Pharmacotherapy Options in Cancer Treatment-Induced Bone Loss: Focus on Bisphosphonates

Bone loss and its associated risk of fracture is a serious long-term health issue for breast cancer and prostate cancer survivors. Hormone ablation therapy, in particular aromatase inhibitors (AIs) for breast cancer and androgen deprivation therapy (ADT) for prostate cancer, causes marked reduction in circulating estrogen or testosterone levels, resulting in increased bone resorption, decreased bone mineral density (BMD), and an increased risk of fragility fracture. In several clinical trials with small sample sizes and short follow-up periods, oral and intravenous bisphosphonates have been shown to improve BMD, but not actual fracture rates, in cancer patients on hormone ablation therapy. A number of professional organizations and expert panels recommend the use of bisphosphonates for selected patients at risk. Although bisphosphonates are generally well tolerated, physicians should be aware of safety concerns, including the risk of osteonecrosis of the jaw. With the growing number of older breast and prostate cancer survivors, additional research is needed to characterize patients who would benefit from pharmacotherapy and optimize strategies to prevent cancer treatment-induced bone loss.