Determination of Ca, Fe, Cu and Zn and their correlations in breast cancer and normal adjacent tissues

An experimental procedure using monoenergetic Synchrotron Radiation x-ray Fluorescence (SR-XRF) method was studied, justified and applied to determine trace elements concentrations of normal and neoplastic human breast tissues in the same individual. Scattered radiation from each sample was used as an internal standard in x-ray emission spectroscopy in order to construct calibration curves used to determine Ca, Fe, Cu and Zn concentrations in 52 breast tissue specimens (26 neoplastic and 26 adjacent normal tissues). This work showed that this experimental alternative is approximately matrix independent and also allows a reduction in instrumental variables. Our results showed, as expected, that Ca, Fe, Cu and Zn concentrations levels were significantly higher in neoplastic than in healthy breast tissues (all p < 0.001). It was also observed that Fe and Cu levels are correlated in malignant breast tissues as well as Ca and Zn levels, indicating that these elements' concentrations are related, in agreement with the hypothesis that there is a connection between Fe and Cu with both increased cellular activity and blood supply in the formation of neoplasies in breast tissue, and between Ca and Zn as regulators of neoplasies growth, since these metals are present in active matrix metalloproteinases (MMPs). Copyright (C) 2008 John Wiley & Sons, Ltd.