The evolving role of bisphosphonates.

Bisphosphonates, analogs of pyrophosphate, bind to bone at sites of active bone remodeling. In clinical settings of rapid bone turnover and/or excessive osteolytic activity, they have been shown to have beneficial clinical effects. These settings include Paget's disease of bone, osteoporosis from a variety of clinical causes, and malignant bone disease. Bisphosphonate inhibition of osteolysis in cancer has been shown to be effective therapy for malignancy-associated hypercalcemia and as adjunctive therapy for the delay or prevention of cancer-related skeletal morbidity, including bone pain, pathologic fractures, and need for radiation therapy. Animal models of bone metastasis prevention by bisphosphonate treatment have provided the preclinical background for the adjuvant use of bisphosphonates in primary cancers. The success of these clinical trials has provided strong impetus for new research on bone disease and malignancy, as well as the development and testing of new and more potent bisphosphonates. Semin Oncol 28:284-290.