American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a known increased risk associated with the use of cyclophosphamide?

1. Heart disease

2. Lung cancer

3. Bladder cancer

4. Kidney failure

The correct answer is: Bladder cancer

Cyclophosphamide is an alkylating agent commonly used in the treatment of various cancers and autoimmune conditions. One of the significant risks associated with its use is the development of bladder cancer. This risk is primarily due to the drug's metabolite, acrolein, which is known to cause damage to the urothelium—the bladder's lining. Prolonged exposure to this metabolite can lead to the formation of transitional cell carcinoma, a type of bladder cancer. Patients receiving cyclophosphamide are often monitored for signs of hematuria (blood in urine) as a potential indicator of bladder complications. Hydration and frequent urination protocols are sometimes implemented to help reduce the concentration of acrolein in the bladder and mitigate the risk. This well-documented association underscores the importance of screening and preventive measures for patients undergoing treatment with cyclophosphamide. While the use of cyclophosphamide may also carry risks for heart disease, lung cancer, and kidney failure, the specific and significant link to bladder cancer makes it a notable component of patient education and ongoing management strategies in those receiving this treatment.