by Jae Sik Kim, Kyubo Kim, Wonguen Jung, Kyung Hwan Shin,
Seock-Ah Im, Yong Bae Kim, Jee Suk Chang, Doo Ho Choi, Haeyoung Kim, Yeon Hee
Park, Dae Yong Kim, Tae Hyun Kim, Jeanny Kwon, Ki Mun Kang, Woong-Ki Chung,
Kyung Su Kim, In Ah Kim
The Breast: Open Access: Published: November 15, 2021
Background
To investigate outcomes of salvage whole-brain radiotherapy
(WBRT) for recurrent brain metastases (BM) from breast cancer (BC), to identify
prognostic factors of overall survival (OS), and to propose a novel prognostic
classification for OS in these patients.
Materials and methods
We identified 54 patients who had received salvage WBRT as
the second brain-focused treatment for recurrent BM from BC (2000–2014). The
median follow-up duration was 4.9 months. A recursive partitioning analysis
(RPA) was conducted to develop a model to predict OS at the time of salvage
WBRT.
Results
The median OS was 6.8 months. OS according to BC-specific
graded prognostic assessment (breast-GPA), modified breast-GPA, and updated
breast-GPA did not represent our cohort. In the multivariate analysis, a long
time before salvage WBRT (≥16 months), control of primary BC or extracranial
metastases, systemic treatment after salvage WBRT, and administration of a
biologically effective dose for an α/β of 10 Gy (BED10) of salvage WBRT
>37.5 Gy showed superior OS. We proposed three RPA classes based on the
control of both primary BC and extracranial metastasis and BED10 of salvage
WBRT: class I, class II, and class III. In this model, patients with class I
experienced the best OS (34.6 months; class II, 5.0 months; class III, 2.4
months; P < 0.001).
Conclusions
In our RPA classification according to the control of both
primary BC and extracranial metastasis and the dose of salvage WBRT,
significant differences in OS were observed. The subsequent use of a systemic
treatment showed better OS.
