Effects of exemestane and tamoxifen on bone health within the Tamoxifen Exemestane Adjuvant Multicentre (TEAM) trial: results of a German, 12-month, prospective, randomised substudy.

BACKGROUND Adjuvant treatment of hormone receptor-positive breast cancer in postmenopausal women with aromatase inhibitors may be associated with increased bone loss. PATIENTS AND METHODS Two hundred patients were randomised to receive exemestane or tamoxifen as adjuvant treatment of hormone receptor-positive breast cancer. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry at baseline and after 6 and 12 months treatment. RESULTS One hundred and sixty-one patients were assessable. Tamoxifen treatment resulted in a 0.5% increase from baseline in BMD at the spine, which was maintained at 12 months. Exemestane-treated patients experienced a 2.6% decrease from baseline in BMD at the spine at 6 months and a further 0.2% decrease at 12 months. There were significant differences in the changes in BMD between tamoxifen and exemestane at 6 and 12 months (P = 0.0026 and P = 0.0008, respectively). The mean changes in BMD from baseline at the total hip were also significantly different between exemestane and tamoxifen at 6 and 12 months (P = 0.0009 and P = 0.04, respectively). There was no difference between tamoxifen and exemestane in mean changes in BMD from baseline at the femoral neck. CONCLUSIONS Exemestane treatment resulted in an increase in bone loss at 6 months; bone loss stabilised after 6- to 12-month treatment.