Characteristics of patients with brain metastases from HER2-positive breast cancer

Background About 40 % of patients with a metastatic HER2+ breast cancer (BC) develop brain metastases (BM). Understanding of clinical features of patients with HER2+ BC and BM is required.

Methods 2948 patients of the BMBC Registry were available for this analysis, 1311 of them had HER2+ subtype.

Results Patients with a HER2+ BC and BM were (compared to HER2- patients) slightly younger at time of BC and BM diagnosis, had a significantly higher pCR after neoadjuvant chemotherapy, higher tumor grading and had less common extracranial metastases (ECM) at time of BM diagnosis. HER2+ patients had significantly more often BM in the posterior fossa but less common leptomeningeal metastases (LM).The median overall survival (OS) in all HER2+ patients was 13.2 months (95 % CI 11.4-14.4). Following factors were significantly associated with a worse OS (multivariate analysis): older age (≥ 60 vs. < 60 years: HR 1.63, p< 0.001), lower ECOG (2-4 vs. 0-1: HR 1.58, p< 0.001), more BM (≥ 4 vs. 1:HR 1.51, p=0.003), BM in fossa anterior (HR 1.71, p< 0.001), LM (HR 1.63, p=0.012), symptomatic BM at diagnosis (HR 1.36, p=0.032), ECM at diagnosis of BM (HR 1.44, p=0.019) and the absence of targeted therapy (HR 0.616, p< 0.001).

ER2+/HR+ patients show significantly higher OS rates than HER2/HR- patients (median 14.3 vs. 10.9 months, p=0.027), but no differences in progression-free survival.

Conclusions The performed analysis identified factors associated with prognosis of HER2+ patients with BM. Further research is needed to understand the factors determining the longer survival of HER2+ HR-positive patients.

Publication History

Article published online:
01 June 2021