Increased fracture rate in women with breast cancer: a review of the hidden risk

Fracture risk during treatment for breast cancer may be influenced by the rate of BMD loss and the consequent rapid alterations in bone microarchitecture, in addition to the established fracture risk factors in postmenopausal osteoporosis. The rapid decrease in BMD during adjuvant chemoendocrine therapy for breast cancer may necessitate more aggressive pharmacotherapy than is indicated for healthy postmenopausal women who develop osteoporosis. Over the last few years, clinical trials have established the effectiveness of bisphosphonates and other antiresorptive agents to preserve BMD during adjuvant therapy for early breast cancer. In addition, some bisphosphonates (eg, zoledronic acid) may also delay disease recurrence in women with hormone-responsive tumors, thereby providing an adjuvant benefit in addition to preserving BMD and potentially preventing fractures.It is likely that a combined fracture risk assessment (eg, as in the WHO FRAX algorithm) will more accurately identify both women with postmenopausal osteoporosis and women with breast cancer who require bone-protective therapy.Women with breast cancer (BC), even in the absence of skeletal metastases, are known to have a higher incidence of fractures than women of the same age without BC. A case control study performed before aromatase inhibitors (AIs) were part of standard medical practice showed that at the time of diagnosis, women with BC did not have a higher prevalence of vertebral fracture than controls. However, when followed after diagnosis, women with nonmetastatic BC had a higher rate of fractures compared with age- and weight-matched controls [1]. Fracture incidence was even higher (HR = 22.7; 95% CI = 9.1, 57.1; P < .0001) in women with recurrent disease but without skeletal metastases (Table 1) [1]. The increase in fracture incidence was maintained in analyses excluding women who eventually developed skeletal metastases (HR = 2.8; 95% CI = 1.3, 6.2). These data are rendered even more compelling