Genomic profiling of breast cancer brain metastases reveals targetable alterations.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 2525-2525
Author(s):  
Sheheryar Kairas Kabraji ◽  
Liam F. Spurr ◽  
Melissa E Hughes ◽  
Yvonne Y. Li ◽  
Jose Pablo Leone ◽  
...  

2525 Background: Genomic characterization of breast cancer brain metastases (BCBMs) has thus far been limited. The objective of this study was to describe the landscape of genomic alterations in patients (pts) with BCBMs. Methods: Targeted next-generation DNA sequencing of > 300 cancer-related genes (OncoPanel) was prospectively performed on primary and metastatic (met) tumors in 321 pts with a diagnosis of BCBM between August 2016 and April 2019 at Dana-Farber Cancer Institute (table). Enrichment analysis of genomic alterations was performed using a two-sided Fisher exact test and differences in tumor mutation burden (TMB) between groups were assessed using two-sided Mann-Whitney U test. Multiple comparison correction was performed using the Benjamini-Hochberg procedure. Results: All subtypes were represented in BCBM (25 HR+/HER2-; 24 HR+/HER2+; 27 HR-/HER2+; 18 TNBC; 5 unknown; n = 99) and extracranial (EC) samples: (96 HR+/HER2-; 32 HR+/HER2+; 22 HR-/HER2+; 41 TNBC; 31 unknown; n = 222). BCBMs were found most commonly to have mutations or copy number alterations in TP53, ERBB2, PIK3CA, GATA3, PTEN, ESR1, CDH1, BRCA2, ARID1A, BRCA1 (>5% frequency, table). Two pts acquired ERBB2 amplification (amp) between the matched primary breast sample and brain met. In pair-wise comparisons of BCBMs to unmatched primaries or EC mets, only ERBB2 amp was significantly enriched (table, † = adjusted p < 0.05). There was no significant difference in TMB between BCBM and EC mets (median 9.12 vs 7.26, p = 0.15). In contrast, TMB was significantly higher in BCBMs compared to unmatched primaries (median 9.12 vs 7.26, p=0.005). Conclusions: BCBMs display similar mutations and copy number alterations compared to primary tumors and EC mets in pts with BCBM. These data suggest that BCBMs contain actionable genomic alterations that are most often also reflected in EC disease. Alterations in ERBB2, PIK3CA/PTEN, and BRCA1/2 represent potentially targetable alterations in pts with BCBM. [Table: see text]

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 2526-2526
Author(s):  
Gaia Griguolo ◽  
Anna Tosi ◽  
Valentina Guarneri ◽  
Maria Vittoria Dieci ◽  
Susan Fineberg ◽  
...  

2526 Background: Despite clinical implications, the complexity of brain metastases (BM) immune microenvironment in breast cancer (BC) patients is poorly understood. Multiplex immunofluorescence (mIF), a novel imaging technique allowing simultaneous visualization and quantification of several IF labeled proteins while maintaining spatial information, holds promise to comprehensively describe BCBM immune microenvironment, potentially providing valuable information to improve treatment. Methods: Clinical data and archival BM samples were collected for 60 BC patients undergoing neurosurgery (2003-2018) at three institutions. BM immune contexture was characterized using a custom mIF panel, including cell subtyping (CD4, CD8, FOXP3, CD68), activation (Granzyme B) and localization (keratin for tumor recognition) markers. Mean immune cell density (cells/mm2) for each sample was determined by digital image analysis and classified in tumor and stroma areas. Associations between immune subpopulations, BC subtype and overall survival from BM diagnosis (OS) were studied. Results: Up to date, 30 BCBM samples have been analyzed; 33% HR+/HER2-, 20% HR-/HER2+, 10% HR+/HER2+, 37% HR-/HER2-. At a median follow-up of 46 months, BC subtype was the only clinical variable associated with OS (longest for HER2+ and shortest for HR-/HER2-, log-rank p = 0.002). In the total sample area, no significant difference in immune cell densities was observed according to BC subtype. In the tumor area, HR+/HER2- tumors showed higher densities of CD8+ and CD68+ cells compared to other subtypes (p = 0.036 and p = 0.016, respectively). In stroma, HR-/HER2- tumors presented numerically higher densities of CD4+ and FOXP3+ cells and higher ratio of CD4/CD8 and FOXP3/CD8 ratio (not statistically significant). Higher CD4/CD8 and FOXP3/CD8 ratio in the stroma was significantly associated with worse OS, even after correction by BC subtype (Table). Conclusions: In BCBM, immune infiltrate differs according to BC subtype. Preliminary results suggest that a more tolerogenic immune microenvironment is associated with worse OS and might represent a target for optimization of immunotherapy for these patients. Updated results for all 60 patients will be presented. [Table: see text]


2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
N Cosgrove ◽  
D Vareslija ◽  
SJ Furney ◽  
S Oesterreich ◽  
AV Lee ◽  
...  

Abstract Introduction The incidence of brain metastases is increasing despite longer survival rates for patients with advanced breast cancer. The identification of novel therapeutic targets for these patients is an urgent unmet clinical need. Sequencing of metastatic tumours have largely focused on mutations however gene fusions have an important, yet underappreciated role in tumorigenesis and disease progression. In this study, we investigate the role of gene fusions in brain metastatic disease and their impact on altered therapeutic responses. Method RNA sequencing was performed on the largest reported cohort of patient matched primary and resected brain metastatic tumours (45 patients n=90 samples). Expressed gene fusions were detected computationally using STAR-Fusion and Arriba. Result We identified differential gene fusion burden in brain metastatic tumours (medium of 58) vs. primary breast tumours (medium of 38) (p &lt; 0.05). Enrichment for fusions in pathways associated with tumour cell plasticity and proliferation with recurrent fusions in known cancer driver genes related to MAPK, HER signaling identified. Of note, a fusion in CDK12 is of clinical importance. Increased genomic alterations and over expression of CDK12 is associated with brain metastases free survival in an independent cohort of primary breast tumours with a recorded history of brain metastases. It has been proposed that inhibition of CDK12 may induce BRCAness in tumours making them sensitive to PARP inhibition. Conclusion These results highlight the significant role of gene fusions in breast cancer brain metastases. Abbreviations MAPK Mitogen Activated Protein Kinase, HER Human Epidermal Receptor, CDK12 Cyclin Dependent Kinase 12 Take-home message We highlight the significant role of gene fusions in breast cancer brain metastases and offer specific actionable genomic alterations to be exploited.


2020 ◽  
Vol 22 (8) ◽  
pp. 1173-1181 ◽  
Author(s):  
Alexander F C Hulsbergen ◽  
An Claes ◽  
Vasileios K Kavouridis ◽  
Ali Ansaripour ◽  
Claudine Nogarede ◽  
...  

Abstract Background Breast cancer (BC) brain metastases (BM) can have discordant hormonal or human epidermal growth factor receptor 2 (HER2) expression compared with corresponding primary tumors. This study aimed to describe incidence, predictors, and survival outcomes of discordant receptors and associated subtype switching in BM. Methods BCBM patients seen at 4 tertiary institutions who had undergone BM resection or biopsy were included. Surgical pathology reports were retrospectively assessed to determine discordance between the primary tumor and the BCBM. In discordant cases, expression in extracranial metastases was also assessed. Results In BM from 219 patients, prevalence of any discordance was 36.3%; receptor-specific discordance was 16.7% for estrogen, 25.2% for progesterone, and 10.4% for HER2. Because estrogen and progesterone were considered together for hormonal status, 50 (22.8%) patients switched subtype as a result; 20 of these switches were HER2 based. Baseline subtype predicted switching, which occurred in up to 37.5% of primary HR+ patients. Moreover, 14.8% of initially HER2-negative patients gained HER2 in the BM. Most (63.6%) discordant patients with extracranial metastases also had discordance between BM and extracranial subtype. Loss of receptor expression was generally associated with worse survival, which appeared to be driven by estrogen loss (hazard ratio = 1.80, P = 0.03). Patients gaining HER2 status (n = 8) showed a nonsignificant tendency toward improved survival (hazard ratio = 0.64, P = 0.17). Conclusions In this multicenter study, we report incidence and predictors of subtype switching, the risk of which varies considerably by baseline subtype. Switches can have clinical implications for prognosis and treatment choice.


2018 ◽  
Vol 36 (6) ◽  
pp. 543-553 ◽  
Author(s):  
Daniel G. Stover ◽  
Heather A. Parsons ◽  
Gavin Ha ◽  
Samuel S. Freeman ◽  
William T. Barry ◽  
...  

Purpose Cell-free DNA (cfDNA) offers the potential for minimally invasive genome-wide profiling of tumor alterations without tumor biopsy and may be associated with patient prognosis. Triple-negative breast cancer (TNBC) is characterized by few mutations but extensive somatic copy number alterations (SCNAs), yet little is known regarding SCNAs in metastatic TNBC. We sought to evaluate SCNAs in metastatic TNBC exclusively via cfDNA and determine if cfDNA tumor fraction is associated with overall survival in metastatic TNBC. Patients and Methods In this retrospective cohort study, we identified 164 patients with biopsy-proven metastatic TNBC at a single tertiary care institution who received prior chemotherapy in the (neo)adjuvant or metastatic setting. We performed low-coverage genome-wide sequencing of cfDNA from plasma. Results Without prior knowledge of tumor mutations, we determined tumor fraction of cfDNA for 96.3% of patients and SCNAs for 63.9% of patients. Copy number profiles and percent genome altered were remarkably similar between metastatic and primary TNBCs. Certain SCNAs were more frequent in metastatic TNBCs relative to paired primary tumors and primary TNBCs in publicly available data sets The Cancer Genome Atlas and METABRIC, including chromosomal gains in drivers NOTCH2, AKT2, and AKT3. Prespecified cfDNA tumor fraction threshold of ≥ 10% was associated with significantly worse metastatic survival (median, 6.4 v 15.9 months) and remained significant independent of clinicopathologic factors (hazard ratio, 2.14; 95% CI, 1.4 to 3.8; P < .001). Conclusion We present the largest genomic characterization of metastatic TNBC to our knowledge, exclusively from cfDNA. Evaluation of cfDNA tumor fraction was feasible for nearly all patients, and tumor fraction ≥ 10% is associated with significantly worse survival in this large metastatic TNBC cohort. Specific SCNAs are enriched and prognostic in metastatic TNBC, with implications for metastasis, resistance, and novel therapeutic approaches.


2011 ◽  
Vol 29 (27_suppl) ◽  
pp. 9-9
Author(s):  
M. J. M. Magbanua ◽  
E. Sosa ◽  
R. Roy ◽  
L. Eisenbud ◽  
J. Scott ◽  
...  

9 Background: We developed a novel approach to isolate circulating tumor cells (CTCs) via immunomagnetic enrichment followed by fluorescence activated cell sorting (IE/FACS) and examined copy number alterations in these cells. Methods: Magnetic beads coated with EpCAM mAb were added to blood to enrich for tumor cells. Enriched samples were then subjected to FACS analysis using differentially labeled mAbs to distinguish tumor cells (EpCAM+) from leukocytes (CD45+) during sorting. DNA from isolated tumor cells was subjected to whole genome amplification (WGA) and copy number analysis via array comparative genomic hybridization (aCGH). The assay was evaluated in CTCs from 5 MBC pts with matched archival primary tumors and later extended to an additional 176 MBC pts, 97 of which were successfully profiled. Results: Comparison of CTCs with matched archival primary tumors confirmed shared lineage with notable divergence. In addition, serial testing of CTCs confirmed reproducibility, and indicated genomic change over time. Genomic profiling of CTCs from 102 MBC pts revealed a wide range of copy number alterations including those previously reported in breast cancer. Comparison with a published aCGH dataset of primary breast tumors revealed similar frequencies of recurrent genomic copy number aberrations. Conclusions: It is feasible to isolate CTCs away from hematopoietic cells with high purity via IE/FACS and profile them via aCGH analysis following WGA. Our approach may be utilized to explore genomic events involved in cancer progression and to monitor therapeutic efficacy of targeted therapies in clinical trials in a relatively non-invasive manner. This work was supported by grants from the CALGB, BCRF, TBCRC (Avon, Komen), EDRN and U54.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e20659-e20659
Author(s):  
Zorica Tomasevic ◽  
Zeljko Kovac ◽  
Zoran Tomasevic

e20659 Background: BCBM development predicts short survival for majority of pts. However, 10%, of pts survive up to 2 yrs, and some of those pts has extended survival to more than 2 yrs after BM. Whether there are differences between pts in those arbitrary determined subgroups with prolonged survival is still unknown. The aim of this paper is to analyze and compare characteristics of BCBM pts with survival after BM (BMs) between ≥ 12 - 24 months and ≥ 25 month. Methods: A 193 consecutive BCBM pts have been registered during 5 yrs (January 2008-December 2012). All BM were confirmed by CT/MRI. All pts underwent BM treatment: WBRT 160 (83%); postoperative WBRT in 32 pts (17 %); gamma knife in 7 pts (3,6 %). BMs is known for 169 pts and was median 5,5 months (range 1-72+ months). Only pts with BMs ≥ 12 months were considered for this analysis. Results: 39/169 pts (23%) with median BMs 19 months (range 12-72+) were identified and divided in 2 groups (see Table). MBC in other organ sites, predominantly non visceral, was present in 45% pts (A) and in 40% (B), at the time of BM diagnose. There was no statistically significant difference between group A and B. Conclusions: Despite BM, a subgroup of pts still has indolent MBC course with median BMs of 19 months, and 6% has BMs of median 35 months. There were no statistically significant difference between standard clinical/pathological parameters Therefore, other characteristics, both patients and BC/BM must be considered. Better understanding of crucial characteristics of this subgroup of BCBM pts, is needed because these pts might potentially represents the best candidates for future BM preventive strategies. [Table: see text]


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 378
Author(s):  
Sofia Galego ◽  
Linda Azevedo Kauppila ◽  
Rui Malhó ◽  
José Pimentel ◽  
Maria Alexandra Brito

Myocyte enhancer factor 2C (MEF2C) is increasingly expressed in mice along with breast cancer brain metastases (BCBM) development. We aim to ascertain MEF2C expression in human BCBM, establish the relationship with disease severity, disclose the involvement of vascular endothelial growth factor receptor-2 (VEGFR-2) and β-catenin, also known as KDR and CTNNB1, respectively, and investigate if matched primary tumors express the protein. We studied resected BCBM for the expression of MEF2C, VEGFR-2, and ß-catenin, as well as proliferation (Ki-67) and epithelial (pan Cytokeratin) markers, and related experimental and clinical data. MEF2C expression was further assessed in matched primary tumors and non-BCBM samples used as controls. MEF2C expression was observed in BCBM, but not in controls, and was categorized into three phenotypes (P): P1, with extranuclear location; P2, with extranuclear and nuclear staining, and P3, with nuclear location. Nuclear translocation increased with metastases extension and Ki-67-positive cells number. P1 was associated with higher VEFGR-2 plasma membrane immunoreactivity, whereas P2 and P3 were accompanied by protein dislocation. P1 was accompanied by β-catenin membrane expression, while P2 and P3 exhibited β-catenin nuclear translocation. Primary BC samples expressed MEF2C in mammary ducts and scattered cells in the parenchyma. MEF2C emerges as a player in BCBM associated with disease severity and VEGFR-2 and β-catenin signaling.


2022 ◽  
Vol 11 ◽  
Author(s):  
Lulu Wang ◽  
Dan Zeng ◽  
Qi Wang ◽  
Li Liu ◽  
Tao Lu ◽  
...  

Brain metastases represent a major cause of mortality among patients with breast cancer, and few effective targeted treatment options are currently available. Development of new biomarkers and therapeutic targets for breast cancer brain metastases (BCBM) is therefore urgently needed. In this study, we compared the gene expression profiles of the brain metastatic cell line MDA-MB-231-BR (231-BR) and its parental MDA-MB-231, and identified a total of 84 genes in the primary screening through a series of bioinformatic analyses, including construction of protein-protein interaction (PPI) networks by STRING database, identification of hub genes by applying of MCODE and Cytohubba algorithms, identification of leading-edge subsets of Gene Set Enrichment Analysis (GSEA), and identification of most up-regulated genes. Eight genes were identified as candidate genes due to their elevated expression in brain metastatic 231-BR cells and prognostic values in patients with BCBM. Then we knocked down the eight individual candidate genes in 231-BR cells and evaluated their impact on cell migration through a wound-healing assay, and four of them (KRT19, FKBP10, GSK3B and SPANXB1) were finally identified as key genes. Furthermore, the expression of individual key genes showed a correlation with the infiltration of major immune cells in the brain tumor microenvironment (TME) as analyzed by Tumor Immune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis (GEPIA), suggesting possible roles of them in regulation of the tumor immune response in TME. Therefore, the present work may provide new potential biomarkers for BCBM. Additionally, using GSEA, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis, we determined the top enriched cellular functions or pathways in 231-BR cells, which may help better understand the biology governing the development and progression of BCBM.


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