Managing aromatase inhibitor-associated bone loss in breast cancer

Although the incidence of breast cancer has increased, there is a concurrent decrease in the death rate, and the outlook for women with early-stage breast cancer remains positive. The current 5-year survival rate of women diagnosed with breast cancer is nearly 90%, due, in part, to the use of effective adjuvant therapies that often include aromatase inhibitors. However, long-term treatment with these therapies is known to have adverse effects on bone metabolism, leading to bone loss. Bone loss during adjuvant endocrine therapy may be higher than that observed during menopause and may require more potent therapy. Although there are approved treatments for osteolytic bone lesions from bone metastases, there is no approved therapy for bone loss associated with adjuvant cancer therapy. Bisphosphonates have demonstrated promising results in this setting, and zoledronic acid is currently under consideration by the US FDA and Europe (EMEA) for the treatment of aromatase inhibitor-associated bone loss.