While on treatment, patients will be assessed as clinically indicated to discard progression with breast MRI. A biopsy will be performed to confirm progression and the patient will be removed from the study and treated according to investigator's criteria, usually with anthracycline-containing regimens (i.e. FE90C, 5FU 600 mg/m2 IV, epirubicin 90 mg/m2 IV, cyclophosphamide 600 mg/m2 IV, day 1 every 3 weeks).