Changes in bone mineral density during 5 years of adjuvant exemestane therapy in postmenopausal women with early breast cancer.

e12003Background: Adjuvant therapy with aromatase inhibitors (AI) is associated with increased bone loss in postmenopausal women. The effect of 5 years of treatment with anastrozole on bone mineral density (BMD) was previously reported (Eastell R. J Clin Oncol 26:1051-1058, 2008). However, the effect of long-term (more than 2 years) therapy with exemestane (EXE) on BMD is still unknown. We assessed changes in BMD from baseline to 5 years of treatment in patients receiving EXE as initial adjuvant therapy with/without oral bisphosphonates (Bis). Methods: Postmenopausal women with endocrine-responsive breast cancer receiving EXE as adjuvant therapy at our hospital since 2005 were enrolled in this study. BMD was assessed by dual-energy X-ray absorptiometry at baseline and after 6, 12, 24, 36, 48, and 60 months. Oral Bis (risedronate or alendronate) treatment was initiated when patients were diagnosed with osteoporosis with a T-score of 2.5 or lower. Observation was censored when treatment of EXE was stopped b...