Evaluate the Effects of Breast Cancer Chemotherapy and Radiotherapy on Bone Matrix by Confocal Micro-beam X-ray Fluorescence

Breast cancer is one of the most common malignant tumors in women. Chemotherapy for breast cancer treatment can cause amenorrhea in women and significant bone loss. Consequently, post-menopausal women are at risk of morbidity and mortality associated with breast canner and postmenopausal osteoporosis. Here, a study on osteoporosis in rats after chemotherapy and/or radiotherapy was conducted based on confocal microbeam X-ray fluorescence (m-XRF) technique. Female sprague dawley (SD) rats were divided into 3 groups: control group (G1), chemotherapy and radiotherapy group (G2), and only radiotherapy group (G3). The SD rats were euthanized 6 months after chemotherapy and radiotherapy, and femur slices with a thickness of 1mm were taken for confocal μ-XRF analysis. It was found that compared with G1, G2 and G3 showed significant calcium loss, while Fe increased, especially in G2 group. The results indicate that the lack or reduction of estrogen caused by chemotherapy lead to the occurrence of osteoporosis, and the significant increase of bone iron in G2 samples suggests the process of osteoporosis. Iron ions compete with calcium ions, and there is a significant positive correlation between bone iron and bone absorption. Confocal μ-XRF has proven to be an effective analytical technique for evaluating the effects of chemotherapy and radiotherapy on osteoporosis.