Long-term survival of HER2-positive breast cancer patients with brain metastases: subanalysis of the BMBC Registry

Background Up to 40% of patients (pts) with HER2-positive breast cancer (BC) develop brain metastases (BM). Identification of factors associated with long-term survival is important for the improvement of treatment modalities.

Methods A total of 1160 HER2-positive pts of the BMBC registry were available for this analysis. Long-term survival was defined as overall survival (OS) in the upper third of the survival curve resulting in a cut-off of 23 months. 328 pts were categorized as long-term survivors.

Results Long-term compared to short-term survivors were significantly younger at BC and BM diagnosis, had more often hormone receptor-positive tumor, better ECOG, lower BM number, lower rates of extracranial metastases and leptomeningeal metastases. Furthermore, long-term survivors were significantly more often treated with a combination of brain surgery and radiotherapy and were significantly more often neurologically asymptomatic.

Median OS in long-term survivors was 45.2 months. Following parameters were significantly associated with an assignment in the group of long-term survivors (multivariate logistic regression analysis): younger age (≥60 vs. <60 years OR=0.59, p=0.018), good performance status (ECOG 2-4 vs. 0-1 OR=0.51, p=0.006), lower number of BM (≥4 vs. 1 OR=0.53, p=0.015; 2-3 vs. 1 OR=0.66, p=0.127; overall p=0.046), absence of extracranial metastases (OR=0.58, p=0.028) and anti-HER2 targeted therapy (OR=1.98, p=0.005).

Conclusions We identified factors associated with long-term survival of HER2-positive BC pts with BM. Anti-HER2 targeted therapy after BM is an important factor associated with long-term survival.

Publication History

Article published online:
11 October 2022