The most common way to give this treatment for bladder cancer is intravesically. This means the medicines are put right into your bladder instead of injected into your blood. Early-stage bladder cancer can often be treated with the immunotherapy medicine called Bacillus Calmette-Guerin (BCG). BCG is put into your bladder through a catheter in your urethra. Your body’s immune system responds to BCG and is "turned on" to attack and kill the bladder cancer cells.

You go to your provider’s office or an outpatient clinic to have this done. For 4 hours before the treatment, you should not drink any liquids. Your bladder needs to be empty for BCG to work.

A soft thin catheter is put through your urethra into your bladder. This isn’t painful. But you’ll feel some discomfort when the catheter goes through your urethra. Any urine left in your bladder drains out through the catheter. Then the BCG is put through the catheter and into your bladder.

Sometimes the catheter is left in place. Then the BCG is drained out through it when treatment is over. In some cases, the catheter is removed after the BCG has been put into your bladder. Then you should do your best not to urinate for at least 2 hours. This lets the medicine to stay in your bladder long enough to activate your immune system to kill cancer cells. You’ll lie flat while the medicine is in your bladder. You’ll be asked to change position from time to time to make sure the medicine reaches all parts of the bladder lining.

Because BCG is made up of live bacteria, it’s important to follow instructions about handling your urine after treatment. Wash your hands after urinating. You may be told to add bleach to the toilet water for the first few hours after the treatment to kill the bacteria in your urine. 

You'll be told to drink a lot of water starting about 2 hours after the treatment. This will dilute the BCG that's left in your bladder. It will also help reduce bladder irritation, fever, and other side effects.

Most people have 6 weekly treatments at first. Follow-up treatment will be done over the next 12 to 24 months. Follow-up treatments may be given once a month or less often. For instance, you may get a treatment once every 3 months. These treatments are called maintenance BCG treatments. They help keep the cancer from coming back.

This means the immunotherapy medicine is given into your blood by IV (intravenously). The medicine can then go through your whole body. This is why it's used to treat cancer that has spread beyond the bladder.

Systemic immunotherapy is used to treat a lot of different cancers, but is fairly new as a bladder cancer treatment. A lot of research is being done on this. Some of the immunotherapy medicines now used for bladder cancer are:

• Atezolizumab
• Durvalumab
• Avelumab
• Nivolumab
• Pembrolizumab

These medicines target a protein that keeps immune system cells from killing cancer cells. When this protein is blocked, your immune system is able to stop tumor growth, make tumors grow slower, or kill cancer cells.

Systemic immunotherapy is usually given every 2 or 3 weeks. You can get it at your provider's office or an outpatient clinic. You don't have to stay in the hospital for this treatment.