Abstract GS2-02: Acquired activating mutations in RTKs confer endocrine resistance in ER+ metastatic breast cancer through ER-reprogramming, MAPK signaling, and an induced stem-like cell state

2020 ◽  
Author(s):  
Ofir Cohen ◽  
Pingping Mao ◽  
Utthara Nayar ◽  
Jorge E Buendia-Bue ◽  
Dewey Kim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Mapk Signaling ◽  
Cell State ◽  
Activating Mutations

The association of HER2 low expression with the efficacy of CDK4/6 inhibitor in hormone receptor positive HER2 negative metastatic breast cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1052-1052
Author(s):  
Kelvin K H Bao ◽  
Leone Sutanto ◽  
Shirley S W Tse ◽  
Ka Man Cheung ◽  
Jeffrey C H Chan
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Cox Regression ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Rank Test ◽  
Her2 Expression ◽  
Disease Extent ◽  
Potential Marker ◽  
Low Expression

1052 Background: Markers for the efficacy of CDK4/6 inhibitor in estrogen receptor (ER) positive, HER2 negative advanced breast cancer are limited. The bidirectional crosstalks that exist between ER and HER2 pathways contribute to endocrine resistance. We investigated the association between low levels of HER2 expression and the clinical outcome of patients with ER+ HER2- metastatic breast cancer (MBC) treated with CDK4/6 inhibitors. Methods: We identified consecutive patients with ER+ HER2- MBC who received CDK4/6 inhibitor plus either letrozole or fulvestrant between Mar 2017 - Jun 2020 from an institutional cancer registry. HER2-low expression was defined as IHC score 1+, or 2+ with a negative ISH. Progression-free survival (PFS) was defined as the time from the initiation of CDK4/6 inhibitor to the date of radiological or clinical progression, or death. The relationship between HER2 expression levels and PFS was evaluated using log-rank test and multivariable Cox regression modelling. Results: 106 women with MBC were eligible for analysis. Median age at treatment was 58 (23.0-91.4). The majority received palbociclib (84%) while the rest received ribociclib. CDK4/6 inhibitor was used as first-line treatment in 50.9% of cases. Most tumors were of ductal histology (83%) and progesterone receptor (PgR) positive (84.9%), and 22.6% of the patients had bone-only disease. 77.3% of cases were considered HER2-low expressing. HER2-low expression was associated with a significantly shorter PFS compared with HER2 IHC 0 counterpart (median, 8.9 vs 18.8 months, p= 0.014). In multivariate analysis, HER-2 low expression remained significantly associated with an inferior PFS (HR 1.96, 95%CI 1.03-3.75, p= 0.041) after adjusting for the line of treatment, PgR status and disease extent (bone only vs extra-osseous disease). Conclusions: In patients with ER+ HER2- MBC treated with CDK4/6 inhibitors, HER2-low expression was associated with an inferior PFS, and may serve as a potential marker candidate for CDK4/6 inhibitor efficacy. As novel anti-HER2 antibody-drug conjugates demonstrated efficacy in HER2-low expressing MBC, coupled with the emerging evidence for the combination of CDK4/6 inhibitors with anti-HER2 agents, this HER2-low expression subgroup warrants prospective evaluations in future trials.

The effect of trastuzumab therapy on clinical benefit from fulvestrant treatment for metastatic estrogen receptor-positive breast cancer patients.

2014 ◽  
Vol 32 (26_suppl) ◽  
pp. 155-155
Author(s):  
Mahmoud Charif ◽  
Elyse E. Lower ◽  
Diane Kennedy ◽  
Harriet Kumar ◽  
Shugufta Khan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Metastatic Breast Cancer ◽  
Clinical Benefit ◽  
Primary Tumor ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Primary Tumors ◽  
Duration Of Therapy ◽  
Her 2

155 Background: Overexpression of HER2/neu is associated with tamoxifen resistance in breast cancer (Osborne CK et al. J Natl Canc Inst 2003; 95:353-361). However pts may present with both estrogen receptor (ER) and HER2/neu + tumors. The benefit of adding fulvestrant to trastuzumab is unclear. The objective of the study was to determine the effect of trastuzumab on fulvestrant therapy. Methods: This was an IRB approved record review of patients (pts) from three medical oncologists with biopsy-proven ER+ metastatic breast cancer treated with fulvestrant who also had their primary tumor tested for HER2/neu. Demographic data collected included age at diagnosis, type and stage of cancer, original and metastatic ER, progesterone receptor (PR), and HER-2/neu biomarkers, and site(s) of metastasis, and primary local and systemic treatment. All pts with HER-2/neu + primary tumors received trastuzumab. The duration of fulvestrant therapy was calculated. Time to clinical disease progression on fulvestrant was measured as a surrogate for duration of clinical benefit. Results: Eighty-five metastatic ER+ fulvestrant treated breast cancer pts with known primary tumor HER2/neu status were identified and the duration of therapy calculated. All eleven (13%) pts with documented HER2/neu + primary tumors received trastuzumab. The duration of therapy for HER2/neu + pts (772 (51-1911) days (median (range)) was longer than HER2/neu negative pts (360 (60-2,739) days, p=0.059). The median duration of fulvestrant therapy was 425 days. Pts with HER2/neu + tumors were more likely to be treated beyond the median fulvestrant therapy with an odds ratio of 6.2 (1.26 to 30.92 95% confidence interval, p=0.0249). Conclusions: Trastuzumab plus fulvestrant therapy was associated with a more prolonged clinical response than fulvestrant alone in pts with metastatic breast cancer. This synergism may be due to the effect of trastuzumab inhibiting the activation of transcriptional coactivator MED1, a recently discovered key crosstalk point between HER2/neu and ER signaling pathways in mediating endocrine resistance (Cancer Res 2012;72(21):5625;PLoS One 2013; 8:e70641).

scholarly journals Self-renewal of CD133hi cells by IL6/Notch3 signalling regulates endocrine resistance in metastatic breast cancer

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Pasquale Sansone ◽  
Claudio Ceccarelli ◽  
Marjan Berishaj ◽  
Qing Chang ◽  
Vinagolu K. Rajasekhar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Self Renewal

scholarly journals Liquid Biopsy: New Tool to Overcome CDKi Resistance Mechanism in Luminal Metastatic Breast Cancer

2021 ◽  
Author(s):  
Miriam González-Conde ◽  
Celso Yanez ◽  
Rafael López-López ◽  
Clotilde Costa
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Cancer Patients ◽  
Liquid Biopsy ◽  
Hormone Receptors ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Luminal Breast Cancer ◽  
Breast Cancer Patients ◽  
Her2 Breast Cancer

Breast cancer is the most commonly diagnosed cancer in women worldwide. Approximately, 70 % of breast cancer patients express hormone receptors (HR) (Luminal subtype). Adjuvant endocrine treatments are the standard of care in HR+/HER2- breast cancer. Over time, about 50% of those patients develop endocrine resistance and metastatic breast cancer. Cyclin-dependent kinase inhibitors (CDKi) in combination with an aromatase inhibitor or fulvestrant have demonstrated superior efficacy increasing progression-free survival, with a safe toxicity profile, in HR+/HER2- metastatic breast cancer patients. CDKi blocks kinases 4/6 ATP-binding domain preventing G1/S cell cycle transition. Despite this, not all patients respond to CDKi and those who respond, finally develop resistance to combination therapy. Different studies, in tumour tissue or cell lines, have tried to elucidate the mechanisms underlying this progression, but there are still no conclusive data. In the last few years, liquid biopsy has contributed relevant information to this knowledge. Liquid biopsy can be performed in real-time, non-invasively and be repeated whenever needed. Circulating tumour material are potential prognostic markers in metastatic luminal breast cancer to determine patient prognosis, monitor disease and treatment selection. The objective of this review is to outline the different studies carried out in HR+ metastatic breast cancer patients treated with CDKi plus endocrine therapy using liquid biopsy approaches looking for possible resistance mechanisms.

scholarly journals A single droplet digital PCR for ESR1 activating mutations detection in plasma

2019 ◽  
Author(s):  
Emmanuelle Jeannot ◽  
Lauren Darrigues ◽  
Marc Michel ◽  
Marc-Henri Stern ◽  
Jean-Yves Pierga ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Metastatic Breast Cancer ◽  
Limit Of Detection ◽  
Growth Factor Receptor ◽  
Metastatic Breast ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Plasma Samples ◽  
Activating Mutations

AbstractBackgroundActivating mutations in the estrogen receptor 1 (ESR1) gene are recurrent mechanisms of acquired resistance to aromatase inhibitors (AI), and may be the target of other selective estrogen receptor down-regulators. To assess the clinical utility of monitoring ESR1 resistant mutations, a droplet digital PCR (ddPCR)-based assay compatible with body fluids is ideal due to its cost-effectiveness and quick turnaround.MethodsWe designed a multiplex ddPCR, which combines a drop-off assay, targeting the clustered hotspot mutations found in exon 8, with another pair of probes interrogating the E380Q mutation in exon 5. We assessed its sensitivity in vitro using synthetic oligonucleotides, harboring E380Q, L536R, Y537C, Y537N, Y537S or D538G mutations. Validation of the assay was performed on plasma samples from a prospective study and compared to next generation sequencing (NGS) data.ResultsThe multiplex ESR1-ddPCR showed a high sensitivity with a limit of detection ranging from 0.07 to 0.19% in mutant allele frequency depending on the mutation tested. The screening of plasma samples from patients with AI-resistant metastatic breast cancer identified ESR1 mutations in 29% of them with perfect concordance (and higher sensitivity) to NGS data obtained in parallel. Additionally, this test identifies patients harboring polyclonal alterations. Furthermore, the monitoring of ctDNA using this technique during treatment follow-up predicts the radiological response to palbociclib-fulvestrant.ConclusionThe multiplex ESR1-ddPCR detects, in a single reaction, the most frequent ESR1 activating mutations and is compatible with plasma samples. This method is thus suitable for real-time ESR1 mutation monitoring in large cohorts of patients.Statement of translational relevanceExons 5 and 8 mutations in ESR1 are recurrent mechanisms of resistance to aromatase inhibitors (AI) in estrogen receptor (ER)-positive metastatic breast cancer and may be targeted by selective ER down-regulators. We implemented a novel droplet digital PCR, which allows for the detection of the most frequent ESR1 mutations in circulating cell-free DNA. In prospectively collected plasma samples, ESR1 mutations were found in 29% of AI-resistant patients, with excellent concordance and higher sensitivity to next generation sequencing. Moreover, circulating ESR1 mutations appear to be reliable markers for ctDNA monitoring in order to predict treatment response. Ultimately, the short turnaround time, high sensitivity and limited cost of the ESR1-ddPCR are compatible with repeated samplings to detect the onset of resistance to AI before the radiological progression. This opens a window of opportunity to develop new clinical strategies for breast cancer hormone therapy, as tested in an ongoing phase 3 trial.List of abbreviationsAIAromatase InhibitorcfDNACell-free DNActDNACirculating tumor DNAddPCRDroplet digital PCRER+ HER2-MBCER+ HER2-negative Metastatic Breast CancerEREstrogen ReceptorER+Estrogen Receptor positiveLOBLimit of blankLODLimit of detectionMAFMutant Allele FrequencyPBMCPeripheral blood mononuclear cellsPDProgressive diseaseSDStandard deviationToPTime of progressionWTWild typeHuman genesESR1: Estrogen Receptor 1HER2: Human Epidermal Growth Factor Receptor 2EGFR: Epithelial Growth Factor ReceptorKRAS: KRAS proto-oncogene, GTPaseBRAF: B-Raf Proto-Oncogene, Serine/Threonine kinase

scholarly journals The PI3K/AKT/mTOR and CDK4/6 Pathways in Endocrine Resistant HR+/HER2− Metastatic Breast Cancer: Biological Mechanisms and New Treatments

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1242 ◽  
Author(s):  
Daniele Presti ◽  
Erica Quaquarini
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Endocrine Resistance ◽  
Growth Factor Receptor ◽  
Metastatic Breast ◽  
Progression Free Survival ◽  
Mtor Inhibitors ◽  
Endocrine Treatment ◽  
Response Predictors ◽  
New Treatments

Endocrine-based treatments are the normal standard-of-care in women with hormone receptor-positive/Human Epidermal growth factor Receptor 2-negative metastatic breast cancer. Despite the well-known efficacy of these drugs as first-line therapies, about 50% of women develop endocrine resistance and disease progression. The treatment of these patients has represented one of the most important research fields in the last few years, with several multicenter phase II/III trials published or still ongoing. Novel therapies, such as cyclin-dependent kinase (CDK)4/6 and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) inhibitors, have significantly changed the prognosis of patients progressing to a previous endocrine treatment, allowing a great benefit in terms of progression-free survival and, in some cases, of overall survival. However, identifying response predictors is essential for the rational use of these drugs to avoid unnecessary toxicity and costs, and to ensure the optimal therapeutic sequence is used. In this review, we analyze the PI3K/AKT/mTOR and CDK4/6 pathways and their roles in endocrine resistant metastatic breast cancer. We then focus on the new treatments developed and the roles of these drugs in overcoming endocrine resistance, describing the latest clinical trials that led to the approval of the drugs in clinical practice.

scholarly journals Are We Ready to Use ESR1 Mutations in Clinical Practice

Breast Care ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. 309-313 ◽  
Author(s):  
Rinath Jeselsohn
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Aromatase Inhibitors ◽  
Endocrine Resistance ◽  
Metastatic Breast ◽  
Circulating Tumor Dna ◽  
Breast Cancers ◽  
Poor Overall Survival ◽  
Treatment Naïve ◽  
Esr1 Mutations

The recurrent ligand-binding domain ESR1 mutations are an important mechanism of endocrine resistance in estrogen receptor-positive (ER+) metastatic breast cancer. These mutations evolve under the selective pressure of endocrine treatments and are rarely found in treatment-naïve ER+ breast cancers. Preclinical studies showed that these mutations lead to ligand-independent activity facilitating resistance to aromatase inhibitors and relative resistance to tamoxifen and fulvestrant. Retrospective analyses of ESR1 mutations in baseline plasma circulating tumor DNA from clinical trials suggest that these mutations are prognostic of poor overall survival and predictive of resistance to aromatase inhibitors in metastatic disease. Larger datasets and prospective studies to confirm these results are lacking. In addition, response to other standard treatments for metastatic breast cancer in the presence of the ESR1 mutations is unknown, and studies to determine the optimal treatment combinations for patients with ESR1 mutations are also needed.

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