Osteoporosis management in patients with breast cancer: EMAS position statement

Aromatase inhibitors (AIs) are the first-line recommended standard of care for postmenopausal estrogen receptor-positive breast cancer. Because they cause a profound suppression of estrogen levels, concerns regarding their potential to increase the risk of fracture were rapidly raised. There is currently a general consensus that a careful baseline evaluation is needed of the risk of fracture in postmenopausal women about to start treatment with AIs but also in all premenopausal women with early disease. Bisphosphonates have been shown in several phase III trials to prevent the bone loss induced by cancer treatment, although no fracture data are available. Even though they do not have regulatory approval for this indication, their use must be discussed with women at high risk of fracture. Accordingly, several guidelines recommend considering treatment in women with a T-score ≤-2 or those with two or more clinical risk factors. Moreover, recent data suggest that bisphosphonates, especially intravenous zoledronic acid, may have an anticancer effect, in that they reduce bone recurrence as well as extra-skeletal metastasis and breast cancer mortality in postmenopausal women. The anti-RANK ligand antibody denosumab is also emerging as a new adjuvant therapeutic option to prevent AI-induced bone loss. It has been shown to extend the time to first fracture in postmenopausal women treated with AIs. Several issues still need to be addressed regarding the use of these different agents in an adjuvant setting. The purpose of this position statement is to review the literature on antifracture therapy and to discuss the current guidelines for the management of osteoporosis in women with early breast cancer.