Question

Agent of choice for intravesical therapy for carcinoma in situ of the bladder following endoscopic treatment is

• A. BCG
• B. Mitomycin
• C. Adriamycin
• D. Thiotepa

Hint:

Think about the intravesical agent that works by stimulating a local immune response rather than direct cytotoxicity.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks which drug is instilled directly into the bladder after endoscopic resection of carcinoma in situ (CIS), a flat, high-grade lesion confined to the urothelium that carries a high risk of progression to invasive disease.

Step 2: Key Concept or Approach:
Intravesical therapy after transurethral resection aims to eliminate residual tumour cells and reduce recurrence/progression. Agents used are either chemotherapeutic (direct cytotoxic action) or immunotherapeutic (stimulate a local immune response). For CIS specifically, an immune-mediated agent gives the best long-term response and reduces progression to muscle-invasive disease.

Step 3: Working Through the Options:
BCG (Bacillus Calmette-Guerin) attaches to the urothelium and triggers a local inflammatory/immune reaction (macrophage and T-cell activation) that clears residual and dysplastic urothelial cells, giving it the highest complete-response rate of any intravesical agent for CIS. Mitomycin C is a chemotherapeutic agent commonly used for low-to-intermediate risk superficial tumours to cut recurrence, but it is less effective than BCG for CIS. Adriamycin (doxorubicin) is an older intravesical chemotherapeutic agent with modest efficacy and is not preferred for CIS. Thiotepa is one of the oldest intravesical agents, limited by systemic absorption and myelosuppression, and is rarely used now.

Step 4: Conclusion:
Intravesical BCG is the agent of choice for carcinoma in situ of the bladder following endoscopic resection.