BCG for bladder cancer
BCG is the oldest immunotherapy in routine cancer care: a live, weakened strain of the Mycobacterium bovis bacterium instilled directly into the bladder to treat non-muscle-invasive bladder cancer. Given through a catheter after surgical removal of the tumor, it lowers the risk of the cancer coming back. Decades of use have made it a standard option described in NCI treatment summaries.
How it works
After the visible tumor has been removed through the urethra, a liquid containing BCG bacteria is placed into the bladder through a thin catheter and held there for a time before being passed with the urine. The NCI describes such intravesical treatment as flushing the bladder with drugs that kill cancer cells remaining after surgery, which lowers the chance of recurrence.
The bacteria do not attack the tumor directly. Their presence provokes a strong local immune reaction in the bladder lining: immune cells flow into the area and, while responding to the bacteria, also destroy residual cancer cells. Treatment is usually given as a series of weekly instillations, sometimes followed by maintenance doses; because live bacteria are present in the urine for a short time after each session, patients receive specific hygiene instructions.
Used in
Urinary Bladder
C67
standard intravesical treatment for high-risk non-muscle-invasive tumours