Systematic review of the management of brain metastases from hormone receptor positive breast cancer

IntroductionBrain metastases are a common cause of morbidity and mortality in patients with breast cancer. Local central nervous system (CNS) directed therapies are usually the first line treatment for breast cancer brain metastases (BCBM), but those must be followed by systemic therapies to achieve long-term benefit. Systemic therapy for hormone receptor (HR+) breast cancer has evolved in the last 10 years, but their role when brain metastases occur is uncertain.MethodsWe performed a systematic review of the literature focused on management of HR+ BCBM by searching Medline/PubMed, EBSCO, and Cochrane databases. The PRISMA guidelines were used for systematic review.ResultsOut of 807 articles identified, 98 fulfilled the inclusion criteria in their relevance to the management of HR+ BCBM.ConclusionsSimilar to brain metastases from other neoplasms, local CNS directed therapies are the first line treatment for HR+ BCBM. Although the quality of evidence is low, after local therapies, our review supports the combination of targeted and endocrine therapies for both CNS and systemic management. Upon exhaustion of targeted/endocrine therapies, case series and retrospective reports suggest that certain chemotherapy agents are active against HR+ BCBM. Early phase clinical trials for HR+ BCBM are ongoing, but there is a need for prospective randomized trials to guide management and improve patients' outcome.