Oncology 11 (tumors of the urinary system)

what is the most common urinary neoplasia in dogs?

invasive urothelial carcinoma (iUC)

aka invasive transitional cell carcinoma (TCC)

what are the risk factors of iUC in dogs?

-breed

-exposure to older gen. flea control/lawn chemicals

-obesity (not unique to iUC)

-cyclophosphamide exposure

-female gender

-neutered pets

what breeds are at high risk of developing iUC?

-scottish terriers

-eskumo dogs

-shelties

-westies

what diagnostics should be done every 6 months for dog breeds at risk of iUC?

urinary tract ultrasonography, UA, and sediment every 6 months

cytoscopy/biopsy suspicious lesions

where in the urinary tract is canine iUC often located?

in the trigone of the bladder

why can iUC located in the trigone of the bladder make local interventions difficult?

bc the trigone is the location of ureter connections and the urethral opening

what other areas of the urinary tract can canine iUC be located?

urethra and prostate (have to differentiate from prostatic carcinoma)

what are the common clinical signs of canine iUC?

common signs mimic UTIs:

-dysuria

-hematuria

-pollakiuria

-stranguria

-pyuria

-can have concurrent UTIs

-rarely lameness

when should you be concerned for iUC in patients with UTIs?

concern for iUC when resolution of clinical signs does not occur following antibiotic trial

in rare cases, how can iUC can lameness?

bone metastasis or hypertrophic osteopathy

what rectal exam findings are seen with canine iUC?

-thickened urethra or trigone region of bladder

-enlargement of LNs

-prostatomegaly in male dogs

-mass in bladder

-distended bladder

how is canine iUC diagnosed?

-CBC/serum chemistry

-urinalysis

-urine culture

how should urine be collected for UA in animals with suspected iUC?

via free-catch or catheterization

do not attempt to percutaneous FNA--> tumor seeding risk

what does definitive diagnosis of canine iUC often require?

histopathologic examination

how is canine iUC diagnosed with histopathologic examination?

via cystotomy, cytoscopy, or traumatic catheterization

IHC with uroplakin III and GATA-3

how does canine iUC metastasis occur?

via hematogenous or lymphatic routes

what is the metastatic rate of canine iUC?

on presentation: 14-16%

at euth/necropsy: 42-58%

what are the most common sites for canine iUC to metastasize?

regional LNs and lungs

other: liver, bone, skin

what imaging is used to stage canine iUC?

1. imaging of thoracic cavity (3-view rads, CT)

2. imaging of abdominal cavity (abdominal U/S, CT)

3. spinal rads, limbs rads (if lame)

what stage are the majority of dogs with iUC?

78% have T2, 20% have T3

what other diagnostic tests are used for diagnosis of canine iUC?

1. bladder tumor antigen (BTA) test

2. BRAF/cadet BRAF test

how accurate is the bladder tumor antigen (BTA) test for detecting canine iUC?

SN=90%, SP=40-80%

not very specific, should only be used as a screening test

what is the BRAF test for detecting canine iUC?

can detect as few as 10 mutation cells up to 4 months before clinical signs

mutation is present in urine samples from over 80% of all iUC cases

when is surgery indicated for treatment of canine iUC?

indicated only to:

-obtain tissue for definitive diagnosis

-eradicate lesions amendable to wide excision (distant from trigone)

-relieve urinary tract obstruction

how successful is surgery in treating canine iUC?

surgery is rarely curative, and not possible in most cases due to location

'field effect' causes malignant transformation of entire urothelium

what are the risks of using surgery to treat canine iUC?

procedural risk, recurrence, seeding

if electing to do surgery, what surgical procedures are performed to treat canine iUC?

1. full-thickness removal of discrete iUC lesions away from trigone

2. total cystectomy + urinary divergent strategies (serious complications limit success)

what is the MST of canine iUC treated with surgery + NSAIDs +/- chemo?

ranges from 348-722 days

what type of palliative surgery can be used for management of canine iUC?

prepubic cystostomy catheter

what are complications of a prepubic cystostomy catheter?

urine leakage

tumor seeding

infection

displacement

damage

when are stents indicated for local therapy of canine iUC?

urethral and ureteral stents can be placed in cases of obstruction

minimally invasive in most, but palliative

what are the risks of placing stents?

incontinence

stent fracture

migration

tumor progression

what are complications of using laser ablation for local therapy of canine iUC?

-perforation

-transient postprocedural worsening of stranguria/hematuria

-urethral stenosis and infection

how effective is radiation therapy in treating canine iUC?

iUC is considered moderatley radioresistant

use higher doses and less fractionation

what are side effects of using intensity-modulated and image guided radiation (IMRT/IGRT) for treating canine iUC?

acute side effects mild and self limiting (mild colitis)

late side effects in <10%

what is the MST of using intensity-modulated and image guided radiation (IMRT/IGRT) for treating canine iUC?

MST= 317 days

what is the protocol for low-dose palliative radiation for treating canine iUC?

10 daily fractions

what are the side effects of low dose palliative radiation for treating canine iUC?

acute side effects are mild, and no late side effects seen

what is the mainstay treatment of canine iUC?

chemotherapy

-COX inhibitors, chemotherapy, or combination

is chemotherapy for canine iUC curative?

usually not curative, but can lead to remission or stable disease (prevents tumor progression)

why is it important to remeasure iUC masses throughout chemotherapy treatment?

clinical signs do not consistently follow changes in tumor size- remeasuring iUC masses is essential

should be done in 8-12 week intervals

what percentage of dogs can iUC growth be controlled in with chemotherapy?

75-80% of dogs

QOL is usually very good

what is the complete response rate of canine iUC when using piroxicam alone? what is the progression free interval?

CR= 3%

PFI= 120 days

what is the complete response rate of canine iUC when using piroxicam and cisplatin?

14% complete response rate

what is the concern of using cisplatin as a chemotherapeutic?

high risk of toxicities (renal, GI, bone marrow)

what supportive/palliative care can be provided to dogs with iUC?

-NSAIDs/pain management

-catheterization (to relieve obstruction)

-avmaquin (sulforaphane producing product)

why is risk of concurrent UTIs high in dogs with iUC?

-urine retention

-abnormal epithelium/barrier

-compromised immune function

UTIs can worsen clinical signs and give false impression of cancer progression

what are prognostic factors of canine iUC?

1. location and tumor extent (prostatic involvement=increased risk of metastasis)

2. stage of disease (higher T stage= increased risk of nodal and distant mets)

3. age (younger age= increased risk of nodal mets)

4. treatment plan elected

how common are feline urinary bladder tumors?

rare

second most common site for urinary tract neoplasia in cats (after renal lymphoma)

what is the typical signalment of cats with urinary bladder tumors?

median age is 15 years (5-20 years)

no breed or sex predilection

what are the clinical signs of urinary bladder tumors in cats?

similar to dogs (hematuria, pollakiuria, stranguria), may have recurring UTIs

what are the common locations of feline urinary bladder tumors?

trigone (27%)

ventral wall (23%)

bladder apex (17%)

dorsal wall

multifocal/diffuse

lateral wall

what is the most common tumor type seen in feline urinary bladder cancers?

urothelial carcinoma or transitional cell most common

-mesenchymal, lymphoma, and others are less common

what are the common metastatic sites of feline urinary bladder tumors?

lungs, lymph nodes, abdominal carcinomatosis, kidney, ureter

~21% metastatic rate

what is the treatment for feline urinary bladder tumors?

similar to dogs (surgery, radiation, chemo, NSAIDs)

what is the overall survival time in cats with urinary bladder cancer left untreated?

46 days

what is the overall survival time in cats with urinary bladder cancer receiving medical management?

176 days

what is the overall survival time in cats with urinary bladder cancer receiving partial cystectomy +/- adjuvant therapy?

294 days