Prevention of aromatase inhibitor-induced bone loss with alendronate in postmenopausal women: the BATMAN trial

<b>Abstract:</b><br />Postmenopausal women on aromatase inhibitors (AI) are at risk of aromatase inhibitor-associated bone loss (AIBL) and fractures.<br /><br />In 2005 Osteoporosis Australia proposed an algorithm for bisphosphonate intervention. Three hundred and three postmenopausal women with early breast cancer (EBC) were enrolled (osteoporotic, n=25; osteopaenic, n=146; normal bone mineral density (BMD), n=126). Weekly alendronate (70 mg) treatment efficacy as triggered by the algorithm in preventing bone loss was evaluated. All patients received anastrozole (1 mg daily), calcium and vitamin D.<br /><br /><b><span style="font-size: 12px;">Results:</span></b><br /><span style="font-size: 12px;">All osteoporotic patients received alendronate at baseline. Eleven out of the 146 (7.5%) osteopaenic patients commenced alendronate within 18 months of participation and eleven commenced after. One hundred and twenty four out of the 146 (84.9%) osteopaenic patients and all 126 with normal baseline BMD did not trigger the algorithm.</span><br /><br />At three years, lumbar spine mean BMD increased (15.6%, p<0.01) in the osteoporotic group. BMD in the osteopaenic group with early intervention significantly increased at three years (6.3%, p=0.02). No significant change was seen in the late intervention group. No change was observed in those with osteopaenia without alendronate.<br /><br />There was a significant drop in lumbar spine (−5.4%) and hip (−4.5%) mean BMD, in the normal BMD group, none of whom received alendronate.<br /><br />Fracture data will be presented.<br /><br /><b>Conclusion:</b><br /><span style="font-size: 12px;">In postmenopausal women with endocrine-responsive EBC, BMD improved over time when a bisphosphonate is administered with anastrozole in osteoporotic patients using an osteoporosis schedule. Subjects with normal baseline BMD experienced the greatest BMD loss, although none became osteoporotic.</span>