Treatment Of Transitional Cell Carcinoma Research Articles

Radiation toxicity grading after chemoradiotherapy of canine urinary tract carcinomas: Comparing VRTOG to VRTOG_v2.0.

Radiation toxicities may be underestimated after treatment of transitional cell carcinoma in dogs' lower urinary tract. Assessing acute and late toxicities and differentiating them from progressive disease (PD) impacts further therapeutic approach. We retrospectively assessed dogs treated with definitive-intent chemoradiotherapy (12 × 3.8 Gy, various first-line chemotherapeutics). Local tumour control, radiation toxicities and survival were evaluated. We classified radiation toxicities according to the previously published radiation toxicity scheme "VRTOG" as well as the updated version, "VRTOG_v2.0". Fourteen dogs with transitional cell carcinoma of bladder ± urethra (n = 8), +prostate (n = 3) or solely urethra (n = 3), were included. Median follow-up was 298 days (range 185-1798 days), median overall survival 305 days (95%CI = 209;402) and 28.6% deaths were tumour-progression-related. Acute radiation toxicity was mild and self-limiting with both classification systems: In VRTOG, 5 dogs showed grade 1, and 1 dog grade 2 toxicity. In VRTOG_v2.0, 2 dogs showed grade 1, 3 dogs grade 2, and 3 dogs grade 3 toxicity. Late toxicity was noted in 14.2% of dogs (2/14) with the VRTOG, both with grade 3 toxicity. With VRTOG_v2.0, a larger proportion of 42.9% of dogs (6/14) showed late toxicities: Four dogs grade 3 (persistent incontinence), 2 dogs grade 5 (urethral obstructions without PD resulting in euthanasia). At time of death, 5 dogs underwent further workup and only 3 were confirmed to have PD. With the updated VRTOG_v2.0 classification system, more dogs with probable late toxicity are registered, but it is ultimately difficult to distinguish these from disease progression as restaging remains to be the most robust determinant.

Subtotal urethrectomy and urethral-vaginal anastomosis for the treatment of transitional cell carcinoma of the urethra in a dog

A 10-year-old 4.7-kg spayed female mix breed dog presented with mucoid vaginal discharge despite treatment for cystitis for a month. A malignant neoplasm was suspected based on atypical cells found on vaginal mucus cytology. A cystoscopy biopsy was performed, and the histopathologic diagnosis was consistent with transitional cell carcinoma (TCC). A subtotal urethrectomy and urethral-vaginal anastomosis were performed. Treatment with piroxicam (0.3mg/kg eod for 1278 days) and carboplatin (150～250mg/m2/3～4 weeks, nine times) was initiated 2 weeks postoperatively. Other than recurrent cystitis that started 3 weeks postoperatively, the patient maintained a good quality of life with neither recurrence nor metastasis. The patient died of renal failure 3 years and 9 months (1395 days) after the initial visit. While TCC is generally considered to have poor prognosis, it was suggested from the management of this case that early diagnosis and radical surgery could achieve good long-term survival.

Irreversible Electroporation Balloon Therapy for Palliative Treatment of Obstructive Urethral Transitional Cell Carcinoma in Dogs.

Progression of transitional cell carcinoma (TCC) in dogs often leads to urinary obstruction. This observational pilot study aimed to evaluate the safety and efficacy of irreversible electroporation (IRE) balloon therapy for the palliative treatment of TCC with partial urethral obstruction. Three client-owned dogs diagnosed with TCC causing partial urethral obstruction were enrolled. After ultrasonographic and cystoscopic examination, IRE pulse protocols were delivered through a balloon catheter device inflated within the urethral lumen. After the procedure, the patients were kept overnight for monitoring and a recheck was planned 28 days later. No complication was observed during the procedure and postprocedural monitoring. After 28 days, one dog had a complete normalization of the urine stream, one dog had stable stranguria, and one dog was presented with a urethral obstruction secondary to progression of the TCC. On recheck ultrasound, one dog had a 38% diminution of the urethral mass diameter whereas the other two dogs had a mass stable in size. IRE balloon therapy seems to be a feasible and apparently safe minimally invasive novel therapy for the palliative treatment of TCC causing urethral obstruction. Further studies are needed to better characterize the safety, efficacy, and outcome of this therapy.

Tuberculous spondylitis following intravesical bcg-instillation in the treatment of transitional cell carcinoma: Case report and systematic review

ObjectivesTuberculous spondylitis (TS), also known as Pott’s disease (PD), is a form of tuberculosis in which the vertebral column is affected. Since the first description by Katz et al. in 1992, it became clear that Bacillus Calmette-Guérin (BCG) instillations in the treatment of superficial transitional cell carcinoma (TCC) form a plausible way in which PD is introduced. Nowadays, BCG forms the most effective treatment modality for superficial TCC. The incidence of other than minor complications have been estimated under five per cent. Here we report a case of TS after BCG-instillation in the treatment of TCC. Furthermore, all available literature concerning this topic was gathered into a systematic review. The primary objective was to create an overview of all available literature concerning TS after intravesical BCG-instillations, with an emphasis on the neurosurgical approach of these patients, forming a scaffold at which future case reports can be compared. As a secondary objective, we tried to raise the awareness concerning this very rare complication of intravesical BCG-instillation as a possible cause of low back pain (LBP). Patients and MethodsWe performed a systematic review, in which patients who developed TS after intravesical BCG-therapy in the treatment of TCC, were examined. A total of twenty-three articles (twenty-four cases) obtained from MEDLINE were included. Search terms included: “tuberculous spondylitis”, “Pott’s disease”, “vertebral osteomyelitis”, “intravesical”, “Bacillus Calmette-Guérin” and “transitional cell carcinoma”. Additional studies were identified by checking reference lists. Furthermore, we present a case concerning one of our own patients who consulted our Neurosurgical department with a similar clinical presentation. This systematic review is in conformity with the PRISMA-guidelines. The case report is in accordance with the CARE statement guidelines. ResultsResults are based on twenty-five cases (twenty-four cases extracted from previous literature and our case report). All included articles are case reports written in English. Publication year and recruitment time varies from 1992 to 2018. Mean age at clinical presentation varies from 35 to 94 years old (mean 74). All patients were male. Surgery was performed in 17 out of 25 cases (68%). A posterior approach was performed in seven cases (41%), zero anterior approaches (0%), a combined approach in five cases (29%) and not specified in five cases (29%). All patients received intravesical BCG-instillation in the treatment of TCC, ranging from one month to twelve years before clinical presentation (mean 26). Radiographic abnormalities were seen in thoracic vertebral segments in thirteen cases (52%), eleven cases in lumbar segments (44%), one at the thoracolumbar transition level (4%) and not in cervical vertebral segments. ConclusionAlthough very rare, TS should be part of the differential diagnosis in patients with LBP, even years after BCG-instillation for TCC. It mostly affects elderly men and involves the thoracolumbar spine through hematogenous spread via Batson’s plexus. Antitubercular therapy remains the mainstay in the treatment of TS. A posterior surgical approach, with debridement and stabilization, should be preferred when surgical intervention seems necessary. To our knowledge, this systematic review forms one of the first comprehensive reviews evaluating neurosurgical intervention for PD following intravesical BCG-therapy in the treatment of TCC.

Bilateral Double-Pigtail Ureteral Stent Placement for Management of Ureteral Obstruction Secondary to Transitional Cell Carcinoma in a Dog

Background: Transitional cell carcinoma (TCC) usually affects the trigone region of the bladder and proximal portion of the urethra. TCC in dogs is often complicated by local tumor invasion and obstruction of the urethra, ureters, or both. Urinary obstruction is the cause of death in approximately 60% of dogs with TCC. Radical surgeries are associated with morbidity and mortality rates. Stents have recently been evaluated for use in dogs with ureteral obstruction resulting from a variety of urinary tract tumors. This report aims to describe bilateral ureteral stent placement for treatment of malignant ureteral obstruction and long-term follow-up in a dog.Case: An 11‐year‐old female spayed Maltese with ureteral obstruction secondary to transitional cell carcinoma (TCC) in the bladder trigone. After palliative debulking procedure and diagnostic of TCC in bladder and NSAIDs treatment, recurrence has occurred causing ureteral obstruction and TCC had invaded the abdominal wall. Abdominal wall local tumor resection, trigone mass debulking and bilateral ureteral stent placement was made. A double-pigtail ureteral stent of appropriate length was advanced to bypass the ureteral obstruction. Stent sizes were 3.5 Fr in diameter and from 8 to 32 cm in length. The patient underwent surgical resection of the transitional cell carcinoma in the abdominal wall. The correct location of the bilateral ureteral pigtail stent was certified by abdominal radiography. Recovery was uneventful and the dog was discharged 2 days after surgery. Eleven months after stent placement, the dog developed lumbar vertebrae metastasis, without evidence of recurrent ureteral obstruction. The owners elected euthanasia 517 days after original presentation and 337 days after ureteral stent placement. Euthanasia was unrelated to the local tumor obstruction but was related to the bone metastasis.Discussion: Ureteral stent placement is feasible techniques for treatment of bladder TCC in dogs, with the objective of delaying the evolution of the disease and preventing ureteral obstruction. According to previous studies, although distant metastatic disease is worrisome, in the majority of dogs with bladder TCC, the primary location of the tumor is the most common cause of death. In patients with ureteral obstruction, early intervention preserves functional renal tissue. Thus, relief of obstruction should be recommended as soon as possible before irreversible renal damage occurs. The authors encourage aggressive and timely intervention, particularly when ureteral obstruction is bilateral. In the present report, 90 days postoperatively local recurrence causing ureteral obstruction was not evidenced on bladder ultrasound images and laboratory test follow-up. After this period, until 180 days after debulking surgery, tumor recurrence occurred, causing clinical signs and compromising renal function. Complications associated with stent placement included stent migration, recurrent ureteral obstruction, stranguria/pollakiuria, presumably due to irritation of the trigonal region from the distal stent; imperfect stent location; ureteral trauma during stent placement; and urinary tract infection. In the present report, the ureteral stents were placed for palliative treatment for malignant ureteral obstructions. Although urinary tract infection was recurrent, other complications associated with bilateral ureteral stent did not occur, such as accidental dislocation or stent obstruction by the tumor. The results obtained were satisfactory for urinary tract obstruction, allowing survival of 517 days. These findings may support long-term ureteral stenting in veterinary patients.

Lipoxygenase-5 Expression in Canine Urinary Bladder: Normal Urothelium, Cystitis and Transitional Cell Carcinoma

Transitional cell carcinoma (TCC) is the most common canine urinary tract tumour and mimics human invasive TCC. Human TCCs overexpress lipoxygenase (LOX)-5 and the use of target inhibitors has proven effective in inhibiting neoplastic growth. In this study, we investigated the immunohistochemical expression of LOX-5 in normal canine urinary bladder, cystitis and TCC. The comparative expression of LOX-5, cyclo-oxygenase (COX)-1 and COX-2 among the three tissue groups was also examined. Biopsy samples from cases of cystitis and TCC were reviewed from 2012 to 2016; samples of histologically normal bladder were used as controls. Dogs were excluded if they had received glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs) and/or chemotherapy prior to tissue collection. LOX-5 was expressed in 95% of TCCs, 23% of cases of cystitis and 10% of controls. LOX-5 and COX-2 immunohistochemistry scores were significantly (P<0.01) higher in TCCs versus cystitis and normal bladders. Results of this study support the rationale for further investigation of the use of NSAIDs with dual anti COX-2 and LOX-5 effect for the treatment of canine TCC.

Identifying the ErbB/MAPK Signaling Cascade as a Therapeutic Target in Canine Bladder Cancer.

Transitional cell carcinoma (TCC) of the bladder comprises 2% of diagnosed canine cancers. TCC tumors are generally inoperable and unresponsive to traditional chemotherapy, indicating a need for more effective therapies. BRAF, a kinase in the mitogen-activated protein kinase (MAPK) pathway, is mutated in 70% of canine TCCs. In this study, we use BRAF mutant and wild-type TCC cell lines to characterize the role of BRAF mutations in TCC pathogenesis and assess the efficacy of inhibition of the MAPK pathway alone and in combination with other gene targets as a treatment for canine TCC. Analysis of MAPK target gene expression and assessment of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation following serum starvation indicated constitutive MAPK activity in all TCC cell lines. BRAF mutant TCC cell lines were insensitive to the BRAF inhibitor vemurafenib, with IC50 values greater than 5 μM, but exhibited greater sensitivity to a paradox-breaking BRAF inhibitor (IC50: 0.2-1 μM). All TCC cell lines had IC50 values less than 7 nM to the mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor trametinib independent of their BRAF mutation status. ERK1/2 phosphorylation decreased after 6-hour treatments with MAPK inhibitors, but rebounded by 24 hours, suggesting the presence of resistance mechanisms. Microarray analysis identified elevated expression of the ErbB family of receptors and ligands in TCC cell lines. The pan-ErbB inhibitor sapitinib synergized with BRAF inhibition in BRAF mutant Bliley TCC cells and synergized with MEK1/2 inhibition in Bliley and BRAF wild-type Kinsey cells. These findings suggest the potential for combined MAPK and ErbB receptor inhibition as a therapy for canine TCC. SIGNIFICANCE STATEMENT: The results of this study (1) identify a novel combination strategy for canine bladder cancer treatment: targeting the ErbB/MAPK signaling cascade and (2) establish the utility of canine bladder cancer as a naturally-occurring model for human MAPK-driven cancers.

Targeting the ErbB/MAPK Signaling Cascade in Canine Bladder Cancer Cell Lines

Canine transitional cell carcinoma (TCC) of the bladder accounts for 2% of diagnosed canine cancers. Most TCCs are inoperable and unresponsive to traditional chemotherapy. Median survival time is typically less than a year for all treatments indicating a need for more effective therapies. Recent studies have discovered that approximately 70% of canine TCCs harbor mutations in the proto‐oncogene BRAF, a kinase involved in the mitogen‐activated protein kinase (MAPK) pathway that controls cell proliferation, differentiation, and apoptosis. BRAF mutations are present in several human cancers, most of which exhibit adaptive or intrinsic resistance to BRAF‐targeted inhibitors. The goals of this study were to (1) further characterize the role of mutant BRAF in canine TCC and (2) determine whether inhibition of the MAPK pathway alone or in combination with other gene targets may be an effective therapy for TCC treatment.Analysis of ERK1/2 phosphorylation following serum starvation indicates that TCC cell lines exhibit constitutive MAPK pathway activation independent of their BRAF mutation status. MAPK activity was further quantified using gene expression analysis of ten MAPK target genes, revealing that TCC cell lines have significantly higher MAPK pathway activity compared to other canine cancer cell lines. These data suggest a causative role for MAPK signaling in TCC pathogenesis. To determine whether the MAPK pathway could be a therapeutic target for TCC treatment we assessed the effect of BRAF and MEK inhibition on TCC cell proliferation and ERK1/2 phosphorylation. Four BRAF mutant human cell lines with varying degrees of sensitivity to BRAF‐targeted agents were used to determine the relative sensitivity of canine TCC cell lines. BRAF mutant TCC cell lines were sensitive to BRAF inhibition with the “paradox‐breaking” inhibitor PLX7904 (IC50: 0.2–1.2μM), but not vemurafenib (IC50: 7–21μM). Both BRAF wild type and mutant TCC cell lines were sensitive to MEK inhibition with selumetinib (IC50: 15–420nM) and trametinib (IC50: 0.4–8nM). ERK1/2 phosphorylation decreased after 6‐hour treatments with MAPK inhibitors, but rebounded by 24 hours suggesting the presence of resistance mechanisms. Microarray analysis indicated that the ErbB family of receptors and ligands are up‐regulated in TCC cell lines relative to other canine cancer cell lines (fold‐change &gt; 2, q &lt; 0.05). Combined BRAF and ErbB inhibition synergized in the BRAF mutant Bliley TCC cell line, while combined MEK and ErbB inhibition synergized in both Bliley and BRAF wild type Kinsey cells. These findings suggest that targeting ErbB receptors with MAPK inhibition is a potential therapy for canine TCC treatment. Additionally, our data indicate that canine TCC may serve as a naturally‐occurring model for the study of resistance mechanisms to MAPK inhibition in human cancers.Support or Funding InformationMorris Animal Foundation, Shipley University Chair in Comparative OncologyThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Lower Urinary Tract Neoplasia.

Lower urinary tract neoplasia in companion animals is a debilitating and often life-threatening disease. Tumors of the bladder, urethra, and prostate often occur independently, although extension of these tumors into adjacent regions of the lower urinary tract is documented frequently. The most common lower urinary tract tumor in dogs and cats is transitional cell carcinoma (TCC). In both dogs and cats, TCC affecting the urinary bladder is generally considered to be highly aggressive with both local and metastatic disease potential, and this disease poses unique treatment challenges. Whereas much literature exists regarding the TCC disease process, treatment options, and prognosis in dogs, relatively few studies on feline TCC have been published due to the lower incidence of TCC in this species. Prostate tumors, most commonly adenocarcinomas, occur less commonly in dogs and cats but serve an important role as a comparative model for prostate neoplasia in humans. This article serves as a review of the current information regarding canine and feline lower urinary tract neoplasia as well as the relevance of these diseases with respect to their human counterparts.

BOXIT—A Randomised Phase III Placebo-controlled Trial Evaluating the Addition of Celecoxib to Standard Treatment of Transitional Cell Carcinoma of the Bladder (CRUK/07/004)

BackgroundNon–muscle-invasive bladder cancer (NMIBC) has a significant risk of recurrence despite adjuvant intravesical therapy. ObjectiveTo determine whether celecoxib, a cyclo-oxygenase 2 inhibitor, reduces the risk of recurrence in NMIBC patients receiving standard treatment. Design, setting, and participantsBOXIT (CRUK/07/004, ISRCTN84681538) is a double-blinded, phase III, randomised controlled trial. Patients aged ≥18 yr with intermediate- or high-risk NMIBC were accrued across 51 UK centres between 1 November 2007 and 23 July 2012. InterventionPatients were randomised (1:1) to celecoxib 200mg twice daily or placebo for 2 yr. Patients with intermediate-risk NMIBC were recommended to receive six weekly mitomycin C instillations; high-risk NMIBC cases received six weekly bacillus Calmette-Guérin and maintenance therapy. Outcome measurements and statistical analysisThe primary endpoint was time to disease recurrence. Analysis was by intention to treat. Results and limitationsA total of 472 patients were randomised (236:236). With median follow-up of 44 mo (interquartile range: 36–57), 3-yr recurrence-free rate (95% confidence interval) was as follows: celecoxib 68% (61–74%) versus placebo 64% (57–70%; hazard ratio [HR] 0.82 [0.60–1.12], p=0.2). There was no difference in high-risk (HR 0.77 [0.52–1.15], p=0.2) or intermediate-risk (HR 0.90 [0.55–1.48], p=0.7) NMIBC. Subgroup analysis suggested that time to recurrence was longer in pT1 NMIBC patients treated with celecoxib compared with those receiving placebo (HR 0.53 [0.30–0.94], interaction test p=0.04). The 3-yr progression rates in high-risk patients were low: 10% (6.5–17%) and 9.7% (6.0–15%) in celecoxib and placebo arms, respectively. Incidence of serious cardiovascular events was higher in celecoxib (5.2%) than in placebo (1.7%) group (difference +3.4% [–0.3% to 7.2%], p=0.07). ConclusionsBOXIT did not show that celecoxib reduces the risk of recurrence in intermediate- or high-risk NMIBC, although celecoxib was associated with delayed time to recurrence in pT1 NMIBC patients. The increased risk of cardiovascular events does not support the use of celecoxib. Patient summaryCelecoxib was not shown to reduce the risk of recurrence in intermediate- or high-risk non–muscle-invasive bladder cancer (NMIBC), although celecoxib was associated with delayed time to recurrence in pT1 NMIBC patients. The increased risk of cardiovascular events does not support the use of celecoxib.

Silibinin attenuates TGF‑β1‑induced migration and invasion via EMT suppression and is associated with COX‑2 downregulation in bladder transitional cell carcinoma.

Transforming growth factor (TGF)‑β1 is highly expressed in bladder transitional cell carcinoma (TCC) and is positively associated with tumor grade. TGF‑β1 signaling promotes cell metastasis by inducing epithelial‑mesenchymal transition (EMT), however, the underlying mechanisms are not fully understood. Our previous study demonstrated the anti‑metastatic effects of silibinin, a natural flavonoid derived from milk thistle, against TCC. The present study investigated the effects of silibinin on TGF‑β1‑induced EMT in TCC, focusing on the role of prostaglandin‑endoperoxide synthase2 (COX‑2). Cell migration was determined by a wound healing assay and Transwell migration assay, and cell invasion was investigated using a Transwell invasion assay. Cell morphology was observed using an inverted microscope. Cell viability was evaluated by an MTT and cell counting assays. EMT markers were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting. Specific small interfering RNA was used to knockdown COX‑2 gene expression. TGF‑β1 promoted cell migration and invasion, induced EMT and upregulated the expression of COX‑2. COX‑2 knockdown attenuated TGF‑β1‑induced EMT, indicating that COX‑2 upregulation was essential for TGF‑β1‑induced EMT. Silibinin attenuated TGF‑β1‑induced migration and invasion by inhibiting EMT, and was associated with COX‑2 downregulation. TGF‑β1‑induced COX‑2 upregulation, which was inhibited by silibinin. In addition, TGF‑β1‑induced EMT was further inhibited when silibinin treatment was combined with COX‑2‑knockdown. The results suggested that silibinin may be a potential future treatment for metastatic TCC.

Transitional cell carcinoma with extension of the renal vein and IVC tumor thrombus: report of three cases and literature review

BackgroundTransitional cell carcinoma (TCC) originating from the renal pelvis with a venous tumor thrombus is a rare entity. However, clinicians should be aware of it because of its high malignancy and poor prognosis.Case presentationHere, we report three cases of pathologically confirmed TCC originating from the renal pelvis with extension into the renal vein or inferior vena cava (IVC). Of these patients, two are males and one is female (58~73 years old). Their main symptom is flank pain; besides, gross hematuria and weight loss is observed in one of the patients. Computed tomography (CT) scan of the first patient revealed multiple space-occupying lesions in the left renal pelvis and left medium and lower ureter with a tumor thrombus in the left renal vein. CT scan of the second patient revealed a right renal mass and extension into the IVC. Abdominal magnetic resonance imaging (MRI) of the third patient showed a soft tissue mass in the region of the left renal sinus, and the signal of the soft tissue was observed in the left renal vein. The preoperative diagnoses of the first and third patient were TCC, while the second patient was renal cell carcinoma (RCC). Two patients with the preoperative diagnosis of TCC underwent laparoscopic radical nephroureterectomy with thrombectomy, and the other patient underwent radical nephrectomy with thrombectomy. The surgeries were successful. Although two of our patients underwent chemotherapy and radiotherapy, they died 2 and 19 months after the surgery, respectively. The other patient refused any adjuvant therapy and died 3 months after the operation.ConclusionsCompared to the extension of RCC to the renal vein or IVC, extension of TCC to the renal vein or IVC is rare. TCC with a venous tumor thrombus is often misdiagnosed as RCC. However, a correct preoperative or intraoperative diagnosis is of great importance to decide surgical strategy. Laparoscopic radical nephroureterectomy with thrombectomy may be a safe and feasible operative method in treatment of TCC with a renal vein thrombus. The prognosis of such cases is poor even if chemotherapy and radiotherapy are scheduled.

A pilot study of toceranib/vinblastine therapy for canine transitional cell carcinoma.

BackgroundEffective therapies for transitional cell carcinoma (TCC) are limited, with objective response rates to most chemotherapeutic regimens below 20%. The purpose of this study was to investigate the biologic activity of combined toceranib phosphate and vinblastine chemotherapy for treatment of TCC. A secondary objective was to compare the utility of Computed Tomography (CT) and abdominal ultrasound (AUS) in tumor response assessments.ResultsDogs with TCC received vinblastine at 1.6 mg/m2 every 2 weeks and toceranib at 2.5–2.75 mg/kg on Monday/Wednesday/Friday. Tumor monitoring was achieved through CT and AUS. Five patients completed the 16-week study. Based on AUS assessments, 3 dogs experienced biologic response to therapy including partial responses (PR, n = 2) and stable disease (SD, n = 1). Based on CT, 5 dogs experienced a biologic response (n = 2 PR, n = 3 SD). Both imaging modalities (ultrasound and CT) were found to provide repeatable measurements between operators, however agreement between operator measurements was greater when CT images were used to assess tumor size.ConclusionsThe combination of toceranib and vinblastine did not result in improved response rates. While agreement in tumor volume assessments between both AUS and CT were excellent between operators, this did not extend to assessment of tumor response. The higher rate of concordance between operators when assessing response to treatment with CT suggests that CT should be considered for future clinical trials involving canine bladder TCC to improve the accuracy and repeatability of tumor measurement. The data suggest that response to therapy as assessed by AUS or CT do not predict duration of clinical response.

Canine transitional cell carcinoma: a review of current paradigms

Transitional cell carcinoma (TCC) is the most common tumour of the canine urinary bladder. It is highly locally invasive and carries a moderate to high risk of metastasis. Clinical signs are typically attributed to the primary disease, and may mimic those of a lower urinary tract infection. The gold standard for definitive diagnosis is histopathology of tissue obtained by traumatic catheterisation, cystoscopy or surgery. Staging includes thoracic and abdominal imaging to aid in the determination of prognosis. Due to the limitations of local treatment for TCC, medical treatment with systemic chemotherapy and non-steroidal anti-inflammatories remains the mainstay of therapy. Surgery is rarely feasible as the most common location for TCC is the trigone. With the rapid development of interventional radiology in veterinary medicine during the last decade, urethral stents have become a non-invasive and effective approach for relieving partial or complete malignant urinary obstructions, which are common in dogs with advanced TCC.

Hedgehog signaling is activated in canine transitional cell carcinoma and contributes to cell proliferation and survival.

Transitional cell carcinoma (TCC) is the most commonly diagnosed tumor of the canine urinary system. Hedgehog (HH) signaling represents one possible novel therapeutic target, based on its recently identified central role in human urothelial carcinoma. The purpose of this study was to determine if HH mediators are expressed in canine TCC and the effect of inhibition of this pathway on cell growth and survival. HH pathway mediators were found to be expressed in five canine TCC cell lines. Indian HH was expressed in tumor cells in five canine bladder tumor tissues, but not in normal canine bladder tissue. Inhibition of HH signaling with cyclopamine and GANT61 led to significantly decreased cell proliferation but had a smaller effect on apoptosis. These results support future investigation of inhibitors of HH signaling in the treatment of canine TCC.

A single-arm, multicenter, open-label phase II trial of cabazitaxel as second-line treatment for patients with locally advanced or metastatic transitional cell carcinoma (TCC).

372 Background: For patients with advanced TCC who have progressed on a platinum-based regimen, no widely accepted standard second line therapy currently exists. A 2-stage phase II study was conducted to assess the activity and toxicity profile of the microtubule inhibitor cabazitaxel (Jevtana; FDA-approved in hormone-refractory metastatic prostate cancer previously treated with a docetaxel-containing regimen) in patients with metastatic TCC after failure of prior platinum-based chemotherapy. ClinicalTrials.gov NCT01600339. Methods: Patients with one prior platinum based systemic therapy for metastatic TCC received cabazitaxel at a dose of 25 mg\m2every 21 days with prophylactic GCSF support, until disease progression or unacceptable toxicity. The primary endpoint was objective tumor response rate (ORR). Secondary endpoints included safety, time to progression (TTP), and overall survival (OS). Results: Twenty-three patients were enrolled to the study, 19 of whom received treatment. Male\female ratio was 15\4 and the median age was 67 (range, 56-81) years. Partial response (PR) was observed in 1 patient (5.3%), 10 patients (52.6%) achieved stable disease (SD), including 8 (42.1%) that had prolonged SD (≥16 weeks).Furthermore, the disease control rate (PR or prolonged SD) was 47.4%. The median TTP and OS were 4.2 (95% CI, 2.0-6.0) months and 9.9 (95% CI 5.6-13.2) months, respectively. The median number of treatment cycles was 5 (range 1-10). One patient experienced Grade 5 toxicity. Neutropenic fever occurred in 10.6% of patients. Most common toxicities were anemia and diarrhea. Conclusions: Cabazitaxel had modest efficacy in the treatment of advanced TCC, and there was no evidence of a significant response. Toxicity profile was considerable. The role of Cabazitaxel in urothelial carcinoma may need further evaluation in rational combination strategies, but not as a single agent. Clinical trial information: NCT01600339.

The differential expression of EphB2 and EphB4 receptor kinases in normal bladder and in transitional cell carcinoma of the bladder.

Effective treatment of transitional cell carcinoma (TCC) of the bladder requires early diagnosis. Identifying novel molecular markers in TCC would guide the development of diagnostic and therapeutic targets. Ephrins mediate signals via tyrosine kinase activity that modulates diverse physiologic and developmental processes, and ephrins are increasingly implicated in carcinogenesis. The aim of our study was to examine the differential regulation of EphB4 and EphB2 in normal bladder and in TCC of the bladder in 40 patients undergoing radical cystectomy for curative intent. Immunostaining and Western blotting revealed that normal urothelium expresses EphB2 (20 of 24 cases, 83% of the time) not EphB4 (0 of 24 cases, 0%). In sharp contrast, TCC specimens show loss of EphB2 expression (0 of 34 cases, 0%) and gain of EphB4 expression (32 of 34, 94%). Furthermore, EphB4 signal strength statistically correlated with higher tumor stage, and trended toward the presence of carcinoma in situ (CIS). These results are confirmed by analysis of normal urothelial and tumor cell lines. EphB2 is not a survival factor in normal urothelium, while EphB4 is a survival factor in TCC. Treatment of bladder tumor xenograft with an EphB4 inhibitor sEphB4-HSA leads to 62% tumor regression and complete remission when combined with Bevacizumab. Furthermore, tissue analysis revealed that sEphB4-HSA led to increased apoptosis, decreased proliferation, and reduced vessel density, implicating direct tumor cell targeting as well as anti-angiogenesis effect. In summary loss of EphB2 and gain of EphB4 expression represents an inflection point in the development, growth and possibly progression of TCC. Therapeutic compounds targeting EphB4 have potential for diagnosing and treating TCC.

Short-Term Resveratrol Exposure Causes In Vitro and In Vivo Growth Inhibition and Apoptosis of Bladder Cancer Cells

Conventional adjuvant chemotherapies for bladder transitional cell carcinomas (TCCs) may cause strong systemic toxicity and local irritation. Non-toxic resveratrol inhibits TCC cell growth but its feasibility in clinical management of TCCs remains obscure. This study aimed to evaluate the safety and anti-TCC efficacy of resveratrol, using the experimental models closer to the clinical treatment condition. Human TCC EJ cells were exposed to 100 µM, 150 µM and 200 µM resveratrol respectively for 1 hour and 2 hours to mimic intravesical drug instillation and the cell responses were analyzed by multiple experimental approaches. An orthotopic TCC nude mouse model was established by injecting EJ cells into the sub-urothelial layer and used for short-term intravesical resveratrol instillation. The safety of resveratrol instillation was evaluated and compared with that of MCC. The results revealed that 2 h 150 µM or 200 µM resveratrol treatment leaded to remarkable S phase arrest and apoptosis at 72 h time-point, accompanied with attenuated phosphorylation, nuclear translocation and transcription of STAT3, down-regulation of STAT3 downstream genes (survivin, cyclinD1, c-Myc and VEGF) and nuclear translocations of Sirt1 and p53. The importance of STAT3 signaling in cell growth was confirmed by treating EJ cells with JAK2 inhibitor tyrphostin AG490. The efficacy and safety of resveratrol instillation were proved by the findings from nude mouse orthotopic xenograft models, because this treatment caused growth suppression, distinctive apoptosis and STAT3 inactivation of the transplanted tumors without affecting normal urothelium. Our results thus suggest for the first time the practical values of resveratrol as a safe and effective agent in the post-operative treatment of TCCs.

Total Cystectomy for Treatment of Transitional Cell Carcinoma of the Urethra and Bladder Trigone in a Dog

To report total cystectomy with reimplantation of the ureters in the proximal aspect of the vagina. Case report. An 11-year-old female spayed Vizsla with spontaneously occurring transitional cell carcinoma of the urethra and bladder. After initial treatment for transitional cell carcinoma of the bladder trigone with urethral stent placement and chemotherapy, the dog developed urinary incontinence 2 months after stent placement. Eleven months after initial diagnosis, the dog developed pulmonary metastasis and local progression, leading to bilateral ureteral dilatation. After palliative radiation, total cystectomy was performed. The owners elected euthanasia 442 days after original presentation and 92 days after total cystectomy. Euthanasia was unrelated to the surgical procedure, but was related to the primary disease. Total cystectomy is a technically feasible procedure that should be considered for the treatment of bladder cancer in dogs.

Abstract B52: Targeting epigenetic dysregulation in a canine model of bladder cancer

Abstract Bladder cancer, which consists mainly of Transitional Cell Carcinoma (TCC), is the fifth most common cancer in the United States with over 70,000 cases and 15,000 deaths expected in 2013. Despite the successful development of molecularly targeted therapeutics for many cancers, there has been little change in the standard of care for TCC patients over the last few decades. New studies have revealed that aberrant epigenetic events, such as DNA hypermethylation and altered histone modifications, are common in TCC and are thought to promote tumorigenesis. Epigenetic therapies targeting these dysregulated pathways may reverse these effects and can have a profound influence on tumor growth. One such epigenetic modifier, EZH2, the catalytic subunit of polycomb repressive complex 2 (PRC2), is overexpressed in a variety of cancers and was found to enhance tumor progression by silencing several tumor suppressor genes. Recently, we have verified that EZH2 is upregulated in human TCC through an FGF2-NDY1/KDM2B-dependent suppression of miR-101. These data suggest that FGF2-NDY1/KDM2B-EZH2 pathway may be important in transitional cell carcinogenesis and may provide relevant epigenetic targets for the treatment of TCC. Spontaneous canine TCC also exhibits activation of FGF2 signaling and has been suggested as a model for bladder cancer. Therefore, we hypothesized that the development of aberrant epigenetic mechanisms downstream of FGF2 would be conserved between humans and dogs and that canine TCC could serve as a relevant large animal model for the clinical targeting of the FGF2-NDY1-EZH2 axis. To test our hypothesis, we employed canine TCC cell lines that we developed from dogs of various breeds and found that both EZH2 and NDY1/KDM2B are upregulated in canine TCC when compared to normal tissue. In order to target the pathway, we inhibited EZH2 both pharmacologically, using the commercially available inhibitor DZNep (3-deazaneplanocin), and through targeted knockdown. We determined that both DZNep and shRNA knockdown of EZH2 inhibited proliferation and induced apoptosis in canine TCC cells in anchorage-dependent (2D) and anchorage-independent (3D) cultures. By conducting these experiments in parallel with human TCC cell lines, we showed that sensitivity to DZNep is comparable between human and canine TCC cell lines. Western blot analysis and qRT-PCR demonstrated that, upon DZNep treatment, there is reduction of EZH2 at the protein level and inhibition of its activity, as evidenced by decreased global trimethylation of Histone H3 at lysine 27 (H3K27me3). Furthermore, inhibition of EZH2 was associated with upregulation of a set of genes that are commonly silenced by H3K27me3. Human and canine bladder cancer share histopathologic characteristics and clinical behavior. With this study, we confirm that the molecular underpinnings of spontaneous TCC are also shared between dogs and humans. Therefore canine TCC provides a means to understand epigenetic dysregulation in the urothelium as well as to investigate its clinical targeting. Citation Format: Parthena Foltopoulou, Monica Betancur-Boissel, Philip N. Tsichlis, Elizabeth A. McNiel. Targeting epigenetic dysregulation in a canine model of bladder cancer. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr B52.