The Effect of Zinc- and Copper Sulphate Supplementation on Tumor and Hair Concentrations of Trace Elements (Zn, Cu, Fe, Ca, Mg, P) in Rats with DMBA-Induced Breast Cancer

The aim of our study was to evaluate the mineral composition (Zn, Cu, Ca, Fe, Mg, P) of breast tumor tissue and hair, and to investigate the role of Zn and Cu contents in diet on tumor development, with DMBA-induced rat breast cancer being the experimental model. Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet, were treated with Zinc ions (Zn) or Copper ions (Cu) via gavage for a period of from 40 days to 20 weeks of age. Regardless of diet (standard feed; Zn; Cu), DMBA-induced breast carcinogenesis was not inhibited. On the contrary, in the Cu-supplemented group, tumorigenesis developed at a considerably faster rate. Regardless of diet (standard feed; Zn; Cu), the induced tumors showed increased Fe and decreased Mg levels in contrast to those in the normal control tissue. Additional supplementation of the rat diet with Zn and Cu also resulted in an increased Cu level, with no effect on the Zn concentration. Most study groups (standard; Zn) also had an increased Fe content and decreased Mg, Ca, and P levels in the rat hair as compared with those in the controls.