The standard of care in bone
metastases is antiresorptive
therapy. If present in the bone,
tumor cells induce a vicious cycle by stimulating the osteoclasts, which further accelerates
tumor progression. The widely-used
bisphosphonates or the new therapeutic option,
denosumab an inhibitor of the receptor activator of NF-κB
ligand (RANKL), interrupt this vicious cycle, inhibit
tumor growth, and in clinical practice prevent skeleton-related events. Adjuvant oncological
therapy, including
chemotherapy and endocrine manipulations (ovarian ablation and
tamoxifen in premenopausal, and
aromatase inhibitors in postmenopausal women), increases the bone turnover and the risk of fracture. Awareness is essential for the diagnosis and treatment of
cancer therapy-induced bone loss, or its prevention with appropriate
calcium and
vitamin D supplementation. A new possibility has been suggested for the prevention of relapse: the use of
bisphosphonates in the adjuvant setting. Three large studies and their meta-analyses indicate that the inhibition of bone remodeling prevents the growth of dormant
tumor cells and
cancer relapse in the population of postmenopausal patients with a low-
estrogen environment in the skeleton. The similar potential of a RANKL inhibitor is currently under evaluation. Since the maintenance of bone integrity is necessary for the prevention of both
therapy-related side-effects and progression of the disease, the management of
breast cancer at any stage requires a careful consideration of the bone homeostasis.