Bisphosphonates and metastatic breast carcinoma

BACKGROUND. Metastasis to the skeleton occurs in approximately 75% of patients with advanced breast cancer. It is the cause of much morbidity and decreased quality of life in these patients. METHODS. Zoledronic acid (Zoledronate) is a new, potent third-generation bisphosphonate that has recently been approved by the U.S. Food and Drug Administration for the treatment of both osteolytic and osteoblastic bone metastases. A Phase 3 clinical trial comparing the efficacy of Zoledronic acid 4 and 8 mg compared with Pamidronate 90 mg every 3-4 weeks has been completed. RESULTS. A 15 minute infusion of 4 mg of zoledronic acid is at least as effective as 90 mg of pamidronate in preventing skeletal complications in patients with metastatic breast cancer. CONCLUSIONS. Bisphosphonate treatment can delay skeletal events in patients with breast carcinoma that is metastatic to bone. Future trials will build on the results achieved with bisphosphonate treatment.