Evaluation of radiotherapy and chemotherapy effects in bone matrix using X-ray microfluorescence

Premenopausal women undergoing adjuvant chemotherapy and/or radiotherapy for Breast Cancer (BC) treatment have significant bone loss. This high bone mineral density loss can lead to an increased risk of fractures. In this study, there were evaluated parameters involved in osteoporosis when rats were subjected to a chemotherapy regimen (TC) and/or irradiation (IR). Female Wistar rats were divided into 3 groups: control (G1), TC+IR (G2) and IR (G3). The animals were euthanized after 5 months at the end of treatment and their femurs were excised and dissected. Sections of 10 mu m thick were used for mu XRF analysis at the National Laboratory of Synchrotron Light. The uteri of these rats were collected and weighed. The obtained results showed that animals from G2 had a significant reduction (p <0.05) of uterine mass when compared to control. The qualitative analysis performed by pXRF showed that animals from G2 had iron in bone composition of the femurs. This same result was notobserved in animals from G1 and G3 groups. These results suggest that early menopause occurs and osteoporosis begins, probably because of the absence, or reduced, production of estrogen. The presence of iron in the G2 samples in indicates the process of osteoporosis, because according to literature, this ion is competitive with calcium ions. (C) 2013 Elsevier Ltd. All rights reserved.