A Substantial Response from Adding Palbociclib to Endocrine Therapy in Brain Metastasis from Hormone Receptor-Positive, HER2-Negative Breast Cancer: Case Reports.

Brain metastasis (BM) from breast cancer has poor prognosis despite new advances and multi-modality treatments. No current data is guiding the use of palbociclib in the management of hormone receptor (HR)-positive breast cancer patients with BM as these patients were excluded systematically from all phase 3 trials. Here, we report an evident clinical response from combining palbociclib with endocrine therapy in HR-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer with BM.