Bacillus Calmette-Guerin (BCG)

Reviewed by: HU Medical Review Board | Last reviewed: April 2023

Bacillus Calmette-Guerin (BCG) treatment is a type of intravesical immunotherapy that can be used to treat people with bladder cancer. BCG is a type of bacteria that causes a reaction in a patient’s immune system that can destroy cancer cells located in the lining of the bladder.1,2

When it is delivered into the bladder, BCG attracts the body’s immune system cells and activates the cells, which then causes them to attack cancer cells in the bladder lining. BCG treatment in bladder cancer is known as local immunotherapy.1,2

How is BCG immunotherapy used to treat bladder cancer?

BCG intravesical immunotherapy is typically used to treat patients with early-stage bladder cancer. This includes stage 0 and stage I bladder cancers, in which the cancer cells have not spread beyond the lining of the bladder and into the muscle of the bladder wall.1,2

BCG is used for early-stage cancers because it only has an effect on cancer cells located in the bladder lining. It does not have an effect on bladder cancer cells that are located in the muscle of the bladder wall or on cancer cells that are in the urethra, kidneys, ureters, or other organs.1,2

When is BCG used?

BCG immunotherapy is often used after a patient has had a surgical procedure called transurethral resection of bladder tumor (TURBT). During this procedure, the surgeon removes the tumor in the lining of the bladder using a thin surgical instrument inserted into the bladder through the urethra, which is the tube-like organ that carries urine out of the body from the bladder.

When it is delivered after the TURBT procedure, the aim of BCG treatment is to destroy any remaining cancer cells in the lining of the bladder, and to attempt to keep bladder cancer cells from growing back.

Maintenance BCG therapy

For some patients with certain types of tumors in the bladder lining, healthcare providers may recommend maintenance therapy using BCG. Maintenance therapy is used long term after the patient’s initial treatment for bladder cancer (surgery, for example) to potentially help reduce the chance that bladder cancer cells will recur, or start growing again after treatment.

What happens during BCG treatment?

BCG is an intravesical treatment for bladder cancer. Intravesical means that the liquid medicine is delivered directly into the bladder through a catheter, which is a thin tube inserted into the urethra. By inserting the medicine directly into the bladder, it only affects the bladder lining and does not affect other parts of the body that do not need treatment.1

In patients who receive BCG treatment after a TURBT procedure, BCG immunotherapy treatment typically starts a few weeks after the surgery. Patients generally receive treatment once per week for six weeks. Patients receiving BCG immunotherapy for maintenance treatment may receive treatment over a longer period of time.

What are the possible side effects of BCG?

Some patients treated with BCG immunotherapy may experience side effects. Common side effects include flu-like symptoms, fatigue, fever, chills, or bladder irritation. Speak with your healthcare provider if you experience these types of symptoms. In rare cases, patients treated with BCG treatment can develop a serious infection that needs to be treated right away. Contact your healthcare provider immediately if you experience a high fever.1,2

Some people who receive maintenance therapy with BCG immunotherapy over a longer period may experience bladder irritation, bleeding, or fever. If you experience these types of symptoms, let your healthcare provider know.

These are not all the possible side effects of BCG immunotherapy. Talk to your doctor about what to expect with BCG immunotherapy. You also should call your doctor if you have any changes that concern you about this treatment.

Before beginning treatment for bladder cancer, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.

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