Docetaxel, Doxorubicin (A), Cyclophosphamide (C) (TAC) vs 5-Fluorouracil, A, C (5FAC) Breast Cancer Adjuvant Treatment

Primary objective: * To compare disease-free survival (DFS) after treatment with docetaxel in combination with doxorubicin and cyclophosphamide (TAC) to 5-Fluorouracil in combination with doxorubicin and cyclophosphamide (FAC) as adjuvant treatment of high risk operable breast cancer patients with negative axillary lymph nodes. Secondary objectives: * To compare overall survival (OS) between the 2 above mentioned arms. * To compare toxicity and quality of life between the 2 above mentioned arms. * To evaluate pathologic markers for predicting efficacy (hormonal receptors and human epidermal growth factor receptor 2 (HER2) protein expression).