Radiation Oncology: Bladder and Prostate Cancer
Does my pet have bladder or prostate cancer?
- Common symptoms include pain or abnormal posturing during urination, poor urine stream, and/or discolored or bloody urine.
- Diagnosis of bladder and prostate cancer can be challenging, and may involve a variety of tests, including X-rays, abdominal ultrasound, urinalysis, cytology, biopsy with histopathology, and sometimes even surgery.
- Almost all bladder tumors in dogs are a type of cancer called “transitional cell carcinoma” (TCC). These tumors grow from the lining of the bladder and/or urethra, and can spread throughout the lower urinary tract.
- Prostate cancer may be either TCC or prostatic carcinoma (PC). Unlike TCC, PC generally remains confined to the prostate, so may be more amenable (than TCC) to focused treatments like surgery or stereotactic radiation therapy (SRT).
- Unfortunately, it is impossible to distinguish between TCC and PC using cytology or histopathology. Doctors can use a combination of tests (ultrasound, cystoscopy, cytology, etc.) to get a better handle on whether a patient has TCC or PC.
What are the treatment options?
- The prognosis for bladder and prostate cancers varies widely between patients, and can be very difficult to predict for an individual dog. This section provides some general information about average prognoses associated with various treatments.
- Surgery: a useful treatment for some bladder and prostate tumors. It is best if surgery can be combined with drug treatments (see below; drug treatments address microscopic bits of tumor left behind at surgery, and can slow the spread of cancer to other organs).
- NSAIDs: drugs like piroxicam, Deramaxx® and Previcox™ have been shown to have anti-cancer effects. Your veterinarian may choose to use similar drugs, like carprofen or meloxicam. Average survival times with this treatment are about 6 months.
- NSAIDs plus Chemotherapy: The most common treatment for bladder and prostate cancer is a combination of an NSAID with injectable chemotherapy. Most of these chemotherapy drugs are well-tolerated by dogs, and given through an IV, once every 3 weeks. Average survival times with this treatment are about 10-11 months.
- NSAIDs plus Chemotherapy plus Radiation Therapy: Radiation therapy (IM/IGRT) is a new and exciting treatment available for bladder and prostate tumors. The average survival time in dogs treated with an NSAID plus chemotherapy and IM/IGRT is in excess of 20 months.
- Other options: some dogs with lower urinary tract tumors may benefit from procedures such as stenting, laser ablation, SRT or palliative-intent radiation therapy.
Types of radiation therapy:
- IM/IGRT: We deliver full-course radiation therapy using a relatively new technique called IM/IGRT (intensity-modulated and image-guided radiation therapy). 5 treatments per week are given for 4 weeks, with fewer side effects than possible using more conventional techniques. This treatment, in combination with NSAIDs and chemotherapy is currently considered the best possible treatment in most cases of bladder and prostate cancer.
- SRT Also commonly referred to as SRS (stereotactic radiosurgery), GammaKnife® or CyberKnife® treatment is the newest and most convenient treatment available for cancers of the urinary tract. Unfortunately, SRT is not appropriate for many dogs with cancers of the bladder, urethra and prostate. If you’re interested, be sure to ask your radiation oncologist whether they think SRT could be a safe and effective option for your pet.
- pRT Palliative-intent radiation therapy can be a good option for pet owners who would like to pursue a treatment that will make their pet feel better, but cannot afford IMRT or SRT.
Navigating the options:
||20 treatments, given once daily, 5 days a week (M-F)||3-6 treatments, usually given every other day.||4-6 treatments given either daily or once weekly.|
|Commonly used to treat:
||TCC of the bladder,
prostate and/or urethral tumors.
|Prostatic carcinoma||Bladder, prostate and/or
|Goal of treatment
||Induce a strong
remission, and provide best possible prognosis.
|Similar to IM/IGRT.||Improve quality of life.|
|Short-term side effects :||Uncommon, but can include hair loss over the abdomen, bloody diarrhea, and/or
discomfort during urination/defecation .
|Long-term side effects :||Up to 30% of patients may experience long term side effects such as pain of difficulty when urinating or defecating. These types of side effects typically develop months to years after RT, and can be difficult to manage.|
Facts about radiation therapy:
- Performed on an outpatient basis.
- Patients typically arrive at the hospital in the morning. Families are called and come pick their pet up after they have received that day’s treatment. This is often in the afternoon.
- If you are coming from a distance, talk with our nursing staff to discuss the logistics of having your pet board at the hospital during radiation therapy.
- Short-term side effects are usually mild and temporary.
- New radiation technologies and techniques have revolutionized treatment of bladder and prostate cancers, allowing for effective cancer treatment with few, if any, short term side effects.
- Some of the possible side effects of radiation therapy can cause temporary discomfort, but the doctors and nursing staff will make sure your pet is as comfortable as possible during and after treatment.
- Long-term side effects are possible, but quality of life is usually very good.
- Moderate to severe, progressive side effects can develop months to years after finishing RT.
- About 90% of pet owners report that their pet’s quality of life is stable or improved after finishing IMRT for bladder and prostate cancer. In fact, years after finishing RT, a large majority of pet owners report that they would still have opted to treat their pet’s tumor with radiation.