Retrospective cohort study of survival trends over time in patients with brain metastases from breast cancer

Approximately 20% to 30% of patients with metastatic breast cancer (mBC) devolop brain metastases (BrM). A retrospective cohort study at University of California San Francisco evaluated survival trends over time in mBC patients with BrM. The study included 507 patients with a diagnosis of BrM from mBC between 1997 and 2024. Median real-world overall survival (rwOS) from diagnosis of the first BM to death was 21.6 months, with the longes rwOS in patients with HER2+ disease (31.0 months), compared with 19.6 months in patients with HR+/HER2- disease and 12.8 months in patients with TNBC. By date of BrM diagnosis 1997-2014 versus 2015-2024 (approximately 50% of patients in each time period), patients with HER2+ and TNBC lived longer in the more modern cohort compared to prior years (HER2+ 41.2 versus 26.2 months; p=0.002; TNBC 14.9 versus 7.0 months; p=0.02); this was not the case in the HR+/HER2- group. The authors conlude that in this cohort th median rwOS was almost two years from the first BrM diagnosis. Favorable factors included HER2+ disease and diagnosis after 2014 (visual abstract).