title: TBS and BMD at the end of AI-therapy: A prospective study of the B-ABLE cohort.
abstract: 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.
  
  
  
  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.
  
  
  
  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).
  
  
  
  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.
authors: IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain.
authors: Rodríguez-Sanz
authors: RS
authors: María
authors: IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain.
authors: Pineda-Moncusí
authors: PM
authors: Marta
authors: Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Servitja
authors: S
authors: Sonia
authors: IMIM (Hospital del Mar Research Institute), Red Temática de Investigación Cooperativa en Envejecimiento y Fragilidad (RETICEF), Barcelona, Spain. Electronic address: ngarcia@imim.es.
authors: Garcia-Giralt
authors: GG
authors: Natalia
authors: Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Martos
authors: M
authors: Tamara
authors: Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Tusquets
authors: T
authors: Ignasi
authors: Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Martínez-García
authors: MG
authors: Maria
authors: Internal Medicine Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Rodriguez-Morera
authors: RM
authors: Jaime
authors: 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.
authors: Diez-Perez
authors: DP
authors: Adolfo
authors: Cancer Research Program, IMIM (Hospital del Mar Research Institute), Medical Oncology Department, Hospital del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Albanell
authors: A
authors: Joan
authors: 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.
authors: Nogués
authors: N
authors: Xavier
mesh_terms: D015502:Absorptiometry, Photon / Q000639:trends; D000368:Aged; D047072:Aromatase Inhibitors / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy; D000071556:Cancellous Bone / Q000000981:diagnostic imaging* / Q000187:drug effects*; D015331:Cohort Studies; D004164:Diphosphonates / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects* / Q000502:physiology; D011446:Prospective Studies
chemical_list: D047072:Aromatase Inhibitors; D004164:Diphosphonates
keywords: Aromatase inhibitors; Bone mineral density; Breast cancer; Oral bisphosphonates; Tamoxifen; Trabecular Bone Score