Bisphosphonates in Breast Cancer Patients with Bone Metastases

Morbidity and mortality in breast cancer patients are mainly caused by organ failure as a result of distant metastasis. The main target of metastatic disease is the skeleton (next to lungs and liver). Osseous metastases are diagnosed in 75-80% of all women who die due to breast cancer; and the skeleton is the primary metastatic target organ in more than half of these cases. In Germany, the incidence of breast cancer patients with newly diagnosed bone metastases is approximately 11-12,000 cases. Prevalence might amount to 40,000 cases of women with breast cancer and osseous metastases at a median survival time of 3-4 years. The treatment goal at this stage of the disease comprises improvement of quality of life, and reduction of bone pain and typical complications like fractures and hypercalcemia. By consistent use of bisphosphonates these goals can be accomplished. Bisphosphonates improve bone pain significantly and reduce the number of skeletal-related events in women with bone metastases. Bisphosphonates can be administered intravenously or orally, and are well tolerated. Nevertheless, there are side effects and complications including acute phase reaction, nephrotoxicity, osteonecrosis of the jaw, and gastrointestinal disturbances.