(HealthDay News) – Postmenopausal women receiving the aromatase inhibitor exemestane to prevent breast cancer are more likely to have bone loss, according to a study published online Feb. 7 in The Lancet Oncology.
Angela M. Cheung, MD, from the University Health Network in Toronto, and colleagues analyzed bone mineral density (BMD) data from 351 postmenopausal women (median age, 61.3 years) who had been randomized to receive placebo or exemestane as part of a breast cancer prevention clinical trial.
After two years, the researchers found that, at the distal radius, total volumetric BMD and cortical thickness fell significantly more in women receiving exemestane compared with placebo (mean loss, 6.1% vs. 1.8% and 7.9% vs. 1.1%, respectively). Similar results were observed at the distal tibia (mean loss, 5% vs. 1.3% and 7.6% vs. 0.7%, respectively). Areal BMD also fell significantly more in the exemestane group at the lumbar spine, total hip, and femoral neck.
“Two years of treatment with exemestane worsens age-related bone loss in postmenopausal women despite calcium and vitamin D supplementation,” Cheung and colleagues conclude. “To assess the effect of our findings on fracture risk, long-term follow-up is needed.”