BCG Treatment For Bladder Cancer Patient Information

What is bladder cancer

The bladder is a hollow sac-like structure that sits at the very bottom of the abdomen (tummy). It stores urine which is produced by the kidneys until this urine is passed out when we pee. 

The kidneys, ureters, bladder, and urethra make up the urinary tract. Urine is formed in the kidneys, then moved along to the bladder by way of the ureters. The bladder is expandable, and it is able to store urine until it is ready to be passed out through the urethra.

Cancer of the bladder usually starts in the cells which line the inside of the bladder. The condition typically affects older adults and is more prevalent in men. People over the age of 60 are most commonly diagnosed with bladder cancer. It is responsible for 3% of all cancer diagnoses worldwide.¹

Types

Bladder cancer is staged according to the degree of spread of cancer:

• Non-muscle invasive - This is an early form of bladder cancer. The cancer cells are limited to the inner lining of the hollow bladder. They have not spread to involve deeper layers of the bladder wall

• Muscle invasive - In this stage, the cancer cells have spread beyond the inner lining of the bladder. They are found in the muscle layer of the bladder wall

• Metastatic bladder cancer - This is an advanced form; the cancer cells have spread beyond the bladder wall to other body organs. Common sites for the spread of bladder cancer include the lungs, the bones, and the brain

Stages

Bladder cancer is staged using the TNM system; where T characterizes the tumor, N describes lymph node involvement, and M denotes the presence or absence of metastasis.

TNM staging is relevant to treatment, as different treatment modalities are used for different cancer stages.

The tumor is staged as follows:

• Ta and Tis tumors are confined to the inner lining of the bladder and do not invade the bladder wall
• T1 tumors spread beyond the inner lining of the bladder but do not invade the muscle
• T2 tumors invade the bladder wall muscle

•  T2a tumors - invade superficial bladder wall muscle
•  T2b tumors - invade deep bladder wall muscle

• T3 tumors extend beyond muscle into the layer of fat that surrounds the bladder
•  T4 tumors extend into other surrounding organs like the prostate and the vagina. Tumors that extend to the wall of the tummy are also classified as T4

Lymph node staging:

• N0 - no lymph node involvement
• N1 - cancer cells in a single pelvic lymph node
• N2 - cancer cells in more than one pelvic lymph node
• N3 - cancer cells in lymph nodes outside the pelvis

Metastasis staging:

• M0 - no metastasis (spread) of cancer outside the pelvis
• M1 - the presence of metastasis outside the pelvis

Risk factors

Several risk factors for bladder cancer have been identified. These include:

• Smoking - Cigarette smoking is the strongest risk factor for bladder cancer; it causes about 50-65% of all cases. Specific substances,like beta naphthylene, in cigarettes have been identified as some of the causes of bladder cancer^1,2

The association between smoking and bladder cancer is so strong that even secondhand smoke has been found to be a risk factor for the condition³

Smoking cessation reduces the risk of the disease but it does not fully eliminate it, as people who have smoked in the past have a higher risk of developing bladder cancer than people who have never smoked³

• Opium - The use of opium - which is derived from the poppy plant - has been linked to the development of several cancers including bladder and lung cancer. Both ingested and smoked forms of opium have been implicated⁴

• Occupational exposure - Exposure to aromatic amines has been strongly linked to bladder cancer. These substances are found in products such as, plastics, hair, other dyes, paints, and cement. People who work in industries where they are exposed to these substances repeatedly have a higher risk of developing bladder cancer than their non-exposed counterparts⁵

4,4 - methylenebis (2-chloroaniline) which is widely used to manufacture polyurethane parts also causes bladder cancer. Occupational exposure to this increases bladder cancer risk⁵

Firefighters are exposed to substances that can cause a wide range of cancers in the line of duty. These include some of the substances mentioned above; their bladder cancer risk is also, therefore, heightened.⁵

• Other substances - arsenic is naturally occurring and is found in the air, water, and land. Inorganic arsenic is highly toxic, and has been linked to bladder cancer. It can be found as a contaminant in drinking water from ground sources, and from other sources like food and tobacco⁵

Chlorine is a chemical used to purify water and make it suitable for human consumption. Long-term ingestion of chlorinated water has been linked to the development of bladder cancer.⁶   

• Infectious causes -  Certain infections have also been linked to bladder cancer. Schistosomiasis (bilharziasis), a urinary tract infection with Schistosoma haematobium, is a well-known cause of bladder cancer. It commonly causes the condition in parts of Africa and the Middle East where infections abound^1,7

Human Papillomavirus (HPV) infections (especially HPV 16) which are mostly sexually transmitted, have been linked to bladder cancer.⁸

• Drugs - Certain drugs like the (now banned) pain reliever phenacetin, have been associated with bladder cancer. Cyclophosphamide, a drug used to treat other types of cancer, also has this association

What is BCG treatment?

BCG, which stands for Bacillus Calmette-Guerrin, is derived from a strain of Mycobacterium bovis, the organism that mostly causes tuberculosis in cattle. The organism is processed in such a way that its ability to cause harm is weakened, and it is manufactured into a liquid drug.

BCG is a live vaccine that is given to people to protect them from tuberculosis. It has also been found to be useful as immunotherapy for bladder cancer. For bladder cancer treatment, a weakened form of the vaccine is given intravesically (into the bladder).

It is used in specific forms of bladder cancer and involves the instillation of the drug into the bladder through the urethra with the aid of a catheter. This stimulates the immune system to attack the cancer cells and destroy them.

Intravesical immunotherapy with BCG has been found to be effective at preventing bladder cancer progression and recurrence.⁹

Other bladder cancer treatment options include chemotherapy, radiation therapy, and removal of some or all of the bladder (partial or radical cystectomy).

Types of intravesical treatment

BCG treatment is given in two phases :

1. Induction phase - entails weekly intravesical instillations of BCG for a period of 6 weeks
2. Maintenance phase - If it is determined that there has been a good response to the initial therapy the maintenance phase is commenced. It involves weekly BCG treatments for 6 week periods every 3 months for one to three years

Other agents that are used intravesically for bladder cancer include Mitomycin C, epirubicin, and gemcitabine

When is it used?

BCG treatment is usually used for bladder cancer treatment after the surgical removal of visible cancer which is carried out through the urethra. A procedure called transurethral resection of bladder tumor (TURBT). 

What type of bladder cancer is it used to treat?

BCG treatment is used to treat non-muscle invasive bladder cancer, as it is only useful in  cancers that have not invaded the bladder wall. It is also not useful in metastatic bladder cancer.

Having BCG treatment

The treatment is given on an outpatient basis. After applying a numbing agent, your healthcare provider will pass a tube called a urethral catheter into your bladder through the urethra. 

BCG is subsequently introduced into the bladder via the catheter. It is vital for the BCG to reachall parts of the bladder, so you might be asked to lie on your back, on each side, and on your tummy in turns for a few minutes each. You might also be asked to walk around for a bit. 

Typically, BCG is left in the bladder for 2 hours. After this time, it can be drawn out through the catheter, or you can pee it out. The catheter is removed before you leave the health facility.

Before the procedure, you might be asked to limit your fluid intake to ensure you don't have too much urine in the bladder, as this may interfere with the treatment.

Side effects

Common side effects of BCG treatment are mostly due to irritation of the bladder. These include:

• Pain on urination
• Blood in the urine
• A frequent need to urinate
• Fever
• Joint and muscle pain

These typically resolve on their own after 2-3 days.

 More serious side effects that could occur include:

• A high fever that does not resolve after a few days
• A cough

Contact your healthcare provider if you develop any of the above more serious side effects.

Sex after BCG treatment

BCG can remain in body fluids after treatment. To avoid passing it on to your partner, it is advisable to abstain from sex for 48 hours after each treatment. You should also wear a condom during sex for a week thereafter, and 6 weeks after treatment has ended. This protects sexual partners from any residual BCG that is present in seminal or vaginal fluid.

Prevention of bladder cancer

• Avoid smoking: If you are a smoker, speak to your healthcare provider about the resources available to help you quit
• Personal protection: If you work in an industry where you are potentially exposed to substances that can cause bladder cancer, ensure you follow all safety protocols and wear protective gear
• Stay hydrated: Drinking adequate amounts of water daily might help prevent bladder cancer
• Keep fit: Maintain a normal weight and ensure you exercise regularly

Conclusion

Bladder cancer is a serious but potentially preventable medical condition. Several risk factors have been identified, and avoiding the previously stated factors could help provide protection.

Non-invasive forms of bladder cancer are amenable to local therapy. BCG treatment is commonly used for such forms with generally favorable results. Common side effects of the treatment are often minor and resolve on their own after a few days.

Other treatment modalities for bladder cancer are available, your healthcare provider will help you decide which form of treatment is best for you.