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.