The treatment of locally advanced breast cancer is a complicated issue. For neoadjuvant treatment is often needed to downstage locally advanced BC tumors prior to surgery, however many patients do not achieved objective response during treatment. The ability of melatonin and metformin to decrease side effects of chemotherapy had been investigated, moreover several studies confirm, that this drugs in combination with conventional treatment may increase objective response. But, this data is still controversial. We hypothesized that combinations of melatonin and conventional chemotherapy regimen such as FDC could be more effective than FDC alone in terms of response rate.