Role of bisphosphonates in prevention and treatment of bone metastases from breast cancer.

Clinical research over the last decade has confirmed the helpful role of bisphosphonates in the management of patients with bone metastases secondary to breast cancer and other malignancies. This role is also expanding in myeloma and in the management of osteoporosis. Current clinical research in oncology is focusing on their potential for the prevention of skeletal complications of malignant disease and the development of bone metastases while basic researchers are developing compounds of higher potency and, perhaps, higher therapeutic efficacy. One of the earliest agents to be investigated, etidronate, is effective in the management of malignant hypercalcemia and, when used orally and intermittently, results in reduced bone loss in osteoporosis. However, it does not appear to reduce pain in patients with malignant disease. Clodronate has been shown to be an effective agent in the management of hypercalcemia and can be used as a single intravenous infection for this purpose. Clodronate is also effective in some patients in reducing bone pain and improving mobility. When used orally, it can, as can pamidronate, reduce the skeletal complications of breast cancer such as hypercalcemia, bone fractures and bone pain. It may have fewer gastrointestinal side effects than oral pamidronate. There is emerging evidence that bisphosphonates may delay or prevent the clinical appearance of bone metastases as well as reduce other skeletal complications. Trials of adjuvant bisphosphonates such as clodronate and pamidronate in operable breast cancer are currently under way in Europe and North America.