Primary objective of the study in patients without a sufficient sonographic response (i.e. iNC) to 2 cycles of TAC as preoperative treatment of operable (T>/= 2cm, N0-2,M0) primary breast cancer: To determine the response rate determined by sonography (iRR = iCR+iPR) of further 4 cycles of docetaxel, doxorubicin and cyclophosphamide (TAC) and of 4 cycles of vinorelbine and capecitabine (NX) (TAC vs. NX)