Enhancing Quality of Life for Breast Cancer Patients with Bone Metastases

Abstract : The skeleton is the most common site of metastasis for women with advanced stage breast cancer (5, 8, 22). Severe osteolysis that is often associated with this stage of the disease can lead to skeletal related events such as pathological fracture severe bone pain and hypocalcaemia. The current standard of care for treating osteolytic bone metastases includes palliating bone pain through radiation therapy and blocking ongoing osteoclastic bone resorption with a bisphosphonate. Results from clinical trials indicate that anywhere from 6 to 26% of metastatic bone lesions treated with radiation therapy will go on to develop pathological fractures (11 23). Recent clinical data has shown that zoledronic acid a third generation bisphosphonate decreased the number of skeletal related events by 39% compared to placebo (1 2). Clinicians recognize that prevention of skeletal complications considerably improves the quality of life for these patients (4); and although bisphosphonates can decrease the chances of a patient developing a skeletal complication many are still at risk. In an effort to address this issue we hypothesized that the combination of an anabolic agent parathyroid hormone (PTH 1-34) in conjunction with a bisphosphonate (zoledronic acid ZA) and radiation therapy (RTX) for the treatment of metastatic bone lesion from breast cancer would stimulate new bone fdrmation improve mechanical properties and thus decrease the risk of subsequent pathological fractures.