Bladder & Prostate Cancer
Many cases of suspected prostate cancer in dogs may actually be transitional
cell carcinoma (TCC) of the urethra that is metastatic to the prostate.
TCC usually involves the neck of the bladder in the area called the trigone.
Both ureters from the kidneys dump their urine into the bladder in the
trigone area. It is easy to understand why a mass in this location may
cause a disturbance of urine flow. Pets often strain while trying to eliminate
urine.
They often urinate blood clots or blood stained urine (hematuria). This
activity appears or mimics a urinary tract infection, which can delay
the discovery of this cancer. Antibiotics often create an apparent improvement.
This masks the symptoms and further delays the diagnosis of this cancer.
The urethra and prostate are also common sites for TCC to strike. Widespread
seeding along the mucosal (inside) surface of the bladder makes surgery
ineffective to prolong survival. Late diagnosis is typical due to owner
delay and mimicry with cystitis.
Persistent hematuria(blood in urine) should urge pursuit of the diagnosis
with ultrasound, cystoscopy(a tubular instrument equipped to light the
infected area), fine needle aspirates(removal of liquids/gas) for cytology
(study of the cell) or true cut biopsy of the prostate.
The new tumor antigen test (V-BTA Test, Bion Diagnostic Sciences, Redmond
, Wash. ) may help diagnose TCC in its early stages as a screening test.
Unfortunately, hematuria causes false positives and since hematuria is
the chief symptom in TCC, the test is limited. Most Labs will run the
test but its application in hematuria cases may need to be interpreted
alongside ultrasound or double contrast radiography that visualize lesions.
Doctors seldom recommend surgery for bladder cancer, as it is unhelpful
and rarely enhances quality of life or longevity. TCC will eventually
spread to the local pelvic lymph nodes and cause death due to metastatic
disease, hydronephrosis, urinary obstruction, anemia and toxicity.
Dr.Villalobos often recommends treating TCC with Mitoxantrone (Blue Thunder),
Piroxicam and Pepcid. Data shows over a 50% response rate with reduction
of stranguria and hematuria in TCC for a valuable time period ranging
from 4-12 months.
Dr.Villalobos often starts her patient off with the Mitoxantrone at a
dose of 5mg/M2 to 5.5mg/M2 i.v. every 21-30 days. If the white blood cell
count was not depressed, then the dose would be increased to 6mg/M2 and
then 6.5mg/M2 incrementally or until symptoms regress.
Workers at Purdue University conducted a TCC study using the N-SAID, Piroxicam
(feldene), which is a prostaglandin antagonist of PGE-2, as a single agent
at 0.3mg/kg daily PO in 34 dogs. They reported 2 complete and 4 partial
responses at one and two months.
Stable disease was noted in 18 dogs and 10 cases progressed showing no
benefit. The median survival time for the 34 dogs was 181 days, which
compared favorably to the data reported using Cisplatin (We do not recommend
using this drug for TCC anymore).
In resistant cases, we will use Carboplatin at a dose of 300mg/M2 i.v.
every 21-30 days in dogs if there is no renal impairment. We use a lower
Carboplatin dose of 165mg/M2 to 200mg/M2 i.v. every 21-30 days in cats.
We like to administer subcutaneous fluids with Vitamin B and C complex
at each treatment to assist in diuresis and well being after treatment
for every patient.
We monitor the kidneys with blood work and ultrasound to detect hydronephrosis.
In selected cases we offer bladder drainage procedures that may be temporary
or permanent.
In the face of extreme blood loss due to severe hematuria, we will infuse
a 1% solution of formalin mixed with one vial of the topical ear solution,
Synotic, which has DMSO.
We will keep this solution in the bladder for 10-15 minutes then void
and flush out any clots. This procedure helped our patient, “Darcy”
Danko, survive an additional two precious weeks. Stopping severe hematuria
is life saving and much appreciated by the family.
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