Bisphosphonates: expanded roles in the treatment of patients with cancer.

Bisphosphonates are important inhibitors of osteoclastic bone resorption seen in patients with bone metastases associated with malignancy. Bisphosphonates are used in the treatment of patients with bone metastases and have been shown to reduce skeletal-related events and symptoms, contributing to improved patient outcomes and quality of life. These agents first were approved in the treatment of patients with osteoporosis and have been used for the past two decades in this role. Because bisphosphonates inhibit osteoclast-mediated bone resorption, the bone remodeling cycle slows down and an increase in bone mineral density occurs. These agents are useful in treatment for both hypercalcemia and pain, although they have not definitively shown improvement in survival time. Considerable interest exists in the use of bisphosphonates for prevention of bone metastases and their potential antitumor activity. These drugs are well tolerated and have minimal side effects, but they are not inexpensive. This article discusses the role of bisphosphonates in patients with cancer and future directions for further research.