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Background: Osteoporosis is a prevalent disease affecting 35% of spanish women over 50 years old [1]. It causes high morbidity and mortality mainly related to fractures.Breast cancer is equally a prevalent disease in Spain with an estimated incidence of 295,675 cases in 2023 according the ‘ Asociación Española contra el Cáncer ’ data [2]. Some treatments as aromatase inhibitors, gonadotropin-releasing hormone and some chemotherapic agents are considered osteoporosis risk factors [3]. Computed tomography (CT) measured volumetric bone mineral density (BMD) has been related to osteoporotic fractures [4]. In light of this, we propose performing a screening for osteoporosis using CT scan in the context of cancer staging in patients with breast cancer. This would save patients time and diagnostic tests exposure as well as reduce health spending.
Objectives: Primary objective: to determine the correlation between CT and densitometry (DXA) measured BMD. Secondary objective: to establish the relationship between CT measured BMD and osteoporotic fractures in breast cancer patients.
Methods: A retrospective cross-sectional study was conducted. We included postmenupausal women diagnosed with breast cancer and monitored at the Oncology Department of our hospital. Data were collected on demographic and clinical characteristics, and imaging findings. BMD was measured by DXA at L1, total lumbar spine, total hip and femoral neck, and was expressed as the absolute value and standard deviation (SD) of the mean for the young adult population of the same sex and geographical area (T-score). A ROI (Region Of Interest) was placed at L1 vertebra and HU (Hounsfield Units) were measured at CT. All patients underwent contrast enhanced CT scan. Patients with L1 fracture were excluded in order not to interfere with BMD measure. For patients with L2-L4 vertebral fractures, we examined DXA results excluding the fractured vertebrae. We considered vertebral morphometric and/or clinical fractures, and proximal humerus and hip fractures. Percentage was calculated for categorical variables and mean and SD or median and interquartile range (IQR) for continuous variables, depending on the distribution of the data. Comparison of means was carried out with the Student’s t tests when data were normally distributed, and otherwise with Kruskal–Wallis/Mann–Whitney U tests. Pearson vs Spearman correaltion was used for correlations between scale variables, depending on data distribution. P values < 0.05 were considered significant.
Results: We included 106 patients with a mean age of 66.760 years (± SD 9.281). The rate of osteoporotic fracture was 8.5%: 8 patients suffered vertebral fractures and 1 suffered a proximal humerus fracture. A weak correlation was found between BMD measured by CT at L1 and BMD measured by DXA at L1 (r= 0.277, p= 0.005), total lumbar spine (r= 0.230, p= 0.020), and femoral neck (r= 0.209, p= 0.036). L1 bone density measured by CT and total hip bone density measured by DXA was lower in fractured patients with stronger differences for total hip DXA.
Conclusion: Opportunistic bone density measure by CT in the context of breast cancer staging could be an efficient method for detecting patients at risk of osteoporotic fracture.
REFERENCES: [1] Naves M, Díaz-López JB, Gómez C, Rodriguez-Rebollar A, Cannata-Andia JB. Determinants of incidence of osteoporotic fractures in the female Spanish population older than 50. Osteoporos Int. 2005;16:2013-17.
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[3] Shapiro CL. Osteoporosis: A Long-Term and Late-Effect of Breast Cancer Treatments. Cancers (Basel). 2020 Oct 23;12(11):3094.
[4] Löffler MT, Jacob A, Valentinitsch A, Rienmüller A, et al. Improved prediction of incident vertebral fractures using opportunistic QCT compared to DXA. Eur Radiol. 2019 Sep;29(9):4980-4989.
Acknowledgements: NIL.
Disclosure of Interests: None declared.
© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (