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

A chromosome-scale fishing cat reference genome for the evaluation of potential germline risk variants

The fishing cat, Prionailurus viverrinus, faces a population decline, increasing the importance of maintaining healthy zoo populations. Unfortunately, zoo-managed individuals currently face a high prevalence of transitional cell carcinoma (TCC), a form of bladder cancer. To investigate the genetics of inherited diseases among captive fishing cats, we present a chromosome-scale assembly, generate the pedigree of the zoo-managed population, reaffirm the close genetic relationship with the Asian leopard cat (Prionailurus bengalensis), and identify 7.4 million single nucleotide variants (SNVs) and 23,432 structural variants (SVs) from whole genome sequencing (WGS) data of healthy and TCC cats. Only BRCA2 was found to have a high recurrent number of missense mutations in fishing cats diagnosed with TCC when compared to inherited human cancer risk variants. These new fishing cat genomic resources will aid conservation efforts to improve their genetic fitness and enhance the comparative study of feline genomes.

Evaluation of a multiagent chemotherapy protocol combining vincristine, cyclophosphamide, mitoxantrone and prednisolone (CMOP) for treatment of feline intermediate-large cell lymphoma

OBJECTIVES

The aim of this study was to determine response rates, median progression-free intervals (PFIs) and median survival times (MSTs) for cats with intermediate-large cell lymphoma treated with a vincristine, cyclophosphamide, mitoxantrone and prednisolone (CMOP) protocol. A secondary objective was to determine the tolerability of mitoxantrone used within this multiagent protocol.

METHODS

The medical records of 31 cats treated at a single institution between 2009 and 2022 were reviewed to identify suitable cases. Cats were included in the study if they had a confirmed diagnosis of intermediate-large cell lymphoma, had received a CMOP protocol as first-line treatment and had completed at least one 4-week cycle of this protocol. Modifications allowed in the protocol included the use of l-asparaginase, vinblastine substitution for vincristine, chlorambucil substitution for cyclophosphamide and dexamethasone or methylprednisolone substitution for prednisolone.

RESULTS

The overall response rate was 74% (n = 23), with 45% (n = 14) achieving complete remission (CR), 29% (n = 9) achieving partial remission (PR) and 26% (n = 8) achieving stable disease (SD). The Kaplan-Meier median PFI and MST were 139 days and 206 days, respectively. Responders (CR or PR) had a significantly longer (P <0.001) median PFI and MST compared with non-responders (SD) (176 days vs 62 days, and 251 days vs 61 days, respectively). Cats that achieved CR had a significantly longer median PFI and MST (P <0.001) at 178 days and 1176 days, respectively. The 6-month and 1- and 2-year survival rates in cats with CR were 64%, 57% and 35%, respectively. Treatment with mitoxantrone was generally well tolerated, with no cats experiencing Veterinary Cooperative Oncology Group adverse effects above grade 2.

CONCLUSIONS AND RELEVANCE

The CMOP protocol is an alternative and well-tolerated treatment for cats with intermediate-large cell lymphoma. As demonstrated with previous chemotherapy protocols, cats that respond to treatment, particularly those that achieve CR, are likely to have more durable responses.

Urinary bladder hemangiosarcoma in a cat treated with partial cystectomy and adjuvant metronomic cyclophosphamide and thalidomide

Visceral hemangiosarcomas (HSA) are rare in cats and typically associated with aggressive biologic behavior and poor prognosis. A 4-year-old male neutered domestic shorthair cat was presented with a 3-month history of hematuria and stranguria; ultrasonography identified a large bladder mass. Complete excision was achieved by partial cystectomy. Histopathology and immunohistochemistry for von Willebrand factor confirmed HSA. The cat was treated using adjuvant cyclophosphamide, thalidomide, and meloxicam for 8 months. Abdominal ultrasonography repeated at 2 months and computed tomography repeated at 5 and 19 months after diagnosis showed no evidence of local recurrence or metastasis. The cat was alive at last follow-up (896 days). Although the cat described in this report experienced a more favorable prognosis compared to other visceral HSA locations, additional cases are needed to further understand the biological behavior of bladder HSAs and guide treatment decisions.

Palliative radiation therapy as a treatment for feline urinary bladder masses in four cats

CASE SERIES SUMMARY

Urinary bladder masses in four cats were treated with palliative radiation therapy (RT). Three cats were previously diagnosed with chronic kidney disease (CKD): International Renal Interest Society (IRIS) stage 2 in two cats and IRIS stage 3 in one cat. One cat had a diagnosis of hyperthyroidism and inflammatory bowel disease. Three cats had urinary tract infections diagnosed by urine culture and susceptibility testing prior to or during treatment. All patients had urine cytospin cytology performed; one case showed suspect urothelial carcinoma and three had no cytological evidence of neoplasia. All clients declined further sampling from the bladder masses. Therefore, cytologic/histologic diagnosis in all cases was not available. An abdominal ultrasound was performed in all cats, which revealed urinary bladder mass(es) prior to referral for RT. Three cats had pretreatment thoracic radiographs, which revealed no evidence of pulmonary metastasis. An abdominal CT was performed in all cases and one case had thoracic CT performed for staging. The thoracic CT showed a focal lesion of unknown etiology in the right caudal lung lobe. Palliative RT was performed with four weekly 6 Gy fractions (24 Gy in total). The urinary signs in all cats resolved over the course of RT: after the first RT treatment in two cats and after the second RT treatment in two cats. There were two Veterinary Radiation Therapy Oncology Group grade 1 gastrointestinal and one grade 2 genitourinary acute RT side effects.

RELEVANCE AND NOVEL INFORMATION

This is the first report in the literature of a standardized RT protocol as a treatment option for feline urinary bladder masses.

Modified Toyoda technique for total cystectomy and cutaneous ureterostomy in a cat

OBJECTIVES

To report the technique and outcome of a cat treated with a total cystectomy and bilateral cutaneous ureterostomy.

ANIMALS

A 16-year-old male castrated domestic shorthair cat.

STUDY DESIGN

Case report.

CASE PRESENTATION

A cat was referred after a 2-week history of pollakiuria and hematuria. Transitional cell carcinoma (TCC) was suspected based on ultrasonographic, cytologic, and contrast computed tomographic (CT) findings. A total cystectomy was combined with a modified cutaneous ureterostomy: the ureter, incised like a fish-mouth aperture, was anastomosed to the skin after the creation of a rectangular-shaped defect. Complete excision of a TCC was confirmed histologically.

RESULTS

Ureteral stents were removed 7 days (left) and 28 days (right) postoperatively. The cat's incontinence was managed with an absorbent diaper surrounding the ureteral stomata. The right ureter became obstructed 14 months after surgery, and the cat died at home approximately 16 months after surgery. In spite of the urinary incontinence, the owner was satisfied with the surgery and evaluated the cat's quality of life as satisfactory.

CONCLUSIONS

The total cystectomy and cutaneous ureterostomy described here allowed urinary excretion and resulted in long-term survival of a cat with bladder TCC.

Metastatic urothelial carcinoma of the urinary bladder in a Sumatran tiger (Panthera tigris sondaica)

A 15-year-old spayed female Sumatran tiger (Panthera tigris sondaica) was presented with a short history of haematuria and dysuria, non-responsive to antibiotics, and a gradual decline to inappetence over a period of 2-3 months. Ultrasound examination showed a thickened urinary bladder wall and the renal pelvis of right kidney was dilated and cystic. A presumptive diagnosis of renal failure was made, and the tigress was euthanised due to deteriorating quality of life and pronounced weight loss. Histopathology revealed extensive erosion of the urinary bladder wall and marked congestion of the submucosal vasculature, a potential cause of the haematuria observed clinically. Numerous foci of neoplastic cells were also observed throughout the lung parenchyma as well as within lymphatic vessels of the lung, the liver and the kidney. A diagnosis of a metastatic non-papillary high-grade urothelial carcinoma (UC) of the urinary bladder was made. Consistent with this diagnosis, immunohistochemistry revealed the neoplastic cells were negative for uroplakin III, as has been reported for a subset of high-grade, infiltrative urinary bladder UCs of canines and humans. This is the first report of a primary tumour of the urinary bladder in a tiger and the first report of UC in a tiger.

Stenting of Malignant Urinary Tract Obstructions in Humans and Companion Animals

Urine retention secondary to neoplastic obstructions of the upper and lower urinary tracts is a life-threatening condition in both humans and companion animals. Stents can be placed to temporarily or permanently open obstructed urinary tract lumens and are often able to be placed using minimally invasive techniques with guidance via ultrasonography or fluoroscopy. The literature for these techniques is vast for humans and growing for companion animals. The below review provides a discussion of the principles of stenting and types of ureteral and urethral stents, as well as the techniques for placing these stents in humans and companion animals.

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.

Feline abdominal ultrasonography: What's normal? What's abnormal? Renal pelvis, ureters and urinary bladder

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the urinary tract provides important information useful in the investigation of several conditions including ureteral obstruction and cystitis.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as lipid droplets in the bladder, and pathological changes can be challenging.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased renal pelvis, ureters and urinary bladder. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Ultrasound examination of the kidneys and perinephric space was discussed in an article published in May 2020.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

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.