Canine Transitional Cell Carcinoma

Genome-wide analyses reveals an association between invasive urothelial carcinoma in the Shetland sheepdog and NIPAL1

Naturally occurring canine invasive urinary carcinoma (iUC) closely resembles human muscle invasive bladder cancer in terms of histopathology, metastases, response to therapy, and low survival rate. The heterogeneous nature of the disease has led to the association of large numbers of risk loci in humans, however most are of small effect. There exists a need for new and accurate animal models of invasive bladder cancer. In dogs, distinct breeds show markedly different rates of iUC, thus presenting an opportunity to identify additional risk factors and overcome the locus heterogeneity encountered in human mapping studies. In the association study presented here, inclusive of 100 Shetland sheepdogs and 58 dogs of other breeds, we identify a homozygous protein altering point mutation within the NIPAL1 gene which increases risk by eight-fold (OR = 8.42, CI = 3.12-22.71), accounting for nearly 30% of iUC risk in the Shetland sheepdog. Inclusion of six additional loci accounts for most of the disease risk in the breed and explains nearly 75% of the phenotypes in this study. When combined with sequence data from tumors, we show that variation in the MAPK signaling pathway is an overarching cause of iUC susceptibility in dogs.

Clinical Use of Molecular Biomarkers in Canine and Feline Oncology: Current and Future

Molecular biomarkers are central to personalised medicine for human cancer patients. It is gaining traction as part of standard veterinary clinical practice for dogs and cats with cancer. Molecular biomarkers can be somatic or germline genomic alterations and can be ascertained from tissues or body fluids using various techniques. This review discusses how these genomic alterations can be determined and the findings used in clinical settings as diagnostic, prognostic, predictive, and screening biomarkers. We showcase the somatic and germline genomic alterations currently available to date for testing dogs and cats in a clinical setting, discussing their utility in each biomarker class. We also look at some emerging molecular biomarkers that are promising for clinical use. Finally, we discuss the hurdles that need to be overcome in going 'bench to bedside', i.e., the translation from discovery of genomic alterations to adoption by veterinary clinicians. As we understand more of the genomics underlying canine and feline tumours, molecular biomarkers will undoubtedly become a mainstay in delivering precision veterinary care to dogs and cats with cancer.

Feasibility of laparoscopic stapled partial cystectomy in canine cadavers

OBJECTIVE

To describe a technique for laparoscopic partial cystectomy and evaluate sealing of canine urinary bladder tissue with an endoscopic stapler.

STUDY DESIGN

Prospective, cadaveric study.

SAMPLE POPULATION

Eleven canine cadavers.

METHODS

Laparoscopic partial cystectomy was performed with an endoscopic gastrointestinal anastomosis (GIA) stapler. Leak testing and urodynamic evaluation was performed to measure intravesical pressure at initial leakage and catastrophic failure or the maximum pressure at which intravesical pressure plateaued. Surgical time, complications, and site of leakage were also recorded.

RESULTS

Laparoscopic partial cystectomy was successfully performed in 10 of 11 cadavers. Median procedure time was 13.6 min (10.1-15.2 min). Median intravesical pressure at initial leakage was 31 mmHg (28-56 mmHg) with a median increase from initial pressure of 15 mmHg (11-37 mmHg). No catastrophic failure of the cystectomy site was observed during leak testing. Intravesical pressure plateaued at a median of 52 mmHg (39-73 mmHg), which was a median of 13 mmHg (8-23 mmHg) higher than intravesical pressure at initial leakage. The median total volume infused at the time of plateau of intravesical pressure was 89 mL (58-133 mL).

CONCLUSION

Laparoscopic stapled partial cystectomy was feasible in canine cadavers. Endoscopic GIA staplers appear to seal the canine urinary bladder with minimal leakage.

CLINICAL SIGNIFICANCE

Use of an endoscopic GIA stapler may provide a minimally invasive option for partial cystectomy in dogs. Further evaluation for application to clinical cases is warranted.

Reason for euthanasia in dogs with urothelial carcinoma treated with chemotherapy or radiation therapy or both: A retrospective observational study

BACKGROUND

Clients want to know the ultimate cause of death in their pet after cancer treatment. The cause of euthanasia and investigation of urinary obstruction in treated dogs with urothelial carcinoma (UC) has not been specifically reported in veterinary literature.

HYPOTHESIS/OBJECTIVES

Our hypothesis was that the majority of treated dogs with UC are euthanized secondary to primary tumor factors, such as urinary obstruction.

ANIMALS

Fifty-nine client-owned dogs diagnosed with UC.

METHODS

Retrospective observational study on clinical signs and disease at euthanasia of dogs with UC treated by radiation therapy or chemotherapy or both.

RESULTS

The median overall survival time (OST) of all dogs was 339 days (range, 17-1996; 95% confidence interval [CI], 185-392; interquartile range [IQR], 112-505). Of dogs deemed to have been euthanized because of UC (50/59, 85%), the primary cause was considered to be local progression in 31/50 (62%), most often because of perceived complete or partial urinary obstruction (24/31, 77%). No variables were found to be predictive of urinary obstruction. The overall documented metastatic rate was 56%. In dogs euthanized because of UC, metastasis was deemed to be the cause in 19/50 (38%) dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Regardless of the type of treatment, UC in dogs has a poor prognosis and there is a continuing need to improve treatments that focus on local control of the primary tumor, given its high contribution to the decision for euthanasia. Proactive management to avoid the high frequency of urinary obstruction may be worthy of future investigation.

In vivo exposure of the bladder using a non-invasive high intensity focused ultrasound toroidal transducer

A toroidal high-intensity focused ultrasound (HIFU) transducer was used to expose normal bladder wall tissues non-invasively in vivo in a porcine model in order to investigate the potential to treat bladder tumors. The transducer was divided into 32 concentric rings with equal surface areas, operating at 2.5 MHz. Eight animals were split into two groups of 4. In the first group, post-mortem evaluation was performed immediately after ultrasound exposure. In the second group, animals survived for up to seven days before post-mortem evaluation. The ultrasound imaging guided HIFU device was hand-held during the procedure using optical tracking to ensure correct targeting. One thermal lesion in each animal was created using a 40 s exposure at 80 acoustic Watts (free-field) in the trigone region of the bladder wall. The average (±Standard Deviation) abdominal wall and bladder wall thicknesses were 10.3 ± 1.4 mm and 1.1 ± 0.4 mm respectively. The longest and shortest axes of the HIFU ablations were 7.7 ± 2.9 mm and 6.0 ± 1.8 mm, respectively, resulting in an ablation of the whole thickness of the bladder wall in most cases. Ablation were performed at an average depth (distance from the skin surface to the centre of the HIFU lesion) of 42.5 ± 3.8 mm and extended throughout the thickness of the bladder. There were two cases of injury to tissues immediately adjacent to the bladder wall but without signs of perforation, as confirmed by histological analysis. Non-invasive HIFU ablation using a hand-held toroidal transducer was successfully performed to destroy regions of the bladder wall in vivo.

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.

Association between cigarette smoke exposure and urinary bladder cancer in Scottish terriers in a cohort study

Canine urothelial carcinoma (UC) initially responds favorably to treatment, but is ultimately lethal in most cases. Research to identify modifiable risk factors to prevent the cancer is essential. The high breed-associated risk for UC, e.g. 20-fold higher in Scottish terriers, can facilitate this research. The objective was to identify environmental and host factors associated with UC in a cohort of Scottish terriers. Information was obtained through dog owner questionnaires for 120 Scottish terriers ≥ 6 years old participating in a bladder cancer screening study, with comparisons made between dogs that did or did not develop UC during the 3 years of screening. Univariable models were constructed, and variables with P < 0.20 were included when building the multivariable model, and then removed using a backward stepwise procedure. P < 0.05 was considered statistically significant. Urine cotinine concentrations were measured by liquid chromatography-mass spectrometry to further investigate potential cigarette smoke exposure. Biopsy-confirmed UC which was found in 32 of 120 dogs, was significantly associated with the dogs living in a household with cigarette smokers (odds ratio [OR], 6.34; 95 % confidence intervals [CI], 1.16-34.69; P = 0.033), living within a mile of a marsh or wetland (OR, 21.23; 95 % CI, 3.64-123.69; P = 0.001), and history of previous bladder infections (OR, 3.87; 95 % CI, 1.0-14.98; P = 0.050). UC was diagnosed in 18 of 51 dogs (35.3 %) with quantifiable cotinine concentrations, and six of 40 dogs (15.0 %) without quantifiable cotinine concentrations in their urine (P = 0.0165). In conclusion, the main modifiable risk factor for UC in this cohort of dogs was exposure to second-hand tobacco smoke.

Canine urothelial carcinoma: a pilot study of microRNA detection in formalin-fixed, paraffin-embedded tissue samples and in normal urine

We assessed the effects of fixation time in formalin and inclusion of surrounding tissue on microRNA (miRNA) cycle quantification (Cq) values in formalin-fixed, paraffin-embedded (FFPE) urothelial carcinoma (UC) tissue (n = 3), and the effect of conditions on miRNAs in urine from 1 healthy dog. MiRNAs were extracted using commercial kits and quantified using miRNA-specific fluorometry in normal bladder tissue scrolls, UC tissue cores, and bladder muscularis tissue cores from 4 FFPE bladder sections (3 UCs, 1 normal), plus 1 UC stored in formalin for 1, 8, 15, and 22 d before paraffin-embedding. Urine was collected from a healthy dog on 4 occasions; 1-mL aliquots were stored at 20, 4, -20, and -80°C for 4, 8, 24, and 48 h, and 1 and 2 wk. For both FFPE tissue and urine, we used reverse-transcription quantitative real-time PCR (RT-qPCR) to quantify miR-143, miR-152, miR-181a, miR-214, miR-1842, and RNU6B in each tissue or sample, using miR-39 as an exogenous control gene. The Cq values were compared with ANOVA and t-tests. The time of tissue-fixation in formalin did not alter miRNA Cq values; inclusion of the muscularis layer resulted in a statistically different miRNA Cq profile for miR-152, miR-181a, and RNU6B in bladder tissue. MiRNAs in acellular urine were stable for up to 2 wk regardless of the storage temperature. Our findings support using stored FFPE and urine samples for miRNA detection; we recommend measuring miRNA only in the tissue of interest in FFPE sections.

Pets, Genuine Tools of Environmental Pollutant Detection

In a shared environment, our companion animals became unintended sentinels for pollutant exposure consequences, developing even earlier similar conditions to humans. This review focused on the human-pet cohabitation in an environment we all share. Alongside other species, canine and feline companions are veritable models in human medical research. The latency period for showing chronic exposure effects to pollutants is just a few years in them, compared to considerably more, decades in humans. Comparing the serum values of people and their companion animals can, for example, indicate the degree of poisonous lead load we are exposed to and of other substances as well. We can find 2.4 times higher perfluorochemicals from stain- and grease-proof coatings in canine companions, 23 times higher values of flame retardants in cats, and 5 times more mercury compared to the average levels tested in humans. All these represent early warning signals. Taking these into account, together with the animal welfare orientation of today's society, finding non-invasive methods to detect the degree of environmental pollution in our animals becomes paramount, alongside the need to raise awareness of the risks carried by certain chemicals we knowingly use.

A Systematic Review of Canine Cystectomy: Indications, Techniques, and Outcomes

This review provides a summary of the literature encompassing partial and total cystectomy procedures in dogs and subsequent conclusions that can be drawn. Surgical excision as a component of treatment for lower urinary tract neoplasia in dogs may enhance survival time and result in acceptable quality of life, though risk for surgical complications is substantial, particularly following total cystectomy procedures. However, for dogs with urothelial carcinoma, cystectomy is generally not considered curative and disease progression is common. Appropriate case selection and thorough preoperative discussion with owners regarding potential risks and benefits of cystectomy are imperative for successful outcomes.

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.

Establishment and characterization of urothelial carcinoma cell lines with and without BRAF mutation (V595E) in dogs

Each 5 urothelial carcinoma (UC) cell lines with and without the v-Raf murine sarcoma virus oncogene homolog B (BRAF) gene mutation (V595E) were established and examined V595E-related tumorigenic characteristics in dogs. No typical morphological features were observed in cloned cells with and without V595E. The cell proliferation of both cloned cells showed logarithmic growth curve and those doubling time were 24.9 ± 4.1 h in V595E ( +) and 29.3 ± 11.3 h in V595E ( -). On the growth curve of xenotransplanted tumor in severe combined immunodeficiency mice, 3 out of 5 V595E ( +) and 2 out of 5 V595E ( -) cloned cells revealed gradually and remarkably increasing curve, indicating clearly tumorigenicity. The xenotransplanted tumors with V595E ( +) showed typical features of UC, such as solid proliferation of pleomorphic tumor cells, formation of papillary structure, and glandular structure. Additionally, various vascular formation was observed, probably indicating an advanced growth phase of UC. In mitogen-activated protein kinase (MAPK) signaling pathway, cytoplasmic phosphorylated-BRAF (pBRAF) and cytoplasmic and nuclear phosphorylated-ERK1/2 (pERK1/2) were detected in all 4 tumors with V595E ( +), whereas only cytoplasmic and nuclear pERK1/2 was detected in tumors with V595E ( -). Since V595E can directly activate MAPK signaling pathway, coincidence of V595E with pBRAF (phosphor Thr598/Ser601) indicates acquired resistance to BRAF inhibitors. These established UC cell lines, especially V595E ( +) cell lines, are useful tool for understanding pathophysiological states and controlling therapeutic manners of UC in dogs.

Tissue S100/calgranulin expression and blood neutrophil-to-lymphocyte ratio (NLR) in dogs with lower urinary tract urothelial carcinoma

BACKGROUND

Urothelial carcinoma (UC) is the most common neoplasm of the canine lower urinary tract, affecting approximately 2% of dogs. Elderly female patients of certain breeds are predisposed, and clinical signs of UC can easily be confused with urinary tract infection or urolithiasis. Diagnosis and treatment are challenging given the lack of disease-specific markers and treatments. The S100A8/A9 complex and S100A12 protein are Ca²⁺-binding proteins expressed by cells of the innate immune system and have shown promise as urinary screening markers for UC. The neutrophil-to-lymphocyte ratio (NLR) can also aid in distinguishing certain neoplastic from inflammatory conditions. Our study aimed to evaluate the tissue expression of S100/calgranulins and the blood NLR in dogs with UC. Urinary bladder and/or urethral tissue samples from dogs with UC (n = 10), non-neoplastic inflammatory lesions (NNUTD; n = 6), and no histologic changes (n = 11) were evaluated using immunohistochemistry. Blood NLRs were analyzed in dogs with UC (n = 22) or NNUTD (n = 26).

RESULTS

Tissue S100A12-positive cell counts were significantly higher in dogs with lower urinary tract disease than healthy controls (P = 0.0267 for UC, P = 0.0049 for NNUTD), with no significant difference between UC and NNUTD patients. Tissue S100A8/A9-positivity appeared to be higher with NNUTD than UC, but this difference did not reach statistical significance. The S100A8/A9⁺-to-S100A12⁺ ratio was significantly decreased in neoplastic and inflamed lower urinary tract tissue compared to histologically normal specimens (P = 0.0062 for UC, P = 0.0030 for NNUTD). NLRs were significantly higher in dogs with UC than in dogs with NNUTD, and a cut-off NLR of ≤ 2.83 distinguished UC from NNUTD with 41% sensitivity and 100% specificity. Higher NLRs were also associated with a poor overall survival time (P = 0.0417).

CONCLUSIONS

These results confirm that the S100/calgranulins play a role in the immune response to inflammatory and neoplastic lower urinary tract diseases in dogs, but the tissue expression of these proteins appears to differ from their concentrations reported in urine samples. Further investigations of the S100/calgranulin pathways in UC and their potential as diagnostic or prognostic tools and potential therapeutic targets are warranted. The NLR as a routinely available marker might be a useful surrogate to distinguish UC from inflammatory conditions.

Comparative Evaluation of Tumor-Infiltrating Lymphocytes in Companion Animals: Immuno-Oncology as a Relevant Translational Model for Cancer Therapy

Simple Summary

Laboratory experiments studying solid tumors are limited by the inability to adequately model the tumor microenvironment and important immune interactions. Immune cells that infiltrate the tumor bed or periphery have been documented as reliable biomarkers in human studies. Veterinary oncology provides a naturally occurring cancer model that could complement biomarker discovery, clinical trials, and drug development.

Abstract

Despite the important role of preclinical experiments to characterize tumor biology and molecular pathways, there are ongoing challenges to model the tumor microenvironment, specifically the dynamic interactions between tumor cells and immune infiltrates. Comprehensive models of host-tumor immune interactions will enhance the development of emerging treatment strategies, such as immunotherapies. Although in vitro and murine models are important for the early modelling of cancer and treatment-response mechanisms, comparative research studies involving veterinary oncology may bridge the translational pathway to human studies. The natural progression of several malignancies in animals exhibits similar pathogenesis to human cancers, and previous studies have shown a relevant and evaluable immune system. Veterinary oncologists working alongside oncologists and cancer researchers have the potential to advance discovery. Understanding the host-tumor-immune interactions can accelerate drug and biomarker discovery in a clinically relevant setting. This review presents discoveries in comparative immuno-oncology and implications to cancer therapy.

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.

Establishment of an experimental model of normal dog bladder organoid using a three-dimensional culture method

Dog bladder cancer (BC) is mostly muscle-invasive (MI) with poor prognosis, and its pathogenesis is close to human MIBC. Three-dimensional (3D) organoid culture ensures novel knowledge on cancer diseases including BC. Recently, we have established dog BC organoids (BCO) using their urine samples. BCO recapitulated the epithelial structures, characteristics, and drug sensitivity of BC-diseased dogs. However, organoids from dog normal bladder epithelium are not established yet. Therefore, the present study aimed to establish dog normal bladder organoids (NBO) for further understanding the pathogenesis of dog BC and human MIBC. The established NBO underwent various analyzes including cell marker expressions, histopathological structures, cancer-related gene expression patterns, and drug sensitivity. NBO could be produced non-invasively with a continuous culturing and recapitulated the structures and characteristics of the dog's normal bladder mucosal tissues. Different drug sensitivities were observed in each NBO. The analysis of RNA sequencing revealed that several novel genes were changed in NBO compared with BCO. NBO showed a higher expression of p53 and E-cadherin, but a lower expression of MDM2 and Twist1 compared with BCO. These results suggest that NBO could be a promising experimental 3D model for studying the developmental mechanisms of dog BC and human MIBC.

Extracellular vimentin mimics VEGF and is a target for anti-angiogenic immunotherapy

Anti-angiogenic cancer therapies possess immune-stimulatory properties by counteracting pro-angiogenic molecular mechanisms. We report that tumor endothelial cells ubiquitously overexpress and secrete the intermediate filament protein vimentin through type III unconventional secretion mechanisms. Extracellular vimentin is pro-angiogenic and functionally mimics VEGF action, while concomitantly acting as inhibitor of leukocyte-endothelial interactions. Antibody targeting of extracellular vimentin shows inhibition of angiogenesis in vitro and in vivo. Effective and safe inhibition of angiogenesis and tumor growth in several preclinical and clinical studies is demonstrated using a vaccination strategy against extracellular vimentin. Targeting vimentin induces a pro-inflammatory condition in the tumor, exemplified by induction of the endothelial adhesion molecule ICAM1, suppression of PD-L1, and altered immune cell profiles. Our findings show that extracellular vimentin contributes to immune suppression and functions as a vascular immune checkpoint molecule. Targeting of extracellular vimentin presents therefore an anti-angiogenic immunotherapy strategy against cancer.

The pro-tumorigenic effects of vimentin have been attributed to intracellular functions in tumour cells so far. Here, the authors show that tumour endothelial cells can secrete vimentin as a pro-angiogenic factor and that targeting of vimentin can be used as an immunotherapeutic strategy.

Characterizing the molecular and immune landscape of canine bladder cancer

Transitional cell carcinoma (TCC), also known as urothelial carcinoma, is the most common bladder cancer in humans and dogs. Approximately one-quarter of human TCCs are muscle-invasive and associated with a high risk of death from metastasis. Canine TCC (cTCC) tumours are typically high-grade and muscle-invasive. Shared similarities in risk factors, histopathology, and clinical presentation suggest that cTCC may serve as a model for the assessment of novel therapeutics that may inform therapies for human muscle-invasive TCC. The goal of this study was to characterize cTCC at the molecular level to identify drivers of oncogenesis and druggable targets. We performed whole exome sequencing (WES) of 11 cTCC tumours and three matched normal samples, identifying 583 variants in protein-coding genes. The most common variant was a V-to-E missense mutation in BRAF, identified in 4 out of 11 samples (36%) via WES. Sanger sequencing identified BRAF variants in 8 out of the same 11 cTCC samples, as well as in 22 out of 32 formalin-fixed paraffin embedded (FFPE) cTCC samples, suggesting an overall prevalence of 70%. RNA-Seq was performed to compare the gene expression profiles of cTCC tumours to normal bladder tissue. cTCC tumours exhibited up-regulation of genes involved in the cell cycle, DNA repair, and antiviral immunity. We also analysed the immune landscape of cTCC using immune gene signatures and immunohistochemical analysis. A subset of tumours had characteristics of a hot tumour microenvironment and exhibited high expression of signatures associated with complete response to PD-1/PD-L1 blockade in human 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.

Characteristics and Applications of Canine In Vitro Models of Bladder Cancer in Veterinary Medicine: An Up-to-Date Mini Review

Simple Summary

Bladder cancer (BC) in dogs is often lethal at the time of diagnosis. Therefore, there is a constant need for novel research on improvements of its characterization and treatment. Due to high cost and limited number of available dog patients, in vitro models of canine BC have been increasingly used for the last 25 years. In the present article, we present existing in vitro models of canine BC, including available simple (two-dimensional) and more complex (three-dimensional) models.

Abstract

Bladder cancer (BC) constitutes approximately 2% of all spontaneously occurring cancers in dogs. It is characterized by a devastating clinical course in most cases, which emphasizes a constant need for the development of novel methods of disease characterization and treatment. Over the past years, advances in cell engineering have resulted in the development of various canine in vitro models of BC, emerging as complements for in vivo research. In this article, we aimed to review the available data on existing in vitro models of canine BC, focusing primarily on their characteristics, applications in veterinary medicine, as well as advantages and disadvantages. The most commonly used in vitro models of canine BC comprise immortalized cell lines grown as adherent monolayers. They provide an unlimited supply of research material, however, they do not faithfully reflect the conditions prevailing in vivo, since the spatial cellular interactions are lost. The importance of the three-dimensional (3D) features of solid tumors in relation to carcinogenesis or drug response process has resulted in the development of the first canine 3D models of BC available for in vitro research. So far, results obtained with in vitro and in vivo research should be interpreted together. With the constantly growing complexity of in vitro models of BC cancer, animal-based research might be reduced in the future.

Fall time may be a reliable discriminator between neoplastic and non-neoplastic urinary bladder lesions in dogs undergoing contrast-enhanced ultrasound: a pilot study

Contrast-enhanced ultrasound (CEUS) can provide quantitative information on enhancement patterns and perfusion of lesions, based on time-intensity curves (TICs). No published studies have compared CEUS parameters in neoplastic and non-neoplastic urinary bladder lesions in dogs. The aim of the current prospective, pilot study was to quantitatively characterize the CEUS pattern of neoplastic and non-neoplastic urinary bladder lesions in dogs, assessing the influence of contrast arrival time (CAT) on the final appearance of the curves. Fourteen dogs with cyto-histopathological diagnoses were included (seven malignant and seven inflammatory lesions). B-mode ultrasound was performed followed by CEUS examination after an intravenous bolus injection of 0.04 mL/kg of contrast medium, and TICs were elaborated by dedicated software. Receiver operating characteristic curves (ROC) for each TIC parameter were obtained. Neoplastic lesions had subjectively shorter rise time (RT), time to peak (TTP) and fall time (FT) than inflammatory lesions. Based on ROC curve analyses, fall time ≥ 10.49 s was the most reliable parameter for diagnosing non-neoplastic disease in this small sample of dogs (area under the curve [AUC] 0.75, sensitivity 83.33%, specificity 66.67%). No difference was found between ROCs calculated for each parameter of TICs by adding or removing CAT. Results of the current study provide background for future, larger scale studies evaluating use of a CEUS FT threshold of 10.49 s as a possible discriminator for urinary bladder neoplastic lesions in dogs.

Evaluation of PD-1 and PD-L1 expression in canine urothelial carcinoma cell lines

Urothelial carcinoma (UC) is the most common urinary tumor in dogs and despite combinational therapies, only modest improvements in survival have been achieved in recent years. Given the utility of monoclonal antibodies against PD-1 and PD-L1 in human UC, we evaluated the protein and mRNA expression in three established canine urothelial carcinoma cell lines. Flow cytometry and western blot analysis confirmed cell line expression of both molecules in varying degrees. Reverse transcription PCR (RT-PCR) documented mRNA expression in all three cell lines for both PD-1 and PD-L1. Fluorescence microscopy was consistent with strong PD-1 and PD-L1 expression in the canine cell lines and was in line with previous human literature. Importantly, the flow cytometry work described in this study revealed higher cell intrinsic PD-1 expression in these cell lines which may have implications for tumor behavior and potential treatment opportunities in the future. Further work is necessary to determine the expression patterns in canine UC and potential for benefit with immunotherapy directed against PD-1 and PD-L1.

BRAF mutation status and its prognostic significance in 79 canine urothelial carcinomas: A retrospective study (2006-2019)

Urothelial carcinoma (UC) is the most common tumour of the canine urinary bladder. Recently, BRAF mutation testing emerged as a diagnostic option, but its prognostic significance is unknown. This study investigates the relationship between BRAF (variant V595E) mutation status and overall survival in UC-bearing dogs. Seventy-nine patients histologically diagnosed with UC of the bladder and/or urethra between 2006 and 2019 were included in this retrospective single-centre-study. Treatment consisted of meloxicam (n = 39, group 1 'Melox'), mitoxantrone and meloxicam (+/- followed by metronomic chlorambucil; n = 23, group 2 'Chemo') or partial cystectomy followed by meloxicam +/- mitoxantrone (n = 17, group 3 'Sx'). Survival was significantly influenced by treatment (p = .0002) and tumour location (p < .001) in both uni- and multivariable analyses. BRAF mutation was identified in 51 tumours (=64.6%) and had no statistically significant influence on overall survival: MST for BRAF-negative patients 359 versus 214 days for BRAF-positive dogs (p = .055). However, in BRAF-positive dogs, survival depended significantly on type of treatment in univariable analysis: MSTs for groups 1-3 were 151, 244 and 853 days, respectively (p = .006); In BRAF-positive group 2 ('Chemo')-patients, adjuvant metronomic chlorambucil after mitoxantrone more than doubled MST compared to patients receiving mitoxantrone alone (588 vs. 216 days; p = .030). In contrast, MSTs were not significantly different in BRAF-negative patients among the three treatment groups (p = .069). Multivariate analysis of these data was not possible due to group size limitations. This study identified tumour location and treatment type, but not BRAF mutation status, as independent prognostic factors for overall survival.

Evaluation of lymphocyte-specific programmed cell death protein 1 receptor expression and cytokines in blood and urine in canine urothelial carcinoma patients

Urothelial carcinoma (UC) is the most common urinary tumour in dogs. Despite a range of treatment options, prognosis remains poor in dogs. In people, breakthroughs with checkpoint inhibitors have established new standards of care for muscle-invasive bladder cancer patients and elevated levels of programmed cell death protein 1 (PD-1) suggest immune checkpoint blockade may be a novel target for therapy. The goal of this study was to determine if canine UC patients express elevated levels of lymphocyte-specific PD-1 and/or urinary cytokine biomarkers compared to healthy dogs. Paired blood and urine were evaluated in 10 canine UC patients, five cystitis patients and 10 control dogs for lymphocyte-specific PD-1 expression via flow cytometry and relative cytokine expression. In UC patients, PD-1 expression was significantly elevated on CD8⁺ lymphocytes in urine samples. UC patients had a higher CD4:CD8 ratio in their urine compared to healthy dogs, however, there was no significant variation in the CD8:Treg ratio between any group. Cystitis patients had significantly elevated levels of CD4⁺ T cells, CD8⁺ T cells and Tregs in their blood samples compared to UC patients and healthy dogs. Cytokine analysis demonstrated significant elevations in urinary cytokines (granulocyte-macrophage colony-stimulating factor, interferon-gamma [IFN-γ], interleukin (IL)-2, IL-6 IL-7, IL-8 and IL-15, IP-10, KC-like, IL-18, monocyte chemoattractant protein-1 and tumour necrosis factor-alpha). Several of these cytokines have been previously correlated with both lymphocyte-specific PD-1 expression (IFN-γ, IL-2, IL-7 and IL-15) in muscle-invasive urothelial carcinoma in humans. Our results provide evidence of urinary lymphocyte PD-1 expression and future studies could elucidate whether veterinary UC patients will respond favourably to anti-PD-1 immune checkpoint inhibitor therapy.

Case report laparoscopy-assisted pre-pubic urethrostomy as a palliative procedure for resection of distal urethral tumor in a female dog

Background

This paper presents the first described case of laparoscopy-assisted prepubic urethrostomy and laparoscopic resection of a tumor of the distal part of the urethra in a female dog as a palliative treatment.

Case presentation

An intact, 11 -year-old, mixed breed female dog, weighing 15 kg, was admitted with signs of urinary obstruction and difficulty with catheterization. Vaginal, rectal, and endoscopic examinations revealed a firm mass in the pelvic cavity at the level of the pelvic urethra. Ultrasound and computed tomography examination showed enlargement of the urethral wall (5.5 cm width and 3 cm thick), which was significantly restricting the patency of the urethra. The lesion affected only the distal part of the urethra without the presence of local or distant metastatic changes.

The affected portion of the urethra was laparoscopically removed while performing pre-pubic urethrostomy with laparoscopy. The patient regained full consciousness immediately after the end of anesthesia, without signs of urinary incontinence. Histopathological examination of the removed urethra revealed an oncological margin only from the side of the bladder. In the period of 2.5 months after the procedure, the owner did not notice any symptoms that could indicate a postoperative recurrence, which was diagnosed three months after the procedure.

Conclusions

Pre-pubic urethrostomy can be successfully performed with the assistance of laparoscopy. The use of minimally invasive surgery will allow, in selected cases, removal of the urethral tumor, and in inoperable cases, to perform a minimally invasive palliative pre-pubic urethrostomy.

Hypertensive Cardiomyopathy as a Sequel to Hydronephrosis Induced by Transitional Cell Carcinoma

A 10-year-old female Griffon dog was presented for evaluation due to a 5-month history of hematuria and systemic hypertension. Thoracic auscultation detected a grade II/VI left apical systolic murmur. Abdominal ultrasound revealed the presence of a heterogeneous mass at the trigonal area of the urinary bladder, extending to the left ureter cranially and caudally toward the bladder's neck. Marked left hydronephrosis and hydroureter were detected as well as mild right hydronephrosis. Cytological examination of urine sediment confirmed the presence of transitional cell carcinoma. Echocardiography disclosed marked left ventricular concentric hypertrophy, which likely developed as a consequence of systemic hypertension induced by the bilateral hydronephrosis due to bladder transitional cell carcinoma.

Establishment of Canine Transitional Cell Carcinoma Cell Lines Harboring BRAF V595E Mutation as a Therapeutic Target

Transitional cell carcinoma (TCC) is the most common malignant tumor of the canine urinary tract and tends to have a poor prognosis due to its invasive potential. Recent studies have reported that up to 80% of canine urothelial carcinoma has the BRAF V595E mutation, which is homologous to the human V600E mutation. Activating the BRAF mutation is an actionable target for developing effective therapeutic agents inhibiting the BRAF/mitogen-activated protein kinase (MAPK) pathway in canine cancer as well as human cancer. We established novel canine TCC cell lines from two tumor tissues and one metastatic lymph node of canine TCC patients harboring the BRAF V595E mutation. Tumor tissues highly expressed the BRAF mutant and phosphorylated extracellular signal-related kinases (ERK)1/2 proteins. The derived cell lines demonstrated activated MAPK pathways. We also evaluated the cell lines for sensitivity to BRAF inhibitors. Sorafenib, a multiple kinase inhibitor targeting RAF/vascular endothelial growth factor receptor (VEGFR), successfully inhibited the BRAF/MAPK pathway and induced apoptosis. The established canine TCC cell lines responded with greater sensitivity to sorafenib than to vemurafenib, which is known as a specific BRAF inhibitor in human cancer. Our results demonstrated that canine TCC cells showed different responses compared to human cancer with the BRAF V600E mutation. These cell lines would be valuable research materials to develop therapeutic strategies for canine TCC patients.

Combination therapy with cannabidiol and chemotherapeutics in canine urothelial carcinoma cells

Background

Canine urothelial carcinoma is the most common form of canine bladder cancer. Treatment with chemotherapy has variable response rates leading to most dogs succumbing to their disease within a year. Cannabidiol is an emerging treatment within the field of oncology. In reported in vivo studies, cannabidiol has induced apoptosis, reduced cell migration, and acted as a chemotherapy sensitizer in various human tumor types. The aim of this study was to characterize the effects of cannabidiol on canine urothelial carcinoma cell viability and apoptosis as both a single agent and in combination with chemotherapy in vitro.

Results

Cannabidiol reduced cell viability and induced apoptosis in canine urothelial cells as determined by crystal violet viability assay and annexin V/propidium iodide flow cytometry. Furthermore, combinations of cannabidiol with mitoxantrone and vinblastine chemotherapy yielded significantly reduced cell viability and increased apoptosis compared to single agent treatment alone. The drug interactions were deemed synergistic based on combination index calculations. Conversely, the combination of cannabidiol and carboplatin did not result in decreased cell viability and increased apoptosis compared to single agent treatment. Combination index calculations suggested an antagonistic interaction between these drugs. Finally, the combination of the non-steroidal anti-inflammatory drug piroxicam with cannabidiol did not significantly affect cell viability, although, some cell lines demonstrated decreased cell viability when mitoxantrone was combined with piroxicam.

Conclusions

Cannabidiol showed promising results as a single agent or in combination with mitoxantrone and vinblastine for treatment of canine urothelial carcinoma cells. Further studies are justified to investigate whether these results are translatable in vivo.

Longitudinal assessment of B-RAF V595E levels in the peripheral cell-free tumor DNA of a 10-year-old spayed female Korean Jindo dog with unresectable metastatic urethral transitional cell carcinoma for monitoring the treatment response to a RAF inhibitor (sorafenib)

Transitional cell carcinoma (TCC) is the most common malignant tumor of the canine urinary tract. In this case study, a dog with metastatic urethral TCC was treated with sorafenib. The tumor expression levels of receptor tyrosine kinase genes, including VEGFR-1, VEGFR-2, PDGFR-α, PDGFR-β, ALK, EGFR, ErbB2, and B-RAF, were analyzed. VEGFR was overexpressed in tumor tissues compared to the normal tissues. Considering the high frequency of B-RAF mutation in canine urological tumors, the B-RAF gene was examined, and the B-RAF V595E mutation was detected in the tumor tissue. Therefore, the antitumor effect of sorafenib, a multi-tyrosine kinase inhibitor, on unresectable metastatic urethral TCC characterized by B-RAF V595E was evaluated and circulating cell-free tumor DNA (ctDNA) was assessed for monitoring the treatment response. After the initiation of oral sorafenib therapy (4 mg/kg/day escalated to 10 mg/kg/day), the dysuria was alleviated gradually, and the patient remained stable for 3 months. During that treatment period, the patient showed various levels of changes associated with B-RAF V595E mutation in ctDNA as evident from longitudinal plasma samples after initiation of sorafenib therapy. The findings of this study suggest that ctDNA may serve as a useful non-invasive tool for monitoring the treatment response to anticancer drugs.

Comparison of pathologist review protocols for cytologic detection of prostatic and urothelial carcinomas in canines: A bi-institutional retrospective study of 298 cases

Urothelial carcinoma, also known as transitional cell carcinoma, is the most common primary bladder tumour in dogs, and can also involve the prostate gland. Cytology is a common diagnostic tool utilized for dogs with bladder or prostate gland lesions. The objectives of this retrospective study were to compare the sensitivity and specificity of cytologic evaluation for urothelial or prostatic carcinoma between two institutions with different cytology review protocols as well as determine if certain collection methods resulted in higher cytologic accuracy. A total of 298 cases met inclusion criteria. The overall sensitivity and specificity for institution 1 were 91.8% and 50%, respectively, compared to 31.1% and 97.4%, respectively, for institution 2. When the urine sample review protocol at institution 2 was matched to that of institution 1, sensitivity and specificity were more similar to institution 1 (71.2% and 88.9%, respectively). Our results show that the sensitivity and specificity of cytology are affected by screening and review protocols implemented by different institutions. The data also demonstrate that sensitivity and specificity vary by collection method. Diagnostic catheterization had the highest performance: of the 11 cases between two institutions, it had 100% sensitivity and specificity. In contrast, examination of urine sediment not collected via diagnostic catheterization had low sensitivity and specificity that varied greatly by institution. In summary, cytologic interpretation should be undertaken with consideration given to both processing and collection protocols.

Creation of a Continent Urinary Bladder Reservoir Vascularized by Omentum as a Possible Surgical Option for Canine Trigonal/Urethral Urothelial Carcinoma

Surgical procedures that maintain continence with minimal complication following resection of trigono-urethral urothelial carcinoma (UC) are limited in canines; therefore, palliative options are often pursued. A feasible tumor resection option may improve disease control and survival. The study's objective was to evaluate a continent urine reservoir created from the urinary bladder body and vascularized solely by omentum. We hypothesized that a viable urine reservoir could be created, and staged omentalization would provide improved vascularity. Nine normal female Beagles were randomized to one of three groups. Group A urinary bladders were transected cranial to the ureteral papillae to create a closed bladder vesicle which was concomitantly omentalized. Group B underwent omentalization two weeks prior to vesicle creation. Based on Group A and B results, Group C underwent neoureterocystostomy and omentalization followed by neoreservoir formation and tube cystostomy 2 weeks later. Serial ultrasounds and histopathology confirmed adequate omental neovascularization in Groups B and C with continent Group C neoreservoirs maintained for 2 months. Some pylectasia and ureteral dilation was documented in all Group C dogs at variable timepoints. Progressive hydroureteronephrosis developed in 2/6 kidneys. Transient azotemia was noted in only 1 Group C dog, although all developed treatable urinary tract infections. The sample size is limited, and the efficacy of this technique in providing disease control for UC is unknown. However, this novel option could allow for primary UC resection while providing continence and limiting complications. Postoperative local or systemic adjuvant therapy, ultrasonographic neoreservoir monitoring, and BRAF analysis would be indicated.

Histological Characterization of Feline Bladder Urothelial Carcinoma

Urothelial (transitional cell) carcinoma (UC) is the most common type of bladder cancer in humans, dogs and cats, although the incidence in cats is comparatively low. This retrospective study details the histopathological features of UC of the urinary bladder in 38 samples from 35 cats. Of the 38 samples, eight had a papillary architecture and in nine the tumour cells formed tubular or acinar structures. Tumour cell invasion of the bladder wall varied from confinement within the lamina propria or submucosa to transmural or extending to the serosa. The tumour stroma varied from sparse to abundant, with a scirrhous, myxomatous or mucinous appearance in eleven cases, three cases and one case, respectively. The degrees of tumour cell necrosis and inflammation were highly variable. We confirm that the histopathological features of bladder UC in cats have many similarities to the corresponding tumours in dogs and humans.

Antitumor activity of an oncolytic measles virus against canine urinary bladder transitional cell carcinoma cells

The prognosis of canine transitional cell carcinoma (TCC) of urinary bladder is generally poor because it is difficult to diagnose at early stages and conventional therapies, such as surgical resection and/or chemotherapy, are often not curative treatments. Based on our previous report that recombinant measles virus (rMV-SLAMblind) therapy could be a new treatment for canine mammary tumor, the applicability of rMV-SLAMblind in canine urinary bladder TCC was examined in this study. A canine TCC cell line was established from a TCC patient dog by transplanting a piece of the tumor mass into an immunodeficient mouse and then isolating the primary TCC cells from the grown tumor mass. The primary cultured cells, named TCC-NU1, express nectin-4, a receptor for rMV-SLAMblind infection. The rMV-SLAMblind infected TCC-NU1 cells, and dose-dependently showed cell cytotoxicity. Moreover, intratumoral administration of rMV-SLAMblind in a xenograft model bearing TCC-NU1 cells significantly suppressed the tumor growth reducing the endpoint mass of tumors in treated mice compared to control mice. These results suggest that virotherapy with rMV-SLAMblind be a new candidate therapy for canine TCC.

BRAFV595E Mutation Associates CCL17 Expression and Regulatory T Cell Recruitment in Urothelial Carcinoma of Dogs

Regulatory T cells may serve as targets in cancer immunotherapy. A previous study showed that the chemokine CCL17 and the receptor CCR4 play roles in regulatory T cell recruitment in canine urothelial carcinoma. In this article, we show that the BRAF^V595E mutation is associated with tumor-produced CCL17 and regulatory T cell infiltration in dogs with urothelial carcinoma. In comparison with healthy dogs, dogs with urothelial carcinoma showed increased CCL17 mRNA expression in the bladder and elevated CCL17 protein concentration in urine. Immunohistochemistry showed increased levels of Foxp3⁺ regulatory T cells in the tumor tissues of urothelial carcinoma. The density of Foxp3⁺ regulatory T cells was positively correlated with CCL17 concentration in urine, indicating that CCL17 is involved in regulatory T cell recruitment. Moreover, tumor-infiltrating regulatory T cells and urine CCL17 concentration were associated with poor prognosis in dogs with urothelial carcinoma. The number of tumor-infiltrating regulatory T cells, CCL17 mRNA expression, and urine CCL17 concentration in cases with BRAF^V595E mutation were higher than those in cases with wild-type BRAF. In vitro, high CCL17 production was detected in a canine urothelial carcinoma cell line with BRAF^V595E mutation but not in an urothelial carcinoma cell line with wild-type BRAF. Dabrafenib, a BRAF inhibitor, decreased CCL17 production in the cell line with BRAF^V595E mutation. These results suggest that BRAF^V595E mutation induced CCL17 production and contributed to regulatory T cell recruitment in canine urothelial carcinoma.

Adjuvant doxorubicin vs metronomic cyclophosphamide and meloxicam vs surgery alone for cats with mammary carcinomas: A retrospective study of 137 cases

This study aims to evaluate the efficacy and side effects of low dose cyclophosphamide chemotherapy plus meloxicam as an adjuvant treatment, compared with high dose doxorubicin or surgery alone in cats with mammary carcinoma. Medical records of 228 female cats treated for mammary carcinoma between 2008 and 2018, were reviewed in eight veterinary institutions. Only cats with complete tumour staging and radical mastectomy were included in the study. One hundred and thirty-seven cats were divided into three treatment groups: group 1 (n = 80) cats treated with surgery, group 2 (n = 34) cats that had surgery and adjuvant treatment with doxorubicin, and group 3 (n = 23) cats with surgery and adjuvant treatment with low dose metronomic cyclophosphamide and meloxicam. The study endpoints were disease free interval (DFI) and overall survival (OS). Toxicity was evaluated according to the VCOG-CTCAE criteria. The median DFI was 270, 226 and 372 days in groups 1, 2 and 3, respectively. The median OS was 338 (group 1), 421 (group 2) and 430 (group 3) days. The differences between groups were not significant (DFI P = .280 and OS P = .186). Toxicity was observed in 52.9% (n = 18) of cats in group 2 and 39.1% (n = 9) of cats in group 3, with mild to moderate intensity. Differences were not significant (P = .306). In conclusion, adjuvant chemotherapy treatment did not improve survival and the overall benefit remains unproven. Randomized prospective trials are necessary to clarify the effectiveness of adjuvant chemotherapy treatment for feline mammary carcinomas.

A combined protocol with piroxicam, chemotherapy, and whole pelvic irradiation with simultaneous boost volumetric modulated arc radiotherapy for muscle-invasive canine urinary transitional cell carcinoma: First clinical experience

The aims of this pilot study were to evaluate the feasibility and efficacy of high-dose hypofractionated volumetric modulated arc radiotherapy (VMAT) applied to whole pelvic region radiotherapy (WPRT) with multilevel simultaneous integrated boost (MLSIB) combined with piroxicam and chemotherapy for the treatment of canine transitional cell carcinoma (TCC) of the lower urinary tract with muscle invasion TCC. Twelve dogs were enrolled, according to stage, in two groups: group 1, TCC confined to the urinary tract; group 2, TCC with metastasis. The planning target volume dose was tailored from 36 to 42 Gy in 6 fractions. All dogs were prescribed piroxicam and radiosensitizing carboplatin, and six received chemotherapy after radiotherapy. Serial follow-ups with computed tomography and magnetic resonance imaging were performed. Disease control and toxicity effects were evaluated according to the Response Evaluation Criteria in Solid Tumors and Veterinary Radiation Therapy Oncology Group criteria. The treatment was well tolerated, and no high-grade side effects were reported. The median overall survival times for groups 1 and 2 were 1,230 and 150 days, respectively. A considerable percentage of patients in group1 (50%) were still alive at the time of writing this paper, and a longer follow-up could enable a more accurate survival analysis. This preliminary analysis shows that VMAT applied to the WPRT with MLSIB is an effective and safe option for dogs with lower urinary TCC, although the presence of metastases worsens the prognosis.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model

OBJECTIVE

To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies.

STUDY DESIGN

Ex vivo, simple randomized study.

SAMPLE POPULATION

Urinary bladders harvested from canine cadavers (n = 23).

METHODS

Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies.

RESULTS

Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders.

CONCLUSION

Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure.

CLINICAL SIGNIFICANCE

This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Outcomes following balloon dilation for management of urethral obstruction secondary to urothelial carcinoma in dogs: 12 cases (2010-2015)

OBJECTIVE

To describe outcomes for dogs that underwent balloon dilation for palliative treatment of urethral obstruction caused by urothelial carcinoma.

ANIMALS

12 client-owned dogs.

PROCEDURES

Medical records were searched to identify dogs with urothelial (bladder, urethra, or prostate) carcinoma that underwent balloon dilation for treatment of urethral obstruction between April 2010 and December 2015. Information regarding history, signalment, clinical signs, diagnostic imaging findings, balloon dilation technique, clinical outcomes, complications, and additional treatments was obtained by review of medical records.

RESULTS

Improvement in clinical signs of urethral obstruction was observed after the initial dilation procedure for 9 of 12 dogs. Urethral obstruction was known to recur in 5 dogs 48 to 296 days after the initial procedure. Three of these dogs underwent a second dilation procedure, with clinical improvement in all 3 dogs for 41 to 70 days. One of 2 dogs that had a third procedure after the second reobstruction had clinical improvement in urinary tract signs until subsequent death from metastatic disease 22 days later. Complications included hematuria, urinary incontinence, and dysuria; these resolved within a few days after treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Urethral balloon dilation was a minimally invasive procedure that provided relief of urethral obstruction from urothelial carcinoma in most dogs of the study population. Prospective studies are needed to identify optimal techniques for balloon dilation in dogs with neoplastic urethral obstructions and to identify patients that are likely to benefit most from the treatment.

Evaluation of completeness of resection of the glandular portion of the uterus with hysterectomy in dogs - A pilot study

Gonadectomies are the most commonly performed surgical procedures in dogs. The benefits and risks associated with gonadectomy in dogs have been broadly investigated. Due to concerns associated with ovariectomy, some pet-owners and veterinarians are considering surgical alternatives which terminate the capacity for reproduction without removal of the gonads to preserve functions of the gonadal hormones. The objective of this study was to determine the feasibility of complete resection of the glandular portion of the uterus with hysterectomy (HE). Using a prospective cadaveric and an ex-vivo design, uterine resection was performed cranially and caudally to the cervix, and at the proper ligament to simulate routine ovariohysterectomy and HE. Using microscopic evaluation procedures, there was identification of glandular tissue at the surgical margin of all samples resected cranially to the cervix and no glandular tissue in the samples resected caudally to the cervix. Half of the samples from the uterine horns contained glandular tissue. The results of the present study indicate ligation and transection of the uterus caudally to the cervix (as recommended for HE) allows for complete resection of glandular tissues, however, transection at the proper ligament may not. The clinical relevance of retention of para-ovarian uterine glandular tissue is unknown. Additional research is needed where there is investigation of the consequences and surgical technique for HE before there is widespread clinical use of this procedure.

Establishment of 2.5D organoid culture model using 3D bladder cancer organoid culture

Three-dimensional (3D) organoid culture holds great promises in cancer precision medicine. However, Matrigel and stem cell-stimulating supplements are necessary for culturing 3D organoid cells. It costs a lot of money and consumes more time and effort compared with 2D cultured cells. Therefore, the establishment of cheaper and Matrigel-free organoid culture that can maintain the characteristics of a part of 3D organoids is demanded. In the previous study, we established a dog bladder cancer (BC) 3D organoid culture system by using their urine samples. Here, we successfully isolated cells named "2.5D organoid" from multiple strains of dog BC 3D organoids using 2.5 organoid media. The cell proliferation speed of 2.5D organoids was faster than parental 3D organoid cells. The expression pattern of stem cell markers was close to 3D organoids. Injection of 2.5D organoid cells into immunodeficient mice formed tumors and showed the histopathological characteristics of urothelial carcinoma similar to the injection of dog BC 3D organoids. The 2.5D organoids had a similar sensitivity profile for anti-cancer drug treatment to their parental 3D organoids. These data suggest that our established 2.5D organoid culture method might become a reasonable and useful tool instead of 3D organoids in dog BC research and therapy.

Outcomes associated with vaginectomy and vulvovaginectomy in 21 dogs

OBJECTIVE

To report the outcomes of dogs with lesions of the genitourinary tract treated by vaginectomy or vulvovaginectomy.

STUDY DESIGN

Multi-institutional retrospective study.

ANIMALS

Female dogs that underwent vulvovaginectomy, complete vaginectomy, or subtotal vaginectomy from 2003 to 2018 with complete medical records and a minimum of 60 days follow-up.

METHODS

Data collected from medical records included preoperative, intraoperative, and postoperative data, such as the occurrence of urinary incontinence (UIC), disease recurrence, and death/euthanasia.

RESULTS

This study included 21 dogs. Four dogs had vulvovaginectomy, six had complete vaginectomy, and 11 had a subtotal vaginectomy performed. The mean age at surgery was 9.2 years (SD, 3.3). Thirteen dogs were intact at presentation. Smooth muscle tumors were diagnosed most commonly (10 leiomyomata, three leiomyosarcomas, two leiomyofibromas). The median duration of follow-up was 520 days (range, 71-1955). Major complications requiring revision surgery were recorded in two dogs. Postoperative UIC occurred in six of 21 dogs, resolving spontaneously within 60 days in three dogs. Dogs with malignant tumors (n = 6) survived at least 71 days (median, 626; 95% CI, 71-1245), and recurrence of disease occurred in two dogs. In dogs with benign tumors (n = 15), the median survival time was not reached. These dogs survived at least 104 days and had no recurrence of the disease.

CONCLUSION

Vaginectomy and vulvovaginectomy resulted in prolonged survival and low rates of major complications and UIC.

CLINICAL SIGNIFICANCE

This study provides evidence to recommend that the risks of this procedure and expectations should be discussed with clients.

Successful Treatment of Urinary Bladder Hemangiosarcoma by Partial Cystectomy in a Dog

A 6 yr old neutered male German shepherd dog was evaluated at a veterinary referral hospital following diagnosis of uroabdomen of unknown origin. A positive-contrast retrograde urethrogram identified diffusely irregular margins of the urinary bladder but no active leakage of urine into the peritoneal cavity. An abdominal ultrasound identified severe thickening and loss of wall layering of the apex of the bladder. The dog was initially managed with an indwelling urinary catheter; however, when the catheter was removed 5 days later, the dog developed a recurrent uroabdomen after an episode of dysuria. Subsequent surgical exploration identified numerous (>5), small (1-2 cm), black cyst-like nodules within the bladder wall at the apex of the bladder. A partial cystectomy, removing approximately 65% of the cranial bladder, was performed. Histopathology and immunohistochemistry of the bladder identified hemangiosarcoma of the bladder wall with chronic neutrophilic and hemorrhagic cystitis. The dog recovered from surgery without major complication and is still alive 9 mo following surgery. To the authors' knowledge, this is the first report of successful treatment of canine bladder hemangiosarcoma by partial cystectomy in a dog.

Desexing Dogs: A Review of the Current Literature

Background: Desexing dogs is promoted for population control, preventative healthcare, and behavior modification. Common methods are orchiectomy and ovariectomy/ovariohysterectomy. GnRH superagonist implants are available in some areas. Alternative methods like vasectomy and salpingectomy/hysterectomy are uncommon. The terminology used to describe desexing is inconsistent and contradictory, showing a need for the adaption of standardized terminology. Population Control: Surprisingly, empirical studies show no effects of desexing on population control in companion and shelter dogs despite desexing being consistently recommended in the literature. There is evidence for a population control effect in free-roaming dogs, where desexing also has benefits on zoonotic disease and bite risk. Population control in free-roaming dogs is mostly correlated with female, not male desexing. Health and Lifespan: Desexing affects numerous disease risks, but studies commonly neglect age at diagnosis and overall lifespan, age being by far the most important risk factor for most diseases. We argue that lifespan is a more important outcome than ultimate cause of death. A beneficial effect of desexing on lifespan is consistently demonstrated in females, while evidence for a beneficial effect in males is inconsistent. Studies are likely biased in desexing being a proxy for better care and desexed dogs having already lived to the age of desexing. Desexing reduces or eliminates common life-limiting diseases of the female reproductive system such as pyometra and mammary tumors, while no analogous effect exists in males. Disease risks increases across sexes and breeds include cruciate ligament rupture, various cancers, and obesity. Urinary incontinence risk is increased in females only. Various other disease risk changes show considerable variability between breeds and sexes. Behavioral Effects: Desexed males show reduced libido, roaming, conspecific mounting, and urinary marking frequency, as well as reduced male dog-directed aggression in a majority of males desexed for behavioral reasons. There is a detrimental effect on the risk and progression of age-related cognitive dysfunction. Desexed dogs may be less likely to cause bite injuries across sexes. The evidence for other effects such as human-directed aggression, human or object mounting, resource guarding, or shyness and anxiety is inconsistent and contradictory. There are few studies specific to females or individual breeds. Conclusions: The evidence for a beneficial effect of desexing is stronger in female than in male dogs; however, there is significant variation between breeds and sexes, and more research is needed to further elucidate these differences and to arrive at individualized evidence-based recommendations for clinical practice.

Lower urinary tract transitional cell carcinoma in cats: Clinical findings, treatments, and outcomes in 118 cases

Background

Lower urinary tract transitional cell carcinoma (TCC) is an important but rarely described disease of cats.

Objectives

To report the clinical characteristics, treatments, and outcomes in a cohort of cats with lower urinary tract TCC and to test identified variables for prognostic relevance.

Animals

One‐hundred eighteen client‐owned cats with lower urinary tract carcinoma.

Methods

Medical records were retrospectively reviewed to obtain information regarding clinical characteristics, treatments, and outcomes. Recorded variables were analyzed statistically.

Results

Median age of affected cats was 15 years (range, 5.0‐20.8 years) and median duration of clinical signs was 30 days (range, 0‐730 days). The trigone was the most common tumor location (32/118; 27.1%) as assessed by ultrasound examination, cystoscopy, or both. Treatment was carried out in 73 of 118 (61.9%) cats. Metastatic disease was documented in 25 of 118 (21.2%) cats. Median progression‐free survival and survival time for all cats were 113 days (95% confidence interval [CI], 69‐153) and 155 days (95% CI, 110‐222), respectively. Survival increased significantly (P < .001) when comparing cats across the ordered treatment groups: no treatment, treatment without partial cystectomy, and treatment with partial cystectomy. Partial cystectomy (hazard ratio [HR], 0.31; 95% CI, 0.17‐0.87) and treatment with nonsteroidal anti‐inflammatory drugs (HR, 0.55; 95% CI, 0.33‐0.93) were significantly associated with longer survival times.

Conclusions and Clinical Importance

The results support treatment using partial cystectomy and NSAIDs in cats with TCC.

Establishment of a novel experimental model for muscle-invasive bladder cancer using a dog bladder cancer organoid culture

In human and dogs, bladder cancer (BC) is the most common neoplasm affecting the urinary tract. Dog BC resembles human muscle‐invasive BC in histopathological characteristics and gene expression profiles, and could be an important research model for this disease. Cancer patient‐derived organoid culture can recapitulate organ structures and maintains the gene expression profiles of original tumor tissues. In a previous study, we generated dog prostate cancer organoids using urine samples, however dog BC organoids had never been produced. Therefore we aimed to generate dog BC organoids using urine samples and check their histopathological characteristics, drug sensitivity, and gene expression profiles. Organoids from individual BC dogs were successfully generated, expressed urothelial cell markers (CK7, CK20, and UPK3A) and exhibited tumorigenesis in vivo. In a cell viability assay, the response to combined treatment with a range of anticancer drugs (cisplatin, vinblastine, gemcitabine or piroxicam) was markedly different in each BC organoid. In RNA‐sequencing analysis, expression levels of basal cell markers (CK5 and DSG3) and several novel genes (MMP28,CTSE,CNN3,TFPI2,COL17A1, and AGPAT4) were upregulated in BC organoids compared with normal bladder tissues or two‐dimensional (2D) BC cell lines. These established dog BC organoids might be a useful tool, not only to determine suitable chemotherapy for BC diseased dogs but also to identify novel biomarkers in human muscle‐invasive BC. In the present study, for the 1st time, dog BC organoids were generated and several specifically upregulated organoid genes were identified. Our data suggest that dog BC organoids might become a new tool to provide fresh insights into both dog BC therapy and diagnostic biomarkers.

Anti-tumor effects of the histone deacetylase inhibitor vorinostat on canine urothelial carcinoma cells

Canine urothelial carcinoma (cUC) is the most common tumor of the lower urinary tract in dogs. Although chemotherapy and radical surgery have improved the overall survival, most dogs with cUC succumb to metastasis or recurrence. Therefore, the development of an effective systematic therapy is warranted. In this study, a comprehensive drug screening test using a cUC cell line was performed and the anti-tumor effect of a histone deacetylase (HDAC) inhibitor was evaluated. Comprehensive drug screening was performed on cUC cells. Based on this screening, the anti-proliferation effect of vorinostat, an HDAC inhibitor clinically applied in humans, was evaluated using several cUC cell lines in sulforhodamine B and flow cytometry assays. Western blot analysis was also performed to evaluate the degree of acetylation of histone H3 as well as the expression and phosphorylation of cell cycle-related molecules. The anti-tumor effect of vorinostat in vivo was evaluated using a xenograft model. Finally, immunohistochemistry was performed on acetyl-histone H3 in cUC and the relationship between the degree of acetylation and prognosis was examined using Kaplan–Meier survival analysis. Drug screening revealed that HDAC inhibitors consistently inhibited the growth of cUC cells. Vorinostat inhibited the growth of 6 cUC cell lines in a dose-dependent manner and induced G0/G1 cell cycle arrest. Western blot analysis showed that vorinostat mediated the acetylation of histone H3, the dephosphorylation of p-Rb, and the upregulation of p21 upon exposure to vorinostat. Furthermore, inhibition of tumor growth was observed in the xenograft model. In clinical cUC cases, neoplastic urothelium showed significant deacetylation of histones compared to the normal control, where lower histone acetylation levels were associated with a poor prognosis. In conclusion, the therapeutic potential of vorinostat was demonstrated in cUC. Histone deacetylation may be related to cUC tumor progression.

Survival analysis in dogs with urinary transitional cell carcinoma that underwent whole-body computed tomography at diagnosis

This retrospective study aimed to evaluate factors associated with survival and to compare characteristics between tumour localizations in dogs with urinary transitional cell carcinoma (TCC) that underwent whole-body computed tomography (CT) at diagnosis. Dogs with histologically confirmed TCC that received medical therapy between 2010 and 2017 were included; dogs that underwent surgery or radiotherapy for the primary tumour were excluded. According to the CT findings, primary tumour localization (classified into the Bladder, Urethra and Bladder and Urethra groups), prostate involvement, iliosacral lymphadenomegaly, sternal lymphadenomegaly and metastasis to the bone and lung were evaluated for survival analysis. CT at diagnosis revealed iliosacral lymphadenomegaly, sternal lymphadenomegaly, bone metastasis and lung metastasis in 47.7%, 18.5%, 24.6% and 35.4% of the 65 included dogs, respectively. The overall median survival time was 196 days. On multivariable analysis, TCC localization (hazard ratio [HR], 1.90; P = .037), bone metastasis (HR, 2.76; P = .013) and sternal lymphadenomegaly (HR, 3.56; P = .004) were significantly associated with survival. Compared to the Bladder group (n = 16), the Urethra group (n = 26) had higher metastasis rates to the bone (6.3% vs 42.3%; P = .045) and lung (6.3% vs 46.2%; P = .022). The survival time was shorter in the Urethra group than in the Bladder group (121.5 vs 420 days; P < .001), and it was similar only in female dogs (247 vs 420 days; P = .031). These findings suggest that whole-body CT could be valuable for predicting the prognosis in urinary TCC.