OBJECTIVES: Community health systems (CHS) in the US play a large role in the care of patients with cancer, with over 50% of patients with cancer cared for in CHS. The systemic treatments used among patients with advanced HER2- breast cancer seen in these CHS are not widely published. This analysis describes the systemic treatment utilization across a sample of CHS.

METHODS: A retrospective analysis was performed utilizing the Syapse Learning Health Network^TM (LHN), an electronic medical record (EMR) derived database that collects cancer care data from multiple settings within CHS across 33 states, 450+ hospitals and from patients cared for by 1,900+ oncologists. Patients >18 yo, diagnosed with advanced breast cancer stages (IIIB+) from January 1, 2017 through December 10, 2021, were identified from the Syapse LHN using ICD-10 codes. Data utilized for this analysis included both structured data (set EMR fields like sex and birth date) and unstructured data (e.g. physician notes) validated by Syapse’s Certified Tumor Registrars and then descriptively summarized.

RESULTS: 2,875 patients from the LHN with advanced HER2- breast cancer (stage IIIB+) were included in the analysis. 2,019 patients (70%) received antineoplastic systemic treatment; in the 1L setting 59% received chemotherapy, 43% received hormone therapy and 21% received targeted therapy. Agents included: cyclophosphamide,37%; doxorubicin, 34%; paciltaxel, 24%; letrozole, 21%; palbociclib, 14%; anastrozole,13%; carboplatin, 8%; and docetaxel, 7%.

CONCLUSIONS: Consistent with management guidelines, HER2- patients with advanced breast cancer treated within CHS were most likely to receive chemotherapy in the 1L setting. Further analysis is necessary to better understand management decisions for this group of patients cared for within CHS.