Purpose: Aromatase inhibitors (AIs) represent the first-line adjuvant therapy for hormone receptor-positive breast cancer (BC) women. AIs have been associated with an increased rate of fractures. The aim of our study was to investigate trabecular bone score (TBS) and bone quantitative ultrasound (QUS) measurements as bone quality surrogates in AIs users.
Methods: Sixty postmenopausal BC women starting AIs and forty-two controls (mean age 61.64 ± 8.33 years) were considered. Bone mineral density (BMD) at lumbar spine and femoral neck and TBS were measured by DXA; QUS-derived Amplitude-Dependent Speed of Sound (AD-SoS), Bone Transmission Time (BTT), and Ultrasound Bone Profile Index (UBPI) were assessed at phalangeal site; morphometric vertebral fractures (Vfx) by X-ray, serum bone-specific alkaline phosphatase (BSAP), and C-telopeptide of type 1 collagen (CTX) were also evaluated.
Results: After 18 months, changes of TBS vs baseline were significantly different between AIs group and controls [Δ TBS - 2.2% vs - 0.4%, respectively, p = 0.001]. AD-SoS, BTT and UBPI values decreased only in AIs' group (- 3.7%, - 6.45%, -8.5%, vs baseline, respectively, pall < 0.001). 3 Vfx occurred in AIs users and were associated with the greater TBS and AD-SoS modifications. In the AIs' group, ΔTBS was associated with ΔAD-SoS (r = 0.58, p < 0.001) and ΔUBPI (r = 0.415, p = 0.001), but not with ΔBMD. Moreover, ΔTBS was independently predicted by ΔAD-SoS, after correcting for BMD, CTX and BSAP level changes (β = 0.37, SE = 2.44, p < 0.001).
Conclusions: TBS and phalangeal QUS provide useful information related to bone quality in AI-treated BC survivors and could be considered for fracture risk evaluation.
Keywords: Aromatase inhibitors; Bone quality; Breast cancer; Osteoporosis; Quantitative ultrasound; Trabecular bone score.