Abstract 5203
Background
Breast cancers display substantial inter/intra-tumor heterogeneity. While numerous fusion genes have been identified, most are found to be subclonal, passenger alterations. To discover fusion genes which drive tumor progression and metastasis, we performed RNA-sequencing of matched primary and metastatic breast cancer samples.
Methods
RNA-sequencing was performed from sixteen patients matched primary-recurrent tumor tissue and RNA-sequencing data was successfully achieved from sixteen primary tumors and eight recurrent tumors. DeFuse program was used to identify fusion transcripts (FT).
Results
Among the sixteen patients, six were hormone receptor positive, three were HER2 positive and seven were triple negative tumors. Three cases displayed loco-regional recurrence only and other patients had distant metastases. Overall, 516 fusion transcripts were identified. Mean numbers of fusions in primary and recurred tumors were 28 and 14.6 FTs per sample. Numbers of fusions were greater in two cases with BRCA1 pathogenic germline mutations while no significant differences were observed across subtypes. Novel inter-chromosomal fusion transcript, BCL2-ESR1, CSMD1-ESR1 and HPGDS-ESR1 were found in one hormone receptor positive patient’s metastasis and/or primary tumor. All fusions resulted in preservation of the DNA-binding domain and ligand-binding domain (exon4-10) of the ESR1 gene, with high ESR1 FPKM expression value. Fusions of ERBB2-, MALAT1- and CDK6- genes were found. Among the identified FTs, three cases harbored a previously reported recurrent fusion transcript EEF1DP3-FRY.
Conclusions
RNA sequencing revealed numerous fusion transcripts. Among them we found novel fusions including ESR1 fusions which need further validation and functional annotation to confirm their role in tumor progression and metastasis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Asan Medical Center.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5612 - Evaluation of germ line mutational status among women with triple-negative breast cancer in Russia
Presenter: Elena Shagimardanova
Session: Poster Display session 2
Resources:
Abstract
4142 - Association of derived neutrophil-to-lymphocyte ratio (dNLR) with pathological complete response (pCR) after neoadjuvant chemotherapy (CT)
Presenter: Alberto Ocaña
Session: Poster Display session 2
Resources:
Abstract
1733 - Competing nomogram for late-period breast cancer-specific death in patients with early-stage hormone receptor-positive breast cancer
Presenter: Jianfei Fu
Session: Poster Display session 2
Resources:
Abstract
1978 - A Nomogram to Predict Pathologic Complete Response of Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Based on Simple Blood Indicators
Presenter: Fanrong Zhang
Session: Poster Display session 2
Resources:
Abstract
3062 - Identification of GSTP1 transferred by extracellular vesicles responsible for adriamycin-resistance in breast cancer cells
Presenter: Sujin Yang
Session: Poster Display session 2
Resources:
Abstract
5274 - Expression of X-linked Inhibitor of Apoptosis Protein (XIAP) and its Association with Clinicopathological Parameters in Invasive Breast Cancers
Presenter: Gayathri Devi
Session: Poster Display session 2
Resources:
Abstract
1324 - The prognostic significance of preoperative tumor marker (CEA, CA15-3) elevation in breast cancer patients
Presenter: Soo Youn Bae
Session: Poster Display session 2
Resources:
Abstract
4877 - Correlation of clinical and pathological features with the tumour microenvironment in DCIS. An institutional experience
Presenter: Ann Eapen
Session: Poster Display session 2
Resources:
Abstract
2471 - Correlation between radiologic complete response (rCR) in contrast-enhanced magnetic resonance imaging (CE-MRI) after neoadjuvant chemotherapy for early breast cancer and pathologic complete response and their impact in recurrence-free survival
Presenter: Ariadna Gasol Cudos
Session: Poster Display session 2
Resources:
Abstract
2632 - Ring-like uptake appearance on dedicated breast positron emission tomography before chemotherapy predicts outcome of neoadjuvant chemotherapy in breast cancer
Presenter: Norio Masumoto
Session: Poster Display session 2
Resources:
Abstract