title: Challenges in the treatment of hormone receptor-positive, HER2-negative metastatic breast cancer with brain metastases.
abstract: Brain metastases are a major cause of morbidity and mortality for women with hormone receptor (HR)-positive breast cancer, yet little is known about the optimal treatment of brain disease in this group of patients. Although these patients are at lower risk for brain metastases relative to those with HER2-positive and triple-negative disease, they comprise the majority of women diagnosed with breast cancer. Surgery and radiation continue to have a role in the treatment of brain metastases, but there is a dearth of effective systemic therapies due to the poor penetrability of many systemic drugs across the blood-brain barrier (BBB). Additionally, patients with brain metastases have long been excluded from clinical trials, and few studies have been conducted to evaluate the safety and effectiveness of systemic therapies specifically for the treatment of HER2-negative breast cancer brain metastases. New approaches are on the horizon, such as nanoparticle-based cytotoxic drugs that have the potential to cross the BBB and provide clinically meaningful benefits to patients with this life-threatening consequence of HR-positive breast cancer.
authors.affiliation: Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA. liu.minetta@mayo.edu.
authors.forename: Minetta C
authors.initials: MC
authors.lastname: Liu
authors.affiliation: Ramon y Cajal University Hospital, Madrid, Spain.|Vall D'Hebron Institute of Oncology, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Cortés
authors.affiliation: Baylor-Sammons Cancer Center, Texas Oncology, U.S. Oncology, Dallas, TX, USA.
authors.forename: Joyce
authors.initials: J
authors.lastname: O'Shaughnessy
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000556:secondary / Q000628:therapy*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D002986:Clinical Trials as Topic; D003131:Combined Modality Therapy; D019468:Disease Management; D055808:Drug Discovery; D005260:Female; D006801:Humans; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D018570:Risk Assessment; D059039:Standard of Care; D016896:Treatment Outcome
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: Blood-brain barrier; Blood-tumor barrier; Brain metastases; Breast cancer; Hormone receptor-positive breast cancer