Management of cancer treatment-induced bone loss

The survival prospects for many patients with cancer are steadily improving. As a result, survivorship issues are of increasing importance as attempts are made to minimize the long-term adverse effects of cancer treatments. Cancer therapies can adversely affect bone health, particularly in women with breast cancer and men with prostate cancer. Strategies for screening patients at increased risk for fragility fracture, and treatment algorithms using both bone-targeted treatments and other therapeutic interventions, are being developed. Both bisphosphonates and denosumab have been evaluated as treatments to prevent or reverse the bone loss associated with cancer treatments. Zoledronic acid is the most extensively assessed agent and has been shown to prevent bone loss in patients with breast cancer experiencing a premature menopause, in postmenopausal women receiving an aromatase inhibitor and in patients with prostate cancer undergoing androgen deprivation therapy (ADT). To date, the improvements in bone mineral density have not translated into a reduced fracture rate. However, in a large phase III trial, denosumab has been shown to reduce vertebral fractures in men receiving ADT for prostate cancer. These bone-targeted treatments have also been shown to modify the course of the underlying cancer and prevent metastasis, although the beneficial effects are confined to patients with low levels of circulating reproductive hormones.