Inclusion Criteria:

          -  Postmenopausal women presenting with histological proven (core biopsy material)
             hormone receptor positive (ER≥50%, PR any), HER2 negative, stage II/ III breast
             cancer.

          -  Measurable disease (breast and/or lymph nodes)

          -  WHO 0-2

          -  Adequate bone marrow function (within 4 weeks prior to registration): WBC≥3.0x109/l,
             neutrophils ≥1.5 x 109/l, platelets ≥100 x 109/l

          -  Adequate liver function (within 4 weeks prior to registration): bilirubin ≤1.5 x upper
             limit of normal (UNL) range, ALAT and/or ASAT ≤2.5 x UNL, Alkaline Phosphatase ≤5 x
             UNL

          -  Adequate renal function (within 4 weeks prior to registration): the calculated
             creatinine clearance should be ≥50 ml/min

          -  Accessible for treatment and follow-up

          -  Written informed consent

        Inclusion criteria randomization specific:

        In order to be eligible to be randomized in this study, a subject must meet all of the
        following criteria:

          -  Registration in the NEOLBC trial before 2 weeks biopsy

          -  Use of letrozole

          -  Outcome central Ki67 determination in two weeks biopsy available.

        Exclusion Criteria:

          -  Evidence of distant metastases (M1)

          -  Previous invasive breast cancer

          -  Prior chemotherapy, radiation therapy or hormonal therapy with the exception of
             patients who received letrozole ≤ 14 days (+ max. 4 days) prior to registration and
             who are still on letrozole.

          -  Previous malignancy within 5 years, with exception of a history of a previous basal
             cell carcinoma of the skin or pre-invasive carcinoma of the cervix.

          -  Peripheral neuropathy > grade 2, whatever the cause

          -  Serious other diseases as infections (hepatitis B, C and HIV), recent myocardial
             infarction, clinical signs of cardiac failure or clinically significant arrhythmias or
             on screening, any of the following cardiac parameters: bradycardia (heart rate <50 at
             rest) or QTcF ≥450 msec.

          -  Known hypersensitivity reaction to any of the components of the treatment (peanuts,
             soy)

          -  Currently receiving warfarin or other coumarin derived anti-coagulant, for treatment,
             prophylaxis or otherwise. Therapy with heparin, low molecular weight heparin (LMWH),
             or fondaparinux is allowed.

          -  Currently receiving any of the following substances and cannot be discontinued 7 days
             prior to randomisation:

               -  Known strong inducers or inhibitors of CYP3A4/5, including grapefruit, grapefruit
                  hybrids, pummelo's, star-fruit, pomegranate and Seville oranges.

               -  That have a known risk to prolong the QT interval or induce Torsades de Pointes.

               -  That have a narrow therapeutic window and are predominantly metabolized through
                  CYP3A4/5.

               -  Herbal preparations/medications, dietary supplements.

          -  Medical or psychological condition which in the opinion of the investigator would not
             permit the patient to complete the study or sign meaningful informed consent.