is formally recommended. In this review, these modifications are discussed, as well as points, which require further study and optimisation.

A study in a rat initiation-promotion bladder tumour model demonstrated no promoter/progressor potential of dapagliflozin

Dapagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor, is indicated to improve glycaemic control in adults of type 2 diabetes. In nonclinical studies, dapagliflozin was neither genotoxic nor carcinogenic. However, in some clinical studies, an increased incidence of bladder cancer was observed in the dapagliflozin group vs. the placebo. Therefore, this study was undertaken to determine if dapagliflozin can act as a promoter in a 2-stage bladder cancer model in rats induced with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Rats given BBN (100 or 400 mg/kg, po) twice weekly for 6 weeks in Phase 1 were assigned in Phase 2 to receive daily dose of vehicle, dapagliflozin (0.5 mg/kg, po) or uracil (positive control, 3% in diet) from weeks 8-34. All bladders were evaluated by histopathology. Verifying the validity of the model, uracil increased the incidence of bladder cancer, while dapagliflozin had no effect on the incidence or invasiveness of transitional cell carcinoma. The exposure of dapagliflozin at 0.5 mg/kg/day in rats was 7 times the clinical exposure at maximal therapeutic dose (10 mg). In conclusion, dapagliflozin does not act as promoter or progressor of bladder cancer in a validated bladder cancer model in rats.

SIU-ICUD on bladder cancer: pathology

Many changes have been made during these last years and concepts for understanding bladder cancer have evolved. We make an update with the latest findings of the WHO (World Health Organistaion) 2016, ICCR (International Collaboration on Cancer Reporting) and other official organisms and try to show the latest developments. In this document we provide new consensus guidelines and insights. We kept this document short and concise providing consensus guidelines to clinicians for the best patient care, it should be easy to understand for a non pathologists. We focussed on several burning issues, such as the anatomical and histological understanding of the bladder wall, the prognostic significance of grading and the most challenging problems in staging, we underline our needs from the clinicians such as clinical information, we further discuss the histological subtypes of bladder cancer, which is an extremely important issue in the light of molecular classifications and give prognostic insights. Furthermore, we discuss the ICCR worldwide consensus reporting, urinary cytology with the Paris system and several issues such as frozen section specimen.

Demographic and Survivorship Disparities in Non-muscle-invasive Bladder Cancer in the United States

Objectives

To examine survivorship disparities in demographic factors and risk status for non–muscle-invasive bladder cancer (NMIBC), which accounts for more than 75% of all urinary bladder cancers, but is highly curable with early identification and treatment.

Methods

We used the US National Cancer Institute’s Surveillance, Epidemiology, and End Results registries over a 19-year period (1988-2006) to examine survivorship disparities in age, sex, race/ethnicity, and marital status of patients and risk status classified by histologic grade, stage, size of tumor, and number of multiple primary tumors among NMIBC patients (n=29 326). We applied Kaplan-Meier (K-M) and Cox proportional hazard methods for survival analysis.

Results

Among all urinary bladder cancer patients, the majority of NMIBCs were in male (74.1%), non-Latino white (86.7%), married (67.8%), and low-risk (37.6%) to intermediate-risk (44.8%) patients. The mean age was 68 years. Survivorship (in median life years) was highest for non-Latino white (5.4 years), married (5.4 years), and low-risk (5.7 years) patients (K-M analysis, p<0.001). We found significantly lower survivorship for elderly, male (female hazard ratio [HR], 0.96), Latino (HR, 1.20), and unmarried (married HR, 0.93) patients.

Conclusions

Survivorship disparities were ubiquitous across age, sex, race/ethnicity, and marital status groups. Non-white, unmarried, and elderly patients had significantly shorter survivorship. The implications of these findings include the need for a heightened focus on health policy and more organized efforts to improve access to care in order to increase the chances of survival for all patients.

Nano-BCG: A Promising Delivery System for Treatment of Human Bladder Cancer

Mycobacterium bovis bacillus Calmette–Guerin (BCG) remains at the forefront of immunotherapy for treating bladder cancer patients. However, the incidence of recurrence and progression to invasive cancer is commonly observed. There are no established effective intravesical therapies available for patients, whose tumors recur following BCG treatment, representing an important unmet clinical need. In addition, there are very limited options for patients who do not respond to or tolerate chemotherapy due to toxicities, resulting in poor overall treatment outcomes. Within this context, nanotechnology is an emergent and promising tool for: (1) controlling drug release for extended time frames, (2) combination therapies due to the ability to encapsulate multiple drugs simultaneously, (3) reducing systemic side effects, (4) increasing bioavailability, (5) and increasing the viability of various routes of administration. Moreover, bladder cancer is often characterized by high mutation rates and over expression of tumor antigens on the tumor cell surface. Therapeutic targeting of these biomolecules may be improved by nanotechnology strategies. In this mini-review, we discuss how nanotechnology can help overcome current obstacles in bladder cancer treatment, and how nanotechnology can facilitate combination chemotherapeutic and BCG immunotherapies for the treatment of non-muscle invasive urothelial bladder cancer.

Phase distribution analysis of tissues based on the off-axis digital holographic hybrid reconstruction algorithm

Off-axis digital holography (DH) has great potential in histopathology for its high efficiency and precision. Phase distribution, usually extracted by the angular spectrum (AS) algorithm from a digital hologram, reflects important structural information of biological tissues. However, the complex structure of tissues introduces spectrum aliasing of the hologram, making the AS algorithm hard to realize and accurate phase analysis difficult to conduct. Here, we present a hybrid reconstruction algorithm, combining Fresnel reconstruction in spatial domain with the AS algorithm in frequency domain, to solve aliasing by spatial filtering. Through simulation, we demonstrate the feasibility and superiority of the hybrid algorithm and verified the precision (10^-3 rad) of the hybrid algorithm with spectrum aliasing. We extract phase distributions from normal urothelial and bladder cancer tissues by the hybrid algorithm and make quantitative analysis through histogram and standard deviation. The result shows the hybrid algorithm in off-axis DH has great advantage for the high-precision phase extraction of tissues and supplies significant information for cancer diagnosis.

Level of mitoses in non-muscle invasive papillary urothelial carcinomas (pTa and pT1) at initial bladder biopsy is a simple and powerful predictor of clinical outcome: a multi-center study in South Korea

BACKGROUND

Histologic grade is the most important predictor of the clinical outcome of non-muscle invasive (Ta, T1) papillary urothelial carcinoma (NMIPUCa), but its ambiguous criteria diminish its power to predict recurrence/progression for individual patients. We attempted to find an objective and reproducible histologic predictor of NMIPUCa that correlates well with the clinical outcome.

METHODS

A total of 296 PUCas were collected from the Departments of Surgical Pathology of 11 institutions in South Korea. The clinical outcome was grouped into no event (NE), recurrence (R), and progression (P) categories. All 25 histological parameters were numerically redefined. The clinical pathology of each case was reviewed individually by 11 pathologists from 11 institutions based on the 2004 WHO criteria and afterwards blindly evaluated by two participants, based on our proposed parameters. Univariate and multivariate logistic regression analyses were performed using the R software package.

RESULTS

The level of mitoses was the most reliable parameter for predicting the clinical outcome. We propose a four-tiered grading system based on mitotic count (> 10/10 high-power fields), nuclear pleomorphism (smallest-to-largest ratio of tumor nuclei >20), presence of divergent histology, and capillary proliferation (> 20 capillary lumina per papillary core).

CONCLUSIONS

The level of mitoses at the initial bladder biopsy and transurethral resection (TUR) specimen appeared to be an independent predictor of the Ta PUCa outcome. Other parameters include the number of mitoses, nuclear pleomorphism, divergent histology, and capillary proliferation within the fibrovascular core. These findings may improve selection of patients for a therapeutic strategy as compared to previous grading systems.

Laryngeal Dysplasia, Squamous Cell Carcinoma, and Variants

Squamous cell carcinoma (SCC) is a malignant epithelial tumor showing evidence of squamous differentiation. It is the most common malignancy of the larynx, with several variants (verrucous, exophytic or papillary, spindle-cell, basaloid, acantholytic, adenosquamous) recognized, with well-established precursor lesions. Dysplasia is now separated into only low-grade and high-grade categories. Each SCC variant has unique cytomorphologic features and histologic differential diagnoses that are important to consider, as management and outcomes are different.

Expression of human epidermal growth factor receptor 2 in bladder urothelial carcinoma

BACKGROUND

Urothelial bladder carcinoma (UBC) is one of the most prevalent cancers in men worldwide. Human epidermal growth factor receptor 2 (HER2) expression has been detected in a wide range of urothelial carcinoma. Despite many reports in the literature, the prognostic significance of this overexpression remains unclear. The aim of this study was to assess the expression of HER2 in urothelial bladder carcinomas and its association with clinical and pathological parameters.

METHODS

103 cases of UBC were diagnosed in our department between January 2014 and December 2015. The tumor specimens obtained by transurethral resection or cystectomy were evaluated by immunohistochemistry using HER2 antibody.

RESULTS

HER2 protein overexpression was present in 11.7% of cases and associated with tumor grade (p = 0.003) and pathological stage (p = 0.015). In multivariate analysis, HER2 overexpression was associated only with tumor grade (P = 0.04).

CONCLUSION

HER2 protein overexpression is noted in patients with high grade cancer. This expression may select patients for anti HER2 targeted therapy. Future larger and prospective studies will verify the frequency of HER2 alteration and the role of HER2 in the aggressive behavior.

Bladder cancer

Bladder cancer is a complex disease associated with high morbidity and mortality rates if not treated optimally. Awareness of haematuria as the major presenting symptom is paramount, and early diagnosis with individualised treatment and follow-up is the key to a successful outcome. For non-muscle-invasive bladder cancer, the mainstay of treatment is complete resection of the tumour followed by induction and maintenance immunotherapy with intravesical BCG vaccine or intravesical chemotherapy. For muscle-invasive bladder cancer, multimodal treatment involving radical cystectomy with neoadjuvant chemotherapy offers the best chance for cure. Selected patients with muscle-invasive tumours can be offered bladder-sparing trimodality treatment consisting of transurethral resection with chemoradiation. Advanced disease is best treated with systemic cisplatin-based chemotherapy; immunotherapy is emerging as a viable salvage treatment for patients in whom first-line chemotherapy cannot control the disease. Developments in the past 2 years have shed light on genetic subtypes of bladder cancer that might differ from one another in response to various treatments.

Skeletal Metastasis of Canine Urothelial Carcinoma: Pathologic and Computed Tomographic Features

Invasive urothelial (transitional cell) carcinoma (UC) is the most common cancer in the canine urinary tract. Prolonged survival of dogs with UC due to better management of the primary tumor and prevention of urethral obstruction might have contributed to an apparent increase in distant metastasis. Metastasis to bone is particularly concerning because the ensuing pain often leads to euthanasia; however, little is known of the frequency, site, or nature of UC skeletal metastasis. In a retrospective analysis, 17 (9%) of 188 canine UC cases had histologically confirmed skeletal metastasis, mainly to the vertebrae. In a prospective analysis of 21 dogs with UC that underwent total body computed tomography (CT) at euthanasia followed by a standardized pathologic examination, skeletal lesions detected on CT were suspected to be metastatic in 4 dogs and were confirmed as metastatic UC histologically in 3 (14%) dogs. In all 3 cases, skeletal metastasis had been suspected based on history and physical examination; however, 1 dog had additional CT-detected skeletal metastases in a clinically unsuspected location, and 2 dogs had histologically confirmed skeletal metastases that corresponded to nonspecific osseous lesions on CT. These findings suggest that total body CT could be helpful in detecting skeletal metastasis as a cause of bone pain in dogs with UC as well as in identifying clinically “silent” sites of skeletal metastasis.

Morphologic and Molecular Characteristics of Bladder Cancer

Bladder cancer is the fourth most common cancer in men, and is associated with significant morbidity and mortality. Pathologic evaluation of urothelial cancers relies predominantly on histomorphologic features but can be aided in a small subset of cases by immunohistochemical analyses. Distinction of papillary versus flat lesions, low-grade versus high-grade cytology, and histologic variants and the presence or absence of invasive tumor is important for proper clinical management. Advances in the molecular alterations associated with the various subtypes of urothelial carcinoma have been made but such studies are ongoing.

Long-term outcome of primary Papillary Urothelial Neoplasm of Low Malignant Potential (PUNLMP) including PUNLMP with inverted growth

BACKGROUND

Few larger studies have evaluated the long-term outcome after a diagnosis of papillary urothelial neoplasm of low malignant potential (PUNLMP), demonstrating a broad range of recurrence and progression rates. Additionally, no study has addressed the outcome of PUNLMP exhibiting inverted growth. We evaluated the long term clinical outcome of primary papillary urothelial neoplasm of low malignant potential (PUNLMP), including PUNLMP with inverted growth in a large single center study.

METHODS

We evaluated 189 primary PUNLMP (177 exophytic, 12 inverted), diagnosed from January 1, 2000 to December 31, 2009, in a centralized uropathology practice. We excluded PUNLMP diagnosed after a previous or with a concurrent urothelial neoplasm. Recurrence was defined as any subsequent urothelial neoplasm, regardless of the grade. Progression was defined as any subsequent higher-grade or invasive urothelial neoplasm. Recurrence and progression were established only if documented on a subsequent biopsy. Descriptive statistical analysis was performed using Microsof Excel software package.

RESULTS

The location of PUNLMP included bladder (187) and renal pelvis and ureter (1 each). After a median follow-up of 61 months (range, 9-128 months), 20.1% patients developed a recurrence. Recurrence with PUNLMP only was found in 9% of patients. Subsequent low-grade urothelial carcinoma was documented in 9.5% of patients. Progression to high-grade urothelial carcinoma was found in 1.6% patients (1% with muscle invasion). No patients with recurrent PUNLMP or subsequent low-grade carcinoma demonstrated invasion. All patients with PUNLMP exhibiting an inverted growth had no recurrence or progression on follow-up.

CONCLUSION

In this study, primary PUNLMP recurred primarily either as PUNLMP or low grade urothelial carcinoma. Primary PUNLMP rarely progressed to high grade or invasive carcinoma on long term follow-up. No recurrence or progression was documented on follow-up for PUNLMP that demonstrated exclusively inverted growth.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1332825572154074.

Prognostic factors in urothelial carcinoma of the bladder: histologic and molecular correlates

Histologic characterization of urothelial carcinoma remains the most important factor for determining a patient's prognosis and treatment regimen. However, challenges remain in accurately staging and grading many tumors, and substaging remains controversial. Recently, significant insight has been gained into the molecular pathogenesis of bladder cancer that may aid in further characterizing urothelial carcinoma. Many molecular biomarkers have been clinically validated, and some have been shown to provide more prognostic information than histology alone. In addition, a subset of these markers may even represent targets for molecular therapy. Here, we review histologic staging and grading of urothelial carcinoma, as well as discuss many of the clinically relevant molecular markers. As each urothelial carcinoma likely represents a unique biological entity, the need for complete histologic and molecular characterization of these tumors is necessary as we enter the age of personalized medicine.

Genetic variations rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population

Genome-wide association studies (GWAS) have identified a number of genetic variants associated with risk of bladder cancer in populations of European descent. Here, we assessed association of two of these variants, rs11892031 (2q37.1 region) and rs401681 (5p15.33 region) in a Chinese case-control study, which included 367 bladder cancer cases and 420 controls. We found that the AC genotype of rs11892031 was associated with remarkably decreased risk of bladder cancer (adjusted odds ratio (OR), 0.27; 95% confidence interval (CI), 0.09–0.81; p = 0.019), compared with the AA genotype of rs11892031; and that CT/CC genotypes of rs401681 were associated with significantly increased risk of bladder cancer (adjusted OR, 1.79; 95% CI, 1.10–2.91; p = 0.02), compared with the TT genotype of rs401681. We further conducted stratification analysis to examine the correlation between single nucleotide polymorphism (SNP) rs11892031/rs401681 and tumor grade/stage. Results showed that heterogeneity in ORs of tumor categories was not significant for either rs11892031 or rs401681 (p > 0.05), indicating that the two SNPs seemingly do not associate with tumor grade and stage of bladder cancer in our study population. The present study suggests that the SNPs rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population. Future analyses will be conducted with more participants recruited in a case-control study.

A Rare Case of Papillary Bladder Neoplasm Detected by Sonography in a Young Male

Bladder tumors are extremely rare in young adults and are usually linked to tobacco abuse, chronic infections, or occupational exposure to carcinogens. We present a case of a papillary urothelial neoplasm in a 19-year-old man with no significant risk factors, initially detected by sonography and later confirmed with computed tomographic urography and cystoscopy. The tumor was quickly resected and mitomycin C instilled in the bladder prophylactically. This is an atypical situation in a patient with none of the common risk factors.