Hormone and HER2/neu receptor status is prognostic and predictive in breast cancer (BC) and guides the choice of therapy. Due to receptor conversion, receptor conversion may differ in metastases compared to primary tumor.
The aim of the present study is to analyze the prognostic value of receptor status, receptor conversion and clinical parameters in patients with operated BC brain metastases (BM).
Patients with breast cancer brain metastases (BCBM) treated in our institution between July 2007 and December 2019 were eligible for the study. Receptor status of BC, the corresponding BM, and the occurrence of receptor conversion was separately recorded for three common receptors: human epidermal growth factor receptor 2 (HER2/neu), estrogen receptor (ER), and progesterone receptor (PR). The association between the receptor status/receptor conversion and clinical parameters was adjusted for outcome-relevant patient and tumor characteristics.
The final analysis compromised 78 patients. HER2/neu receptor status in BM was associated with overall survival (p=0.033). Receptor conversion was identified in 39 (50.0%) individuals: HER2/neu n=9 (11.5%); ER n=22 (28.2%); PR n=25 (32.1%). In the final multivariate cox regression analysis, HER2/neu receptor conversion (adjusted hazard ratio (aHR)=3.58, p=0.006), Karnofsky Performance Status score <70% (aHR=3.11, p=0.048), infratentorial BM location (aHR=2.49, p=0.007) and age ≥55 at BM diagnosis (aHR=2.20, p=0.046) were independently associated with poorer survival.
Of three common BC receptors, only the HER2/neu receptor conversion was strongly associated with operated BCBM patients’ prognosis. Clinical relevance of re-evaluation of receptor status in BM favors surgical treatment of patients with non-eloquent BCBM.

Copyright © 2021. Published by Elsevier Inc.