American Board of Internal Medicine (ABIM) Certification Practice Exam

A patient with bone metastases from breast cancer should be started on?

1. Zoledronic acid infused every three months

2. Denosumab injected every four weeks

3. Calcium and vitamin D therapy

4. Radiation therapy targeted at the bone

The correct answer is: Zoledronic acid infused every three months

In the management of bone metastases from breast cancer, the administration of bisphosphonates such as zoledronic acid is a standard approach. Zoledronic acid is effective at reducing skeletal-related events (such as fractures, pain, and the need for radiation) associated with bone metastases. It works by inhibiting osteoclast-mediated bone resorption, thereby helping to stabilize bone density and alleviate pain. The recommendation for zoledronic acid infusion every three months aligns with current best practices for patients with metastatic breast cancer, as it provides a convenient dosing schedule while effectively managing symptoms and preventing complications related to bone metastases. While denosumab is another alternative that targets the RANKL pathway to inhibit osteoclast activity, it is usually administered more frequently than every three months and is often considered in situations where bisphosphonates are not suitable. Calcium and vitamin D supplementation is important for overall bone health but does not specifically address the complications arising from bone metastases. Radiation therapy, while effective for localized bone pain, is typically reserved for specific, symptomatic lesions and does not have the long-term preventive benefits offered by bisphosphonates or denosumab in a metastatic context.