Management of bone health in postmenopausal women on aromatase inhibitors (AIs): a single health care system experience

Aromatase inhibitors (AIs) are the preferred therapy for postmenopausal women with early-stage estrogen receptor-positive breast cancers. However, their use causes bone loss and increased risks of osteoporosis and fractures. This is a retrospective review of all postmenopausal women with breast cancer diagnosed and treated with AI between 2010 and 2015. Of the 564 women identified, 319 were eligible. The median age at AI initiation was 65 years (range 51-85 years), and the median duration of AI therapy was 28 months (1-72 months). The median number of DEXA scans per woman was 1 (0-4), performed at a median frequency of 24 months (1-48 months). Recommendations for calcium and vitamin D were in 66 and 59% of women, respectively. There were 52 (16%) women who received antiresorptive treatments with bisphosphonates (69%), denosumab (25%), or both drugs (6%). Based on guideline recommendations from six societies, starting antiresorptive treatment was unnecessary in 15-54% of women. In this single health system experience, women start antiresorptive drugs that are unnecessary in 15-52%. These results highlight the nonuniformity in guideline recommendations, and this has implications for quality of care, cost-effectiveness, and value-of-care analyses for preventing fractures.