Immunotherapy represents a category of cancer treatments designed to empower the body’s own immune system to combat malignant cells. Bacillus Calmette-Guérin (BCG) is a widely utilized form of immunotherapy specifically for bladder cancer. This article aims to provide an overview of what BCG immunotherapy involves for individuals diagnosed with bladder cancer.
What is BCG Immunotherapy
BCG is an attenuated, or weakened, strain of Mycobacterium bovis, a bacterium closely related to the one that causes tuberculosis. Bladder cancer is currently the only cancer for which BCG is routinely used.
BCG is specifically employed to treat non-muscle invasive bladder cancer (NMIBC), which is cancer found only in the lining of the bladder and has not yet spread into the muscle wall or beyond. The treatment works by being directly introduced into the bladder, initiating a localized immune response. This stimulation helps the immune system to recognize and attack cancer cells within the bladder, reducing the risk of cancer recurrence and progression.
The mechanism involves BCG attaching to the bladder wall, and then being internalized by cells. Once inside, it triggers the release of various immune signaling molecules, which recruit immune cells to the bladder. These activated immune cells then target and destroy the bladder cancer cells.
Receiving BCG Treatment
BCG treatment is administered directly into the bladder through a method known as intravesical instillation. A catheter is inserted into the urethra and guided into the bladder. The liquid BCG solution is then delivered through this catheter.
A typical treatment schedule often begins with an “induction” phase, which usually involves weekly instillations for six weeks. After this initial phase, if the bladder is found to be tumor-free during follow-up, a “maintenance” phase may be recommended. This maintenance therapy involves less frequent treatments, often once a week for three weeks, repeated every 3 to 6 months for up to 1 to 3 years.
During the procedure, patients are often asked to hold the BCG solution in their bladder for approximately one to two hours to allow sufficient contact with the bladder lining. After this time, the solution is voided. To optimize treatment, patients may be advised to limit fluid intake before the instillation.
Managing Side Effects and Follow-Up
Patients undergoing BCG treatment commonly experience side effects, such as bladder irritation and systemic flu-like symptoms. Bladder-related symptoms can include frequent urination, an urgent need to urinate, discomfort or burning during urination, and sometimes blood in the urine. These symptoms are usually most noticeable in the first 24 to 48 hours and typically resolve on their own.
Systemic side effects often resemble the flu, with symptoms such as fever (usually below 101.5°F), chills, fatigue, and general malaise. These can last for about two to three days after treatment. Over-the-counter medications can help manage mild fever and discomfort. If symptoms become intense, last longer, or if a fever exceeds 101.5°F, seek medical attention, as these could indicate a more serious reaction or infection.
Regular follow-up surveillance is an important component of long-term management after BCG treatment. This monitoring typically involves periodic cystoscopies, which allow a doctor to visually inspect the bladder. Urine cytology tests, which examine urine samples, are also often performed. This ongoing surveillance helps detect any potential cancer recurrence early, allowing for timely intervention and further treatment.