The patient has a past medical history significant for right-sided estrogen receptor (ER)-positive and left-sided ER-negative breast cancers in 2005 and 2009, respectively, and recent 1-year history of ER-positive right-sided breast cancer with bone and brain metastases.
Breast cancer brain metastases (BM) affect younger women disproportionally, including those lacking estrogen receptor (ER), progesterone receptor, and HER2 (known as triple-negative breast cancer; TNBC).
Therefore, we aimed to systematically investigate the impact of ET after diagnosis of BM on outcome and clinical course of disease in patients with ER-positive MBC.
25 patients out of 129 with a complete receptor information from both primary tumor and BM (ER, PR, HER2) available, had a change in receptor status: 7 of 26 (27%) ER/PR-positive/HER2-negative primaries (3 gained HER2; 4 lost expression of ER/PR); 10 of 31 (32%) ER/PR-positive/HER2-positive primaries (4 lost ER/PR only; 3 lost HER2 only; 3 lost both ER/PR and HER2); one of 33 (3%) ER/PR-negative receptor/HER2-positive primaries (gained ER); and 7 of 39 (18%) triple-negative primaries (5 gained ER/PR and 2 gained HER2).
The purpose of this study was to determine expression profiles of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in breast cancer brain metastasis (BCBM) and the existence of discordance between primary breast cancer and brain metastasis.
By comparing gene expression profiles of Estrogen Receptor negative (ER-) primary breast tumors between patients who developed metastasis to brain and to organs other than brain, we found that T lymphocytes promote the formation of brain metastases.
Brain metastases from 3/4 (75%) TN, 1/1 (100%) estrogen receptor positive (ER<sup>+</sup>), and 5/9 (55.5%) HER2<sup>+</sup> clinical subtypes were established as transplantable BM-PDXs.
In total, 20 cases of primary breast cancer tissue and resected BrM (10 estrogen receptor [ER]-negative and 10 ER-positive) from 2 academic institutions were included.
When considered as continuous variables, ER and AR showed greater expression in primary tumors in comparison with brain metastases (p=0.013 and p=0.032, respectively).In our series, AR predicts brain involvement, with a 9.5 times higher propensity for AR-negative EOC.
All anti-estrogen treated breast tumors lost the estrogen receptor expression in the brain metastases, whereas no Her2/neu conversions occurred after treatment with trastuzumab.
Importantly, concomitant high expression of BST-2 with sLex defined a sub-group of patients with ER-negative tumours displaying higher risks of liver and brain metastasis and a 3-fold decreased survival rate.
Six ESR1 mutations (K303R, S463P, Y537C, Y537N, Y537S, D538G) were assessed by digital droplet PCR (ddPCR), with lower limits of detection of 0.05% to 0.16%, in primary tumors (n = 43), bone (n = 12) and brain metastases (n = 38), and cfDNA (n = 29).
We investigated the status of estrogen receptor alpha (ERα), progesterone receptor (PR), and epidermal growth factor receptor 2 (HER2) in primary tumor and in the corresponding brain metastases in a consecutive series of breast cancer patients.