Bone targeted
therapies are of increasing importance, not only for bone health in the
clinical course of
breast cancer, but recently also in the adjuvant setting as preventative, anticancer and prognosis-improving agents. It is well established that women with advanced
breast cancer receive
bisphosphonates or
denosumab to prevent
therapy-related
osteoporosis. As many as 70% of these patients suffer from bone
metastases and receive bone targeted agents in order to prevent skeletal related events (SREs), which are debilitating or diminish the quality of life. A number of trials provided guidance, identifying
zoledronic acid as the most efficient
bisphosphonate, showing that intravenous
bisphosphonate administration is superior to oral intake and illustrating the different safety profile of
denosumab, which has been reported to be more beneficial than
zoledronic acid in delaying the time to first and subsequent (multiple) SREs. New studies have suggested that bone targeted
therapies improve rates of overall survival and contribute to preventing recurrence of
breast cancer at all sites. Increased bone turnover is both a consequence and a driving factor for tumour growth, expansion, formation of bone lesions and potentially also activation of disseminated tumour cells, leading to bone relapses. We review the current knowledge of bone targeted
therapies in advanced
breast cancer, with a focus on new insights into their bone-preserving and antitumor activity. Current guidelines, pathology of bone
metastasis, mode of action and common side effects have been summarised. We also elaborate on the use of
bisphosphonates and
denosumab in early
breast cancer, during adjuvant
therapy with
aromatase inhibitors.