Bacillus Calmette-Guerin (BCG) is the main intravesical immunotherapy for early stage bladder cancer. It’s made from a weakened strain of Mycobacterium bovis, a vaccine for tuberculosis.

Immunotherapy is used to prompt the immune system into attacking cancer cells. BCG is a liquid drug that can be deposited directly into your bladder through a catheter. Doctors have been using this method of treating superficial bladder cancer for 40 years.

Continue reading to learn more about BCG, how it’s used, and what you can expect of treatment.

BCG is appropriate for noninvasive (stage 0) and minimally invasive (stage 1) bladder cancers. It usually follows a procedure called transurethral resection of bladder tumor (TURBT). It’s intended to help prevent recurrence.

This treatment only affects cells inside the bladder. It’s not useful for later stage bladder cancer that has spread into or beyond the bladder lining, or to other tissues and organs.

It’s important that you follow your doctor’s instructions for what to do before and after the procedure. Tell your doctor about all the medications you take. Certain immunosuppressants, antimicrobial therapies, and radiation therapies can interfere with BCG treatment.

You’ll be advised to limit your fluid intake for four hours prior to the procedure. You might be told to avoid caffeine for a few hours longer than that, because it’s a diuretic and could make things more difficult.

You’ll be asked to urinate just before the procedure so you’ll be able to hold the medication in your bladder for several hours.

A urinary catheter is inserted through your urethra and into your bladder. Then the BCG solution is injected into the catheter. The catheter is clamped off so the solution stays in your bladder. Some doctors may remove the catheter at this time.

You have to hold the medicine in your bladder. You’ll be instructed to lie on your back and to roll from side to side to make sure the solution reaches your entire bladder.

After about two hours, the catheter is unclamped so the fluid can be drained. If the catheter was already removed, you’ll be asked to empty your bladder at this time.

You may be advised to drink plenty of fluid to flush the rest of the medication from your bladder.

For six hours after each treatment, you’ll have to be very careful when you urinate to avoid transmitting BCG to others. Men should urinate while seated to avoid splashing.

Disinfect the urine by adding 2 cups of bleach into the toilet. Let it stand for about 20 minutes before flushing. You should also wash your genital area very carefully after you urinate, so your skin doesn’t become irritated from the BCG. Wash your hands thoroughly, too.

Men can pass BCG to their partner during sex. For that reason, you should avoid sex for 48 hours after each treatment. Use a condom between treatments and for six weeks following your final treatment.

Women should avoid getting pregnant or breastfeeding while on BCG therapy.

Treatment is usually given every week for six weeks. After that, you might need to do it once a month for six months to a year.

One benefit of BCG is that while it affects the cells in your bladder, it doesn’t have a major effect on any other part of your body. But there can be a few side effects such as:

Tell your doctor if symptoms last more than a few days.

It’s rare, but BCG can spread through the body and cause a serious infection. Symptoms of this include:

Serious complications of this infection include inflammation of the lungs, hepatitis, and inflammation of the prostate and testicles. If you have any sign of serious infection, seek immediate medical attention.

BCG treatment is more effective than TURBT alone or TURBT with chemotherapy in preventing recurrence.

When comparing BCG to other bladder cancer treatments, it’s important to remember that treatment isn’t the same for everybody. Some of the factors that determine your options are:

  • type of bladder cancer
  • stage at diagnosis
  • your age and general health
  • how well you tolerate certain treatments

Cancer treatment usually involves more than one type of therapy, which can be given at the same time or one at a time. That makes it difficult to compare one treatment to another.

When it comes to BCG, it’s usually done following TURBT in early stage bladder cancer. BCG treatment may result in fewer side effects than systemic chemotherapy, which affects your entire body.

Sometimes, TURBT isn’t an option, as would be the case in later stage bladder cancer. Then it becomes necessary to remove part or all of the bladder. Chemotherapy or radiation therapy may also be recommended.

Each type of treatment has potential benefits and side effects to consider. Your doctor will help you work through your options and decide on the best treatment for you.

BCG has been used to treat noninvasive bladder cancer for a long time. It’s an effective way to get your own immune system to attack the cancer cells in your bladder without harming other tissues and organs. It’s generally well-tolerated.

Based on records from 2007 to 2013, the five-year relative survival rates were 95.7 percent for stage 0 bladder cancer and 70.1 percent for stage 1 bladder cancer.

Your doctor can give you a better idea of what to expect based on your personal medical profile.