AB0823 TRABECULAR BONE SCORE AT LUMBAR SPINE IS ASSOCIATED WITH QUANTITATIVE ULTRASOUND MEASUREMENTS AT PHALANGEAL SITE IN BREAST CANCER SURVIVORS RECEIVING AROMATASE INHIBITORS

Background: In breast cancer (BC) survivors, the age-related reduction in bone mineral density is exacerbated by aromatase inhibitors (AIs) treatment. AIs disrupt also bone quality and enhance fracture risk in aging women. Consequently, bone health evaluation is mandatory in BC women receiving AIs. Objectives: Quantitative ultrasound of bone (QUS) and trabecular bone score (TBS) are recognized tools to explore bone health beyond bone mineral density (BMD). The aim of our research was to explore the association of TBS with QUS measurements at phalangeal site in a setting of postmenopausal women taking aromatase inhibitors (AIs). Methods: BMD at lumbar spine, femoral neck and TBS were evaluated by a DXA densitometer (Hologic Discovery). Amplitude Dependent Speed of Sound (AD-SoS), Bone Transmission Time (BTT) and Ultrasound Bone Profile Index (UBPI) were detected at phalangeal site by Bone Profiler (Igea). Results: In 102 postmenopausal women (mean age 61.64 ± 8.33 yr.) (60 AIs treated and 42 controls), at baseline examination, TBS was negatively associated with age (r=-0.39, p<0.001) and positively related with T-score values at lumbar spine and femoral neck. After 18 months, ADSoS, UBPI and BTT values were significantly decreased in BC women receiving AIs (-3.7%, -6.45%, -8.5%, respectively, p<0.001 for all), but not in controls (-0.7%, -3.53%, -2.97%, respectively). Change of BMD at lumbar spine was significantly different between AIs treated women and controls (-2.94% vs. -0.69%, p=0.001) and the same result was observed as for BMD at femoral neck (-2.5% vs. -0.39%, p=0.01). Percent change of TBS was significantly greater in AIs treated women in comparison with controls (-2.2% vs. -0.4%, respectively, p=0.02). In AIs treated women, but not in controls, CTX levels significantly increased after 18 months [0.47 (0.36 to 0.62) vs. 0.66 (0.43 to 0.77), p=0.0004] and the same trend was observed as for BSAP levels [14 (13.01 to 15.57) vs. 15 (13.75 to 16.75), p=0.003]. At a multiple regression analysis, change of TBS was independently predicted by change of AD-SoS, after correcting for BMD change at lumbar spine and femoral neck and for modification of CTX and BSAP levels (b= 0.37, SE= 2.44, p<0.001). Conclusion: TBS variation was independently predicted by phalangeal QUS measurement in AIs treated BC women. Phalangeal QUS may represent an alternative tool to evaluate bone health also in this setting of patients. REFERENCES [1] Catalano A, Morabito N, Agostino RM, Basile G, Gaudio A, Atteritano M, Natale G, Xourafa A, Morini E, Adamo V, Lasco A. Bone health assessment by quantitative ultrasound and dual-energy x-ray absorptiometry in postmenopausal women withbreast cancer receiving aromatase inhibitors. Menopause. 2017 Jan;24(1):85-91. [2] Catalano A, Morabito N, Basile G, Fusco S, Castagna G, Reitano F, Albanese RC, Lasco A. Fracture risk assessment in postmenopausal women referred to an Italian center for osteoporosis: a single day experience in Messina. Clin Cases MinerBone Metab. 2013 Sep;10(3):191-4. [3] Martineau P, Leslie WD. Trabecular bone score (TBS): Method and applications. Bone. 2017 Nov;104:66-72.