Metadata supporting the article: Outcomes of changing systemic therapy in patients with relapsed breast cancer and 1 to 3 brain metastases

The development of brain metastases (BMs) in breast cancer (BC) patients remains a challenging complication. Current clinical practice guidelines recommend local treatment of BMs without changing systemic therapy (CST) in patients with stable extracranial disease. In this study, the authors retrospectively investigated the impact of CST (when applicable as per treating physician’s discretion) following the diagnosis and management of oligometastatic (1-3) BMs in patients without extracranial metastases on the progression-free survival time (PFS), and overall survival (OS).

Data access: The data that support the findings of this study are not publicly available, but will be made available on reasonable request from the corresponding author, Dr. Nuhad K Ibrahim, email address: nibrahim@mdanderson.org.

Study approval and patient consent: The study was approved by the MD Anderson Cancer Center Institutional Review Board. Waiver of informed consent was granted by the IRB due to the retrospective nature of the study.

Study aims and methodology: Despite advances in systemic therapies and improved overall survival of metastatic breast cancer (MBC) patients, the development of brain metastases (BMs) remains a challenging complication in 10-20% of patients and affects quality of life and increases morbidity and mortality. In this study, the authors retrospectively investigated the impact of CST (when applicable as per treating physician’s discretion) after successful local management of the 1-3 BMs on the patient’s progression-free survival time (PFS) and on the patient’s overall survival (OS).

Among the 2645 patients with BC and BMs treated between 2002 and 2015, 74 were included for analysis. Patient information was collected from the electronic medical record database, including demographics, histological type, hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status, number of BMs, lack of extracranial disease at the time of BMs diagnosis, date of BMs diagnosis and subsequently confirmed disease progression in the brain or extracranially, the local therapy patients received after BMs diagnosis, the systemic therapy changes after BMs diagnosis and clinical outcomes. Patients with >3 BMs, or concurrent extracranial disease (n= 446), and duplicate or missing treatment data (n= 17) were excluded.

Statistical analysis, including calculations of overall survival and progression free survival, and Univariate Cox proportional hazards analyses, are described in more detail in the related article.

Data supporting figures, tables and supplementary tables: Dataset 1-3 Brain Mets breast cancer switch therapy n=74.xlsx, is in .xlsx file format. The dataset contains information including estrogen receptor (ER), progesterone receptor (PR) and HER2 receptor immunohistochemistry status, management (surgery, radiation or both), survival status, number and location of brain metastases.