Cortical and trabecular bone at the radius and tibia in postmenopausal breast cancer patients: A Peripheral Quantitative Computed Tomography (pQCT) study

Bone morbidity associated with antineoplastic treatment is a significant health concern for postmenopausal breast cancer patients. Trials have demonstrated that adjuvant therapy with an Aromatase Inhibitor is associated with an increase in musculoskeletal disorders and bone fractures. The objective of this study was to utilize Peripheral Quantitative Computed Tomography (pQCT) to assess in vivo trabecular and cortical volumetric bone at peripheral skeletal sites in healthy postmenopausal women and breast cancer patients prescribed Anastrozole. Fifty-eight women were recruited for this study: 27 breast cancer patients and 31 healthy control participants. pQCT measurements were taken at distal and diaphyseal sites of the radius and tibia using a Stratec XCT-2000 pQCT scanner. Bone measurement values for total density and total content at the 4% radius; total and cortical content as well as cortical density at the 20% radius; total density at the 4% tibia; and cortical density at the 38% tibia were found to be significantly lower in breast cancer patients. Moreover, the duration of time on Anastrozole showed a significant negative correlation with the following measurements: total content at the 4% radius (r=-0.36, p<0.01); total content (r=-0.33, p<0.05), cortical content (r=-0.34, p<0.05) and cortical density (r=-0.44, p<0.01) at the 20% radius; as well as cortical density (r=-0.39, p<0.01) and cortical content (r=-0.27, p<0.05) at the 38% tibia. Overall, the breast cancer patients demonstrated significantly lower values for volumetric bone density and content at the radius and tibia compared with healthy postmenopausal women. Furthermore, this novel study found adverse effects from Anastrozole treatment primarily in cortical bone.