Rodríguez-Sanz María1, Pineda-Moncusí Marta1, Servitja Sonia2, Garcia-Giralt Natalia3, Martos Tamara2, Tusquets Ignasi2, Martínez-García Maria2, Rodriguez-Morera Jaime4, Diez-Perez Adolfo5, Albanell Joan2, Nogués Xavier5. 1. IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain. 2. Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain. 3. IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain. Electronic address: ngarcia@imim.es. 4. Internal Medicine Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain. 5. IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain; Internal Medicine Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
Abstract
INTRODUCTION: Patients with breast cancer under aromatase inhibitor (AI) treatment often develop osteoporosis and their average bone loss rate is twice that of natural reduction during menopause, increasing fracture risk. As the current diagnostic technique based on bone mineral density (BMD) provides no information on bone quality, the Trabecular Bone Score (TBS) has been proposed to reflect bone microarchitecture status. The present study was designed to assess prospective changes in TBS and lumbar spine (LS) BMD in postmenopausal women with breast cancer at completion of AI treatment. METHODS: B-ABLE is a prospective cohort of 735 women with breast cancer treated with AIs according to American Society of Clinical Oncology recommendations: 5years of AI starting within 6weeks post-surgery or 1month after the last cycle of chemotherapy (5y-AI group), or switching to an AI to complete 5-year therapy after 2-3years of tamoxifen (pTMX-AI group). Patients with osteoporosis were treated with oral bisphosphonates (BP). TBS and LS-BMD changes at completion of AI therapy were evaluated by Student t-test for paired samples. Pearson correlation coefficients were computed for correlations between LS-BMD and TBS. RESULTS: AI treatment was completed by 277 women. Of these, 70 (25.3%) were allocated to BP therapy. The non-BP-treated patients (74.7%) showed significant decreases in TBS (-2.94% in pTMX-AI and -2.93% in 5y-AI groups) and in LS-BMD (-4.14% in pTMX-AI and -2.28% in 5y-AI groups) at the end of AI treatment. In BP-treated patients, TBS remained stable at the end of AI treatment, whereas LS-BMD showed significant increases (+2.30% in pTMX-AI and +5.33% in 5y-AI groups). Moderate associations between TBS and LS-BMD values at baseline and at the end of AI treatment (r=0.4; P<0.001) were observed. At the end of treatment, changes in spine BMD and TBS were weakly correlated (r=0.1, P<0.01). CONCLUSIONS: AI therapy induces significant decreases in TBS, comparable to BMD loss. BP-treated patients maintained TBS values, whereas BMD increased. AI treatment leads to deterioration of bone microarchitecture, which seems to be attenuated by BP therapy.
INTRODUCTION:Patients with breast cancer under aromatase inhibitor (AI) treatment often develop osteoporosis and their average bone loss rate is twice that of natural reduction during menopause, increasing fracture risk. As the current diagnostic technique based on bone mineral density (BMD) provides no information on bone quality, the Trabecular Bone Score (TBS) has been proposed to reflect bone microarchitecture status. The present study was designed to assess prospective changes in TBS and lumbar spine (LS) BMD in postmenopausal women with breast cancer at completion of AI treatment. METHODS: B-ABLE is a prospective cohort of 735 women with breast cancer treated with AIs according to American Society of Clinical Oncology recommendations: 5years of AI starting within 6weeks post-surgery or 1month after the last cycle of chemotherapy (5y-AI group), or switching to an AI to complete 5-year therapy after 2-3years of tamoxifen (pTMX-AI group). Patients with osteoporosis were treated with oral bisphosphonates (BP). TBS and LS-BMD changes at completion of AI therapy were evaluated by Student t-test for paired samples. Pearson correlation coefficients were computed for correlations between LS-BMD and TBS. RESULTS: AI treatment was completed by 277 women. Of these, 70 (25.3%) were allocated to BP therapy. The non-BP-treated patients (74.7%) showed significant decreases in TBS (-2.94% in pTMX-AI and -2.93% in 5y-AI groups) and in LS-BMD (-4.14% in pTMX-AI and -2.28% in 5y-AI groups) at the end of AI treatment. In BP-treated patients, TBS remained stable at the end of AI treatment, whereas LS-BMD showed significant increases (+2.30% in pTMX-AI and +5.33% in 5y-AI groups). Moderate associations between TBS and LS-BMD values at baseline and at the end of AI treatment (r=0.4; P<0.001) were observed. At the end of treatment, changes in spine BMD and TBS were weakly correlated (r=0.1, P<0.01). CONCLUSIONS: AI therapy induces significant decreases in TBS, comparable to BMD loss. BP-treated patients maintained TBS values, whereas BMD increased. AI treatment leads to deterioration of bone microarchitecture, which seems to be attenuated by BP therapy.