Abstract 4499
Background
Several lines of evidence suggest the involvement of CCND1 and FGFR1 genes in determining breast cancer (BC) resistance to endocrine therapy, however these assumptions still require a validation in clinical data sets.
Methods
This study included 138 tumors from patients with metastatic BC who received first-line endocrine therapy with aromatase inhibitors (AI, n = 69), tamoxifen (n = 65), goserelin (n = 2) or a combination of goserelin and tamoxifen (n = 2). DNA extracted from formalin-fixed paraffin-embedded archival specimens was tested for CCND1 and FGFR1 amplification by digital droplet PCR.
Results
CCND1 and FGFR1 status was successfully determined in 134 tumors. CCND1 and FGFR1 amplification was detected in 24 (18%) and 28 (21%) informative cases, respectively; 9 carcinomas had concurrent alterations of two genes. Amplifications were more common in less differentiated tumors (G1: 1/18 (6%) vs. G2-3: 34/86 (40%); p = 0.005, Fisher’s exact test). Median disease-free survival in patients receiving AI with CCND1 amplification was shorter than in cases with the normal gene status (12.3 vs. 14.9 months; p = 0.014, log rank test). Objective response to aromatase inhibitors was observed in 2/13 (15%) BC with FGFR1 amplification compared to 22/46 (48%) tumors with the normal FGFR1 gene copy number (p = 0.054). Noteworthy, among patients receiving AI, CCND1 and/or FGFR1 amplification occurred in 5 out of 7 (71%) women with progressive disease compared to only 4 in 23 (17%) patients with objective response to therapy (p = 0.01). Meanwhile, none of 5 tumors showing resistance to tamoxifen harbored CCND1 or FGFR1 amplification.
Conclusions
The presence of CCND1 and/or FGFR1 amplification is associated with worse results of AI therapy in breast cancer patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Russian Foundation for Basic Research (grant 17-04-01281).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1058 - Assessment of CPS+EG, Neo-Bioscore and modified Neo-Bioscore in breast cancer patients treated with preoperative systemic therapy: a multicenter cohort study
Presenter: LING XU
Session: Poster Display session 2
Resources:
Abstract
1156 - The concordance of treatment decision guided by Oncotype and the PREDICT tool in early stage breast cancer
Presenter: Hadar Goldvaser
Session: Poster Display session 2
Resources:
Abstract
3447 - Influence of first treatment delay on survival among breast cancer subtypes
Presenter: Irene Zarcos Pedrinaci
Session: Poster Display session 2
Resources:
Abstract
3505 - Clinical features of early-stage (I-III) triple-negative breast cancer (TNBC) patients with tumors exhibiting low-overall change in molecular profile after neoadjuvant therapy.
Presenter: Nour Abuhadra
Session: Poster Display session 2
Resources:
Abstract
5442 - Meta-analysis in HER2+ early breast cancer therapies and cost-effectiveness in a Brazilian perspective
Presenter: Marcos Magalhaes
Session: Poster Display session 2
Resources:
Abstract
1570 - Anti-mullerian hormone (AMH) levels and antral follicle counts (AFC) may predict ovarian reserves before systemic chemotherapy (SC) in women with breast cancer(BC); a prospective clinical study
Presenter: Cetin Ordu
Session: Poster Display session 2
Resources:
Abstract
2698 - Prognosis of selected triple negative apocrine breast cancer patients who did not receive adjuvant chemotherapy.
Presenter: Giuseppe Cancello
Session: Poster Display session 2
Resources:
Abstract
3104 - Novel Blood Based Circulating Tumor Cell Biomarker For Breast Cancer Detection
Presenter: Chun-Yu Liu
Session: Poster Display session 2
Resources:
Abstract
4631 - Multi-Gene Prognostic Signatures and Prediction of Pathological Complete Response of ER-Positive HER2-Negative Breast Cancer Patients to Neo-Adjuvant Chemotherapy
Presenter: Claudia Mazo
Session: Poster Display session 2
Resources:
Abstract
4632 - Impact of menopause status on breast cancer outcomes and amenorrhea incidence during adjuvant tailored dose dense chemotherapy
Presenter: Andri Papakonstantinou
Session: Poster Display session 2
Resources:
Abstract