The effect of exemestane and tamoxifen on bone health within the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial: a meta-analysis of the US, German, Netherlands, and Belgium sub-studies

We performed a meta-analysis of three sub-studies of the randomized Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial to determine the effects of exemestane and tamoxifen on bone health. Patients received exemestane or tamoxifen as adjuvant therapy for hormone receptor-positive breast cancer. Bone mineral density (BMD) was assessed at baseline and after 12 and 24 months of treatment. Bone turnover markers were also measured. Patients receiving tamoxifen showed a mean increase from baseline in lumbar spine BMD of 1.2% at month 12 and 0.2% at month 24. Patients receiving exemestane showed a mean decrease from baseline of 2.6% after 12 months and 3.5% after 24 months. There were significant differences in the changes in lumbar spine BMD between treatment groups (P < 0.0001 at both time points). Changes in BMD from baseline at the total hip were also significantly different between exemestane and tamoxifen (P < 0.05 at both time points). Bone turnover markers decreased from baseline with tamoxifen and increased with exemestane. Exemestane resulted in decreases in BMD and increases in bone turnover markers. BMD increased and bone turnover markers decreased with tamoxifen.