Intravesical BCG Therapy
Bacillus Calmette-Guerin (named after the bacterial type and the original investigative scientist) is a live tuberculosis bacteria that was originally used in the 1920’s (and still today) as a vaccine to prevent tuberculosis.
In the mid 1970’s, BCG was reported to have anti-tumor effects against TCC or transitional cell carcinoma (the most common type of cancer occurring in the bladder). When TCC is directly exposed to BCG, an immune response is stimulated, one that has the potential to kill the cancer cells. In order to treat a patient, the BCG is placed directly into the bladder through a catheter. The BCG used is called a “live-attenuated strain”. This means that the bacteria are live but greatly weakened so as to minimize the chance of causing TB in the treated patient. There are many theories as to why BCG works against TCC in the bladder. Although the mechanism is not fully understood, it is known that the BCG activates a specific part of the immune system called T-cells. These cells are important in fighting many types of infections and cancers.
BCG may be used for three different reasons in the bladder.
1. Kill remaining bladder tumour cells that may still exist after the primary tumour has been surgically removed.
2. Prevent new tumours from forming after all known tumour cells have been cleared from the bladder.
3. Decrease the incidence of progression (advancement to a higher stage of bladder cancer).
Patients in whom BCG should not be used
b. Patients taking certain drugs for Rheumatoid Arthritis (TNF inhibitors such as Remicade)
2. Previous serious complications from BCG
3. Patients taking warfarin (BCG less effective here)
4. Very elderly (may not have an adequate immune response)
There is no particular preparation for BCG therapy. If you are currently sick (ie. a severe cold or flu) or have gross haematuria (blood in the urine that you can actually see), you must tell the nurse as BCG will not be administered under those conditions. Before the BCG is administered, you must have a urine culture to be certain no infection is present. At the hospital, a strict protocol is followed whereby you will have regular urine tests throughout your treatment. BCG will not be given if a bladder infection is present.
The actual procedure typically takes just a few minutes. The initial treatment of BCG is once a week for six consecutive weeks. Some patients will benefit from further treatment, called “BCG Maintenance”. This generally consists of 3 weekly instillations each 6 months for a period of 1-2 years.
You will lie down on your back on a bed. Under sterile conditions, a small, soft catheter will be gently advanced into your urethra and into your bladder. All of the urine in your bladder will be emptied. Once your bladder is empty, the BCG medicine will be slowly poured into the catheter through a large syringe or funnel attached to the catheter. The medicine is allowed to slowly run into the catheter until it is all administered. The amount is small and is usually far less than the volume capacity of your bladder. The catheter is then slowly and gently removed. Alternatively, the catheter may be left in place and clamped.
It is important for you to hold the medicine in your bladder for as close to two hours as possible so that the medicine can remain in contact with the inner tissue lining of the bladder for that amount of time. If you typically have a problem holding urine for that long, you may want to limit fluid consumption for a few hours prior to the treatment. Certainly, beverages containing caffeine (coffee, tea, etc.) should be avoided that day prior to your appointment. These drinks will make you have to urinate more frequently.
It is important for you to understand the discard precautions for the first time you urinate after the treatment each week. Both men and women must sit on the toilet to urinate so that the BCG medicine does not splash anywhere but in the water. The toilet is then immediately flushed. Afterward, bleach should be poured into the toilet and allowed to remain for a couple of minutes while the sides of the toilet are gently cleaned. Do not put your hands in the water to clean. The toilet is then flushed again.
You might have a little stinging in the urethra the first time you urinate. This is usually due to the catheterization and is not a cause for concern. Each week, the stinging may last a bit longer than the prior week. This is due to cystitis (inflammation of the bladder wall) and/or urethritis (inflammation of the urethra). Although the sensation can last for two or three urinations after several weeks of treatment, it is rare for it to persist beyond the day of the treatment. In 25% of patients, there may be a little blood in the urine with the first few urinations after each treatment. It will typically resolve in one to two days. If the urine is not clear to the eye by the next week, the following treatment will be delayed. Perhaps 20% of patients may have minor flu-like symptoms the day of the treatment. They include fatigue, muscle aches, and maybe even a low grade fever. Again, these symptoms usually resolve in 24 hours. If you feel feverish, you should take your temperature. Any temperatures equal to or above 38 degree should be immediately reported to the doctor.
Possible Complications of the Procedure
The majority of patients will not experience any problem after BCG therapy. However, any procedure, regardless of complexity or time, can be associated with unforeseen problems. They may be immediate or even quite delayed in presentation. These may include, but are not limited to:
- Urinary Tract Infection or Urosepsis (Bloodstream Infection)
Even from a minor and sterile procedure, it is possible for you to get an infection with bacteria that typically cause urinary tract infections (UTIs). It may be a simple bladder infection that presents with symptoms of burning urination, urinary frequency and a strong urge to urinate. This will usually resolve with a few days of antibiotics. If the infection enters the bloodstream, you might feel very ill. This type of infection can present with both urinary symptoms and any combination of the following: fevers, shaking chills, weakness or dizziness, nausea and vomiting. You may require a short hospitalisation for intravenous antibiotics, fluids, and observation. This scenario is more common in diabetics, patients on long-term steroids, or in patients with disorders of the immune system.BCG sepsis is different. This is an infection that is not caused by the more common bacteria that typically cause UTIs. This describes a serious infection due to the instilled BCG agent itself, and it can occur in 1-3% of patients undergoing this type of therapy. BCG infection requires immediate hospitalisation and treatment with very specific antibiotic agents.
If you have high temperatures or any symptoms of severe illness (fevers, shaking chills, weakness or dizziness, nausea and vomiting, confusion) let your doctor know immediately and proceed to the nearest emergency room
- Blood or Blood Clots in the Urine
As previously mentioned, BCG can cause cystitis (inflammation in the bladder). Severe inflammatory changes in the bladder can result in haematuria (blood in the urine). In almost all instances, the urine clears on its own over the next day or so. If severe, the blood can form clots and block the flow of urine. This is more common in men who may already have partially obstructing prostates. The treatment may be placement of a catheter to drain the urine from the bladder and/or irrigating the clots out of the bladder.
- Urinary Retention
Even in the absence of bleeding in men, the prostate can become inflamed secondary to delayed infection. As a result, the flow of urine can be blocked. In this instance, a catheter is placed and your doctor would discuss the next step. Patients at greater risk are those who already have difficulty urinating before the procedure due to BPH (Benign Prostatic Hyperplasia).
- Urethral Strictures
Strictures are narrow, scarred tissue areas. Although uncommon, any patient who is catheterized often can develop scar tissue months or years later. Strictures are typically treated with minor, minimally invasive procedures.
- Bladder Contractures
Intravesical BCG kills tumour cells by stimulating an aggressive inflammatory response within the bladder. This inflammation can lead to shrinkage and stiffening of the bladder. In very rare cases, this may ultimately result in a bladder that is no longer functional and that may need to be removed.
Please contact Dr Sved’s office within 3 days of completion of your course of treatment. You may be seen in his offices at RPA, Bankstown or Strathfield Private Hospital. In the long term, regular cystoscopies and urine tests will be required to look for any sign of cancer recurrence.