This study is conducted to assess the effect of metformin addition to the chemotherapy protocol of non-diabetic breast cancer patients compared to the control group (non-metformin users) in the neoadjuvant setting. Evaluation of the the clinical benefit rate and the rate of pathological complete response will be conducted. In addition, a correlation between the beneficial effect of metformin and the serum concentration of metformin. Also, a comparison in the quality of life between the metformin group and the control group will be evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ C30) and (EORTC QLQ BR45) questionnaires will be done.
