Phalangeal quantitative ultrasound as assessment tool to evaluate bone loss in aromatase inhibitors related osteoporosis

Bone loss is a frequent occurrence in breast cancer (BC) women receiving aromatase inhibitors (AIs). Our aim was to assess bone mass by phalangeal quantitative ultrasound (QUS) and by DXA, and to evaluate bone turnover in women treated with AIs. 60 postmenopausal BC women and 42 matched control were recruited (mean age 61.64 ± 8.33 yr). QUS parameters (Ad-SoS, UBPI, BTT), L1-L4 and femoral neck BMD by DXA and vertebral fractures (Vfx) by X-ray were assessed at baseline and after 18 months; serum levels of bone-specific alkaline phosphatase (BSAP) and C-terminal telopeptide of procollagen type I (CTX), as bone formation and resorption markers respectively, were measured every 9 months. FRAX derived 10-years probability of major fractures and hip fractures were significantly associated to AD-SoS (r=-0.381, p<0.001 and r=-0.370, p<0.001, respectively), UBPI (r=-0.434, p<0.001 and r=-0.409, p<0.001, respectively), BTT (r=-0.309, p=0.002 and r=-0.340, p=0.001, respectively). The median percent changes of AD-SoS [-3.71 (-5.38 – 0.11) vs. -0.7 (-4.15 – 0.83), p=0.02 respectively] and BTT [-8.4 (-14.91 – -3.53) vs. -1 (-5.72 – 3.75), p<0.001 respectively] were significantly different between AI users and controls, and the same was observed for percent changes of lumbar spine BMD [-2.94 (-5.67 – -0.43) vs. -0.69 (-1.21 to 0.11), p=0.001 respectively], and femoral neck BMD [-2.5 (-6.39 –0.83) vs. -0.3942 (-1.49 – 1.29), p=0.01 respectively]. In AI users, increased bone turnover rate was observed, the percent changes of BSAP and CTX being significantly different in comparison with controls (p<0.01). AD-SoS modification was associated with change of BMD at lumbar spine (? 0.16, SE 0.08, p=0.04) and change of BSAP (? -0.04; SE 0.02; p=0.04). Phalangeal QUS appeared a reliable tool to evaluate bone quality also in BC women on AIs.