REMS technology for Longitudinal monitoring of Denosumab therapeutic effect in breast cancer patients receiving Aromatase Inhibitors-based therapy

Background: Adjuvant endocrine therapy is the treatment for estrogen-receptor (ER)-positive breast cancer (BC). Aromatase inhibitors (AIs) significantly reduce recurrence risk but cause significant bone loss and increased fracture risk. Denosumab (DmAb), an anti-osteoporotic treatment, shows promise in mitigating these effects. Aims: To assess the short-term effects of DmAb and AIs on bone health in ER-positive BC patients using Radiofrequency Echographic Multi-Spectrometry (REMS) compared with DXA. Methods: Post-menopausal BC patients.receiving AIs who were referred for osteoporosis assessment were retrospectively identified and classified into two groups according to routine clinical management: patients receiving 60mg DmAb every 6 months (Group A) and not receiving any anti-osteoporotic treatment (Group B). Bone health was evaluated at baseline (T0), 6- (T1), 12- (T2), and 18-months (T3). DXA and REMS were performed at T0 and T2, while REMS alone was performed at T1 and T3. Results: Group B showed a decline in spine and femoral BMD at all time points by REMS and at T2 by DXA. Group A, receiving DmAb, exhibited significant BMD improvements at both sites, observed at all time points by REMS and at T2 by DXA. Conclusions: Routine bone monitoring during AI therapy is essential for primary osteoporosis prevention. This study, for the first time, quantifies the short-, medium- and long-term effects of AIs on bone loss and the positive impact of DmAb on bone density recovery in BC patients without the use of radiation. REMS proved to be a reliable tool for longitudinal monitoring of treatment response in patients receiving anti-osteoporosis therapy.