Bone-modifying agents include a variety of medications and therapeutic agents that prevent or treat damage from bone metastases in patients with cancer. The primary purpose of these agents is prevention of skeletal events, such as pathologic fracture, spinal cord compression, and hypercalcemia. In addition, bone-modifying agents may affect chronic pain from bone metastases. Bisphosphonates, denosumab, pamidronate, and zoledronic acid are examples of bone-modifying agents.