[Encounter of cancer cells with bone. Treatment of bone metastases from breast cancer].

In metastatic breast cancer the most common metastatic site is bone. Skeletal-related events (SREs) as well as bone pain are well-known characteristics of bone metastasis. Activation of osteoclast is the most important mechanism for the progression of bone metastasis. To treat bone metastasis, not only administration of antitumor drug but also inhibition of osteoclast activity should be required. Bisphosphonates, as potent inhibitors of osteoclast function, reduce the morbidity of metastatic bone disease, decrease the prevalence of SREs, and improve control of bone pain. Molecular targeted agents which inhibit maturity and activity of osteoclast are under development, and some effectiveness has been proved in clinical trials. Long-term survival just like good control of a symptom is expected in future by using new drugs specific to bone metastasis as part of multidisciplinary approach.