Bacillus Calmette–Guerin is a form of immunotherapy that doctors can use to treat some forms of bladder cancer. Following surgery to remove the cancer, this treatment can help prevent the cancer from returning.

In this article, we will discuss what Bacillus Calmette–Guerin (BCG) therapy is, when doctors use it, and what to expect during treatment.

We also cover side effects, alternative treatment options, and the outlook associated with bladder cancer.

What is BCG therapy?

bcg treatment for bladder cancer
Doctors may use BCG to treat some early forms of bladder cancer.

BCG is a bacterium similar to that which gives rise to tuberculosis (TB). However, BCG does not tend to cause serious illness. Doctors use it to vaccinate people against TB.

Doctors may also use BCG as a type of intravesical immunotherapy to treat some early forms of bladder cancer.

Immunotherapy works by encouraging a person’s immune system to attack and destroy cancer cells. Intravesical means that the treatment specifically targets the bladder.

Using a catheter, a healthcare professional will administer BCG into a person’s bladder in the form of a liquid drug. A catheter is a flexible tube that professionals can pass through the urethra into the bladder.

This method of delivery allows the drug to come into direct contact with the cancer cells in the bladder. This causes the immune system to target them and not other parts of the body.

BCG therapy is most effective in the early stages of bladder cancer. That is, before the cancer has spread to other parts of the body.

When do doctors use it?

A person will often undergo BCG immunotherapy within 24 hours of transurethral resection of bladder tumor (TURBT).

A TURBT is a type of surgery that doctors use to treat early-stage bladder cancers. Typically, this means either noninvasive (stage 0) or minimally invasive (stage 1) forms of the disease.

For people who have cancer that has gone deeper into the bladder or spread to other parts of the body, a doctor will recommend other treatment options.

During a TURBT, a surgeon attempts to remove all of the cancer cells from the bladder. The aim of BCG immunotherapy is to prevent the cancer from returning following a TURBT.

A person will usually have BCG immunotherapy once per week for 6 weeks. A doctor may recommend another 6 weeks of BCG if they feel it is required.

What to expect

bcg treatment for bladder cancer drinking water
It is vital to drink plenty of liquid after treatment to help flush the BCG from the bladder.

A healthcare professional will tell a person how best to prepare for BCG immunotherapy. They may ask the individual not to drink fluids for several hours before the procedure. They might also recommend that the person avoids consuming caffeine immediately after having BCG immunotherapy. This allows the drug to stay in the bladder for a longer period of time.

Immediately before the procedure, a person will usually empty their bladder. Then, to carry out the BCG treatment, a healthcare professional will numb the genital area and insert a catheter into the individual’s bladder. They will then inject the BCG drug into the bladder.

The healthcare professional will then either cap or remove the catheter to keep the liquid inside the bladder for a period of time. They may then ask the person to lay on their back and rotate from side to side. This movement helps the liquid reach all parts of the bladder.

During the treatment, a person will need to hold their urine for around 2 hours. After this, the healthcare professional will ask the individual to empty their bladder.

The BCG drug contains live bacteria that a person can pass to other people. It is therefore important to take precautions when urinating for 6 hours following the treatment.

Such precautions include:

  • drinking plenty of liquids to help flush the BCG from the bladder
  • sitting, not standing, when urinating
  • adding undiluted bleach and waiting 15 minutes before flushing
  • washing the hands and genitals thoroughly after urinating

Doctors also recommend using a condom during sex while receiving weekly BCG treatments. Women having BCG immunotherapy should also avoid becoming pregnant or breastfeeding until the treatment has ended.

After the initial 6 weeks, a doctor may recommend that a person continues to undergo regular BCG treatments for anywhere from a few months to 3 years.

Side effects

BCG immunotherapy can cause a number of side effects. It is common for people to experience flu-like symptoms, such as chills, fever, and fatigue, for 2–3 days following the treatment.

Other common side effects include:

Though rare, the BCG bacterium can spread outside of the bladder and cause an infection. When this occurs, a person may experience:

  • shortness of breath
  • dizziness
  • fever that does not respond to medications
  • confusion
  • joint pain
  • fatigue
  • a skin rash

If the infection spreads, it can lead to additional complications, such as:

People who experience symptoms of infection or any other serious side effects following BCG treatment should speak to their doctor immediately.

Alternative treatment options

bcg treatment for bladder cancer chemo
Chemotherapy is an alternative treatment option for bladder cancer.

There are many treatment options available for people with bladder cancer. A person should speak to their doctor about what treatment options are suitable for them.

A doctor will base their recommendations for treatment on several factors, including:

  • the stage of the bladder cancer
  • the type of bladder cancer
  • a person’s overall health and age
  • a person’s tolerance of certain treatments
  • the success of any previous treatments

Other treatment options for bladder cancer include:

A person may require a combination of different treatments to successfully treat their cancer.


The outlook for bladder cancer will depend on how early a doctor can diagnose and treat the disease.

According to the National Cancer Institute, the overall 5-year relative survival rate for bladder cancer is 76.8 percent. This means that people with bladder cancer are 76.8 percent as likely as people without it to live for at least 5 years following diagnosis.

Doctors typically use BCG immunotherapy to treat stage 0 and stage 1 bladder cancer. The 5-year relative survival rate for people with stage 0 bladder cancer is 95.4 percent. For people with stage 1 bladder cancer, this figure is 69.4 percent.

However, these figures are only estimates, and everyone’s outlook will be different. It is also important to note that doctors have based these figures on data from 2008–2014, and that cancer treatments are always continuing to improve.


BCG is type of immunotherapy for bladder cancer. Doctors typically use BCG to prevent cancer returning following TURBT in people with early-stage disease. BCG is not effective against bladder cancer that has spread to other parts of the body.

A healthcare professional will deliver the drug directly to the bladder using a catheter. A person will then need to hold their urine for 2 hours before emptying their bladder.

BCG is a type of bacterium. For several hours following the procedure, a person will need to take precautions when urinating to prevent passing the bacterium to other people.

Some people may experience flu-like symptoms for a few days after having BCG therapy.

In rare cases, BCG can spread to other parts of the body and cause an infection. Anyone who experiences signs of infection or serious side effects should speak to their doctor immediately.