Breast cancer brain metastases: The graded prognostic assessment index (GPA) in a real-world low- and middle-income (LMIC) population.

Abstract

e18531 Background: Up to 15% of breast cancer patients develop brain metastases during the course of their disease. Graded Prognostic Assessment (GPA) estimates survival for patients with brain metastases. This retrospective analysis assesses the applicability of the GPA and highlights the outcomes for patients from a Low- and Middle-income Country (LMIC). We compared the GPA-predicted survival for each patient with the actual overall survival. Methods: A single-center retrospective analysis of patients identified from the neurosurgery, radiation therapy and palliative care databases of the Instituto Nacional de Câncer (INCA), Brazil, from October 2018 to June 2020. Survival analyzes were performed using the Kaplan-Meier method and the curves were compared by the Log-rank test. Results: We identified 110 patients with breast cancer brain metastasis and 84 patients were followed through December 2021. 10 patients were still alive at the end of follow-up. Median age at breast cancer diagnosis was 48 years, and median time from breast cancer diagnosis to brain metastases diagnosis was 30.6 months. 62% were premenopausal and ECOG-PS was 0 - 1 in 44%, and 2 in 25% of patients. 94% of tumors were of ductal histology, 43% hormone receptor (HR) +/HER2 - disease, 30% triple-negative, and 27% HER2 + (17% HR+ and 10% HR-). 22% stage IV disease at diagnosis. The median time from breast cancer diagnosis to brain metastases was 30.6 months (range, 0.3 to 232 months). 95% of patients were symptomatic at the time of the brain imaging, mainly headache and focal neurological deficit. 64% of patients had less than three brain metastases. Patients underwent neurosurgery (71%), stereotactic radiosurgery (13%) and WBRT (38%), and the median time from brain metastases diagnosis to local treatment was 18, 20 and 10 days, respectively. Median time from brain metastases to death was 5.5 months, being 4.0 months for HR+HER2-, 4.5 months for triple-negative, and 12.0 months for HER2+ disease (p = 0.18). The median time calculated according to the GPA for the whole patient population was 13 months. Conclusions: Breast cancer patients with brain metastases had a shorter median survival time than the one estimated by the GPA. We hypothesize that a delay between CNS symptoms and brain imaging may explain this worse outcome. The prognostic score is an important tool to assist in choosing therapeutic options. It can also highlight health disparities and consequently stimulate the search for potential strategies to improve patients outcomes.