IL6 and breast cancer: To investigate the relationship between changes in peripheral blood vascular endothelial growth factor (VEGF), interleukin-5 (IL-5), interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-17 (IL-17) concentrations in breast cancer patients and their significance and clinical value in breast cancer staging and invasive metastasis.