Brain metastases develop in 10 to 20% of patients with metastatic breast cancer, most often following disease progression at other sites. The one year patient survival is estimated at 20%. Brain metastases are treated with combinations of stereotactic radiosurgery, neurosurgery, whole brain radiation and steroids. However,this type of therapy may have serious consequences on quality of life of the patient, particularly with respect to cognitive function. Identification of the molecular alterations in these lesions, may help develop new therapies that may improve survival.