Women and Bone Health: Maximizing the Benefits of Aromatase Inhibitor Therapy

Postmenopausal women with early breast cancer (EBC) are already at risk for bone loss, osteoporosis and fracture as they age because of declining estrogen levels. Adjuvant hormonal therapy with aromatase inhibitors (AIs; e.g. letrozole, anastrozole, exemestane) can exacerbate this risk. All three AIs appear to have similar effects on bone, increasing bone turnover and fracture risk in postmenopausal women with EBC. Risk factors for bone loss can be used to assess fracture risk and the need for ongoing assessment and/or treatment in postmenopausal women receiving AIs for EBC. The concomitant, up-front use of intravenous bisphosphonate therapy, such as zoledronic acid, in combination with AIs can inhibit bone loss. In addition, a strong body of evidence suggests an anticancer activity of bisphosphonate therapy with zoledronic acid in EBC in both the pre- and postmenopausal adjuvant setting. Zoledronic acid thus provides a therapeutic option for postmenopausal women with EBC who may be at higher risk for bone loss while on AIs, allowing more patients to receive treatment with effective adjuvant hormonal therapy to prevent recurrence.