BCG Therapy Safety

Last Modified: December 7, 2008


Dear OncoLink "Ask The Experts,"

I want to visit my mother, but her husband is undergoing BCG Vaccine treatment for bladder cancer. They are 87 and 85 years old, and do not use the best hygiene measures. I am concerned about my own health, as a 2-year breast cancer survivor. Am I at any risk while being in their home? Thank you for your help.


Michael Vozniak, PharmD, BCOP, Hematology/Oncology Clinical Pharmacy Specialist, responds:

BCG, or bacillus Calmette-Guerin, is a vaccine that is made from bacteria. It is a non-specific immunomodulator, which means that it stimulates the body's immune system. BCG has shown positive re sults when instilled into the bladders of certain patients with superficial bladder cancers who are felt to be at high risk of disease recurrence after surgical treatment alone. Superficial bladder cancers are only a few cell layers thick and are confined to the inner lining of the bladder, and so the BCG (or other drugs instilled directly into the bladder) can be absorbed into the superficial layers of the bladder and thus should reach all of the cancer cells.

BCG is placed into the bladder using a catheter, and left in the bladder for up to 2 hours. The catheter is left in place and clamped off to allow the bladder to be adequately exposed to the BCG. After two hours, the clamp is removed and the BCG is drained out. Because it is a live vaccine, it is recommended to pour liquid bleach into the toilet for up to 6 hours after receiving the medication in order to kill the vaccine. Pour 2 cups of bleach into the toilet and allow it to sit for 15 minutes before flushing. The patient should drink plenty of fluid in the hours/day after the treatment to flush the bladder. The treatment is given once weekly for 6 weeks, and may be repeated if necessary in the future.

Of note, men having this treatment can pass on BCG to their partners during sexual intercourse. To protect the partner from exposure to BCG, patients should not have sex for 48 hours after each treatment. A condom should be used at other times during the six weeks of treatment and for six weeks after treatment has ended.

There should be no risk to you if the bathroom is cleaned the day of administration, or alternatively, if you did not share a bathroom.

A good resource on bladder cancer treatments:

Bladder Cancer WebCafé


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