BCG Instillation


What is BCG Instillation?
BCG Instillation, a form of intravesical immunotherapy, plays a role in the treatment of superficial bladder cancer. Intravesical refers to something occurring within the bladder. This procedure involves the administration of a substance called Bacillus Calmette-Guérin (BCG) directly into the bladder via a catheter.
BCG, initially developed as a vaccine for tuberculosis, is utilised in a weakened form in medical applications. Upon administration, it acts by stimulating the immune system to target and destroy cancer cells within the bladder.
This therapy is particularly effective against non-muscle invasive bladder cancers (superficial bladder cancer), such as carcinoma in situ (CIS) and other early-stage tumours that have not penetrated the bladder wall muscle. BCG is also employed to reduce the likelihood of cancer recurrence and the need for more invasive treatments like cystectomy. It is usually conducted following TURBT, a surgical procedure to remove visible cancer.
Pre-operative Preparations
Before undergoing BCG instillation, patients are required to follow specific guidelines to ensure the effectiveness of the treatment and to minimise risks.
- Fluid Restriction: Patients should limit fluid intake to reduce urine production, aiding in retaining the BCG solution in the bladder.
- Infection Check: A urine check for infections is conducted on the day of the procedure to ensure patient safety.
- Medical Consultation: Patients can discuss the procedure beforehand to address any concerns.
- Avoiding Certain Substances: Abstaining from caffeinated beverages and diuretics can help maintain an optimal bladder condition for the procedure.
- Bladder Emptying: Urination before the procedure is necessary to ensure the bladder is empty before instillation.
BCG Instillation Procedure
The procedure typically involves the following steps:
- Catheter Insertion: A catheter is inserted through the urethra into the bladder to administer the BCG solution.
- BCG Administration: The liquid BCG solution is introduced into the bladder through the catheter, which is then removed.
- Holding the Solution: Patients retain the BCG solution in the bladder for two hours to ensure adequate contact with the bladder lining.
- Positional Changes: Changing positions (lying on the back, stomach, sides) during the two hours helps distribute the BCG solution evenly in the bladder.
The BCG instillation procedure involves two phases: the induction phase, where BCG is administered weekly for six weeks to initiate the immune response against cancer cells, and the maintenance phase, which involves less frequent treatments to sustain the therapy’s effectiveness and reduce cancer recurrence.
Post-Procedure Care and Recovery
After BCG Instillation, patients should rest and avoid strenuous activities for a short period. Common post-procedure guidelines include staying hydrated, avoiding certain beverages like caffeine, and monitoring for any side effects, such as a burning sensation during urination, increased frequency of urination, or low-grade fever. Most side effects are mild and resolve within a few days.
Recovery time can vary, but patients usually resume normal activities within one to two days following treatment. Regular follow-up appointments can help monitor the treatment’s effectiveness and manage any potential complications.
Benefits of BCG Instillation
BCG Instillation offers several benefits in the treatment of early-stage bladder cancer, particularly when combined with TURBT.
Targeted Immunotherapy
BCG Instillation acts specifically on the bladder, minimising systemic side effects compared to oral or injectable chemotherapy. By delivering the treatment directly to the bladder through a catheter, BCG targets cancer cells without adversely affecting the rest of the body.
Reduction in Cancer Recurrence
The use of BCG has been shown to decrease the likelihood of bladder cancer recurrence. This is beneficial for patients with non-muscle invasive bladder cancer, where the risk of recurrence can be high.
Delay in Tumor Progression
BCG treatment can slow the growth of bladder tumours, thereby reducing the urgency for more aggressive treatments like cystectomy (bladder removal).
Conservation of the Bladder
By effectively managing early-stage bladder cancer, BCG Instillation allows for bladder preservation, which can help maintain quality of life.
Effective for High-Risk Cancers
BCG is particularly beneficial for treating high-risk tumours, such as carcinoma in situ (CIS), where it has shown considerable efficacy.
Long-Term Management
The maintenance therapy aspect of BCG treatment allows for long-term management of bladder cancer, which helps prevent both recurrence and progression.
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Potential Risks and Complications
While effective, BCG treatment, like all medical procedures, carries potential risks and side effects
- Common Side Effects: These may include bladder irritation, frequent urination, blood in urine, flu-like symptoms, and discomfort during urination.
- Systemic BCG Infection: Though rare, BCG can cause a systemic infection similar to tuberculosis, characterised by fever, joint or muscle pain, nausea, cough, rash, and fatigue.
- Infection Management: Immediate contact with your urologist is necessary if any symptoms of systemic infection or prolonged high fever occur.

Dr Lee Fang Jann
Dr Lee is a urologist and kidney transplant surgeon with a broad-based expertise of all urological disorders
He has subspecialty focus on men’s health and male infertility, and special interest in minimally invasive prostate enlargement therapy and kidney stone treatment. Dr Lee has received numerous awards for service excellence such as the Service With A Heart Award (2006-2008, 2011) and the Singapore Health Quality Service Award (2016).
- Bachelor of Medicine and Bachelor of Surgery (Singapore)
- Membership of The Royal College of Surgeons (Edin)
- Master of Medicine (Surgery) (Singapore)
- Fellowship of the Academy of Medicine (Urology)
- Clinical fellowship at Oxford Transplant Centre in the UK
Prior to entering private practice, Dr Lee served in the public sector for 16 years at SGH, where he initiated dedicated clinics evaluating and treating patients with complex men’s health and fertility issues. He also led the Renal Transplant Program and laparoscopic donor nephrectomy service as Surgical Director.
Apart from clinical work, Dr Lee is active in academia and believes in the importance of grooming the next generation of doctor. He was Senior Clinical Lecturer at NUS’ Yong Loo Lin School of Medicine and currently, Adjunct Assistant Professor at the Duke-NUS Medical School. Dr Lee is also regularly invited to share his experiences locally and regionally through lectures, workshops and surgical demonstrations.
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Frequently Asked Questions
How does BCG Instillation work?
BCG, a vaccine-like substance, is administered directly into the bladder through a catheter. It activates the immune system within the bladder, helping it to identify and attack cancer cells.
Who is eligible for BCG Instillation?
This treatment is typically used in patients with early-stage non-muscle invasive bladder cancer, particularly those with carcinoma in situ and other superficial bladder cancers.
What are the benefits of BCG Instillation?
BCG Instillation is effective in reducing the recurrence of bladder cancer and can delay the progression of the disease, allowing for bladder preservation and improved quality of life.
Are there risks associated with BCG Instillation?
While generally safe, BCG Instillation can have side effects like a burning sensation during urination, frequent urination, low-grade fever, and fatigue. More severe complications are rare but can occur.
How long does the BCG treatment last?
The initial treatment typically involves weekly instillations for six weeks, followed by a maintenance phase that can vary based on individual response.
What should I expect during recovery?
Most side effects subside within a few days. Patients are usually able to resume normal activities shortly after each treatment session, with specific recovery times varying individually.
Can bladder cancer recur after BCG Instillation?
While BCG Instillation reduces the risk of recurrence, bladder cancer can potentially return. Regular follow-up and monitoring can help lead to early detection and treatment of any recurrence.