Neoadjuvant Response-guided Treatment of Luminal B-type Tumors and Luminal A-type Tumors With Node Metastases

The purpose of this neoadjuvant trial is to evaluate efficacy and toxicity of chemotherapy using weekly paclitaxel (arm A) versus the combination of the cdk 4/6 inhibitor palbociclib and standard endocrine treatment (arm B). After 12 weeks treatment is switched crossover. During the 24-weekly treatment period, clinical and radiological evaluations are performed repeatedly. Switch between the treatment arms A and B is allowed in case of lack of response or due to toxicity. A translational subprotocol is a mandatory part of the study protocol, except for use of PET-CT evaluations. Postoperatively, patients receive three 3-weekly courses of chemotherapy with a combination of epirubicin and cyclophosphamide.