Prevention and treatment of bone metastases.

Certain primary tumours including breast and prostate cancers have a particular propensity for metastasis to bone. Metastatic bone disease can have significant impact on morbidity and mortality of cancer patients. Skeletal-morbidity (spinal cord compression, hypercalcaemia, fracture, need for radiotherapy and surgery to bone) can be effectively reduced by bisphosphonates, a class of anti-resorptive drugs. They are also effective in relieving pain from bone metastases, and may improve survival in patients with accelerated bone resorption. Additionally, there is an exciting body of evidence that suggest these drugs may have anti-tumor effects that may be exploited to prevent or delay the development of bone metastases. Reported effects include inhibition of cancer cell migration, adhesion and invasion as well as anti-angiogenic and immunomodulating effects. The pre-clinical evidence is compelling, and some recently reported randomised clinical studies go part way to support their use in clinical practice at earlier stages of the disease to prevent bone metastases. However, further results are awaited before routine clinical use in the adjuvant setting can be recommended.