Bacillus Calmette-Guérin (BCG) Tice is a biological therapy. It is a form of immunotherapy that leverages the body’s own immune system to target and address certain medical conditions. This treatment involves introducing a modified bacterial strain to stimulate an immune response, aiming for therapeutic effects. BCG Tice is a specific preparation used to manage particular diseases.
Understanding BCG Tice
BCG Tice is an attenuated, live culture preparation derived from the Bacillus Calmette-Guérin (BCG) strain of Mycobacterium bovis. The original BCG strain was developed at the Pasteur Institute, resulting in a weakened, non-disease-causing form. The “Tice” designation refers to a particular strain of this weakened bacterium, developed at the University of Illinois from the original Pasteur Institute strain.
This preparation consists of live, weakened mycobacteria that can trigger an immune response without causing illness. The freeze-dried product contains a specific number of colony-forming units (CFU) of Tice BCG, typically ranging from 1 to 8 x 10^8 CFU per vial, which is approximately 50 mg wet weight.
How BCG Tice Is Used
BCG Tice is primarily utilized in the treatment of non-muscle invasive bladder cancer (NMIBC). This cancer is confined to the innermost layers of the bladder lining and has not spread to deeper muscle walls or other parts of the body. It is administered after transurethral resection of bladder tumor (TURBT), a surgical procedure that removes visible tumors from the bladder.
The main purpose of BCG Tice is to prevent the recurrence of bladder tumors and to stop or delay their progression to more invasive stages. It is recommended for high-risk NMIBC, including carcinoma in situ (CIS), a type of bladder cancer that remains on the bladder lining, and certain stage Ta and T1 papillary tumors.
How BCG Tice Works in the Body
The precise mechanism by which BCG Tice works against bladder cancer cells is not fully understood, but it is known to stimulate a localized immune response within the bladder. After being instilled into the bladder, the live BCG attaches to the urothelium, including cancer cells.
The presence of BCG in the bladder triggers an inflammatory reaction, which recruits various immune cells to the area. These immune cells include:
CD4+ and CD8+ lymphocytes
Natural killer (NK) cells
Granulocytes
Macrophages
Dendritic cells
These activated immune cells, along with the release of cytokines and chemokines, work to destroy cancer cells directly or indirectly. The immune response aims to eliminate remaining cancer cells and establish an immune memory to prevent future recurrence.
Administration and Expected Reactions
BCG Tice is administered directly into the bladder through a thin tube called a catheter, a procedure known as intravesical instillation. Patients are typically instructed to empty their bladder completely before the solution is instilled. The medication is then held in the bladder for approximately two hours, and patients may be asked to change positions every 15 minutes to ensure the solution coats the entire bladder lining.
A common treatment schedule involves one dose per week for six consecutive weeks, which is referred to as the induction course. Following this, monthly maintenance doses may be given for six to 12 months or potentially longer, extending up to two years.
During and after treatment, patients may experience common side effects, such as bladder irritation, including burning or pain during urination, increased frequency and urgency to urinate, and sometimes blood in the urine. Flu-like symptoms like fever, chills, malaise (general discomfort), and fatigue are also commonly reported, typically beginning 4 to 6 hours after instillation and lasting 24 to 72 hours. These irritative symptoms may increase in severity with successive administrations.
Patients are advised to drink extra fluids for several hours after treatment to help flush the bladder. For about six hours after treatment, urine will contain some live bacteria, so patients should sit to urinate to avoid splashing, and disinfect the urine with an equal amount of household bleach before flushing.