Upfront brain radiotherapy may improve survival for unfavorable prognostic breast cancer brain metastasis patients with Breast-GPA 0-2.0.

In this study, we attempted to assess the efficacy of upfront brain radiotherapy (RT) in breast cancer (BC) patients with brain metastases (BM). Medical records of 111 consecutive BC patients treated with WBRT or SRS between August 2009 and November 2017 in single center were retrospectively reviewed. Eighty patients received upfront brain RT after BM diagnosis and 31 had delayed RT. The median age at BM was 54 years (22-77), with median KPS 80 (50-90). The molecular BC subtypes of Luminal A, Luminal B, triple-negative and HER2 overexpression were 16, 47, 27, and 19, respectively, with 2 unknown. Of them, 83 received WBRT after BM and 28 SRS. Median overall survival (OS) was significantly related to Breast-GPA, as following: 6.5, 9.9, 14.4, and 24.5 months in 0-1.0, 1.5-2.0, 2.5-3.0, and 3.5-4.0 subgroups, respectively (P = 0.007). Univariate and multivariate analysis showed that KPS ≤70, infratentorial involvement, extracranial metastases, and no continuing systemic therapy were independent risk factors for OS. In the whole group, no significant difference in OS was found between upfront or delayed RT. For Breast-GPA 0-2.0 subgroup, upfront RT was associated with increased median OS (3.3 vs 9.8 months, P = 0.04). In GPA 2.5-4.0 subgroup, the median OS for upfront and delayed RT was 13.8 and 16.5 months, respectively (P = 0.58). In conclusion, BCBM patients with better KPS, systemic therapy, without infratentorial involvement and extracranial metastases are associated with better OS. Patients with Breast-GPA 0-2.0 might benefit from upfront brain RT.