Breast cancer is the most common type of cancer in females worldwide. Patients with breast cancer and bone metastases may experience increased osteoclast activity, resulting in local bone destruction and skeletal complications, including pain, hypercalcemia and skeletal-related events. Intravenous bisphosphonates (BPs) are the standard treatment administered to patients with breast cancer and bone metastases to prevent skeletal-related events. However, in certain patients, BPs may cause renal toxicity, acute-phase reactions and osteonecrosis of the jaw. More effective, safer and more tolerable therapies, which prevent bone destruction and skeletal complications, are required in order to improve patient quality of life. Denosumab is a fully human monoclonal antibody that binds to and neutralizes receptor activator of nuclear factor-κB ligand, which is a key mediator in the pathogenesis of a broad range of skeletal diseases, thereby inhibiting osteoclast function and bone resorption. Therefore, we conducted a meta-analysis to compare both the safety and efficacy of denosumab and BPs in the treatment of breast cancer and bone metastases. Five databases, two clinical trial registry platforms and reference lists of relevant papers were analyzed. The meta-analysis concluded that denosumab was more effective at preventing pain and skeletal-related events than BPs, in patients with breast cancer and bone metastases. Patients receiving denosumab demonstrated a higher level of clinical improvement in terms of health-related quality of life than patients receiving BPs. Compared with BPs, denosumab reduced the incidence of certain indicators of adverse events, including pyrexia, bone pain, edema and renal failure.
Keywords: bisphosphonates; bone metastases; breast cancer; denosumab; meta-analysis.