Utility of bisphosphonates in treating bone metastases.

Bone is the most common site of metastases from breast and prostate cancer, and bone destruction is characteristic of multiple myeloma. Increased osteoclast activity plays a key role in cancer-induced bone destruction. Bisphosphonates reduce osteoclastic bone resorption through various mechanisms as yet not fully elucidated. Bisphosphonates have proven to be effective in the treatment of tumor-induced hypercalcaemia. Several clinical trials indicated that these compounds can positively influence many aspects of neoplastic bone disease, however, many questions regarding their long-term efficacy and optimal therapeutic schedule await clarification from well-designed clinical trials.