Efficacy and safety of intravenous bisphosphonates in patients with bone metastases caused by metastatic breast cancer

Solid tumors frequently metastasize to bone. This results in debilitating skeletal complications such as intractable bone pain, pathologic fractures, spinal cord compression, and hypercalcemia. Patients frequently require palliative radiation therapy or orthopedic surgery. Bisphosphonates have been shown to delay the incidence and decrease the frequency of skeletal-related events. Zoledronic acid is the only bisphosphonate that has provided benefits for patients with bone metastases secondary to a broad range of solid tumors. Among patients with metastatic breast or prostate cancer, zoledronic acid has demonstrated significant reductions in pain and skeletal morbidity compared with placebo. Zoledronic acid has also shown significant reductions in skeletal morbidity in patients with lung cancer or other solid tumors compared with placebo. Zoledronic acid is generally well tolerated. Flu-like symptoms which are manageable with standard treatment can occur. Renal monitoring is recommended, with dose reductions for patients with renal dysfunction. Osteonecrosis has been reported in patients receiving bisphosphonates and might be avoidable with appropriate dental care.