Monitoring of PIK3CA and ESR1 mutations in circulating tumor DNA as predictive and prognostic biomarkers in patients with endocrine-resistant ER+/HER2- advanced breast cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13045-e13045
Author(s):  
Jesús Fuentes Antrás ◽  
Vanesa García-Barberán ◽  
Irene Gonzalo ◽  
Fernando Moreno ◽  
Igor López-Cade ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Advanced Breast Cancer ◽  
Endocrine Therapy ◽  
Aromatase Inhibitors ◽  
Endocrine Resistance ◽  
Advanced Breast ◽  
Primary Tumors ◽  
Mutational Status ◽  
Esr1 Mutations

e13045 Background: Combination therapeutic strategies including CDK4/6 inhibitors and an endocrine backbone are the standard of care of treatment for patients with estrogen receptor positive (ER+)/HER2- advanced breast cancer (ABC). Endocrine agents mainly include aromatase inhibitors, which target ER-driven transcription, and fulvestrant, which functions as ER antagonist. PI3K-AKT-mTOR is a key point of resistance to endocrine therapy, activated in 40% of these patients by mutations concentrated in critical regions of PIK3CA, coding for the p110 catalytic subunit α of PI3K. Additionally, 30% of patients previously exposed to non-steroidal aromatase inhibitors develop mutations in the ligand binding domain of ESR1, causing endocrine resistance by constitutive activation of the ER. Furthermore, metastasis and primary tumors may show a highly heterogenous mutational landscape. Monitoring the dynamic changes of these mutations in ctDNA may provide a non-invasive, real-time and accessible tool to convey predictive/prognostic information and guide decisions on sequential endocrine therapies. Methods: Pre-planned interim analysis results of an observational, prospective cohort pilot study to assess the predictive and prognostic value of monitoring PIK3CA and ESR1 mutations in ctDNA of patients with endocrine-resistant ER+/HER2- ABC. We have studied longitudinal liquid biopsies from 30 patients using digital PCR to interrogate PIK3CA mutations (H1047R / E545K) and ESR1 mutations (D538G / Y537S). Blood samples were drawn at the time of progression to endocrine therapy, at 8 weeks of subsequent endocrine line and at new progression. This exploratory analysis will provide preliminary data on clinical homogeneity, treatment regimens, median follow-up and progression-free survival, mutation incidence and intraindividual variation of mutant allele frequency and copy number. The percentage of progressors at 24 weeks of follow-up according to the mutational status will be evaluated by using the Fisher’s exact test. The predictive potential of ctDNA biomarkers will be characterized by ROC curve analysis. Tracking ctDNA mutations to predict endocrine resistance in a real-world setting represents a critical step towards precision medicine in oncology.

scholarly journals Currently Applied Molecular Assays for Identifying ESR1 Mutations in Patients with Advanced Breast Cancer

2020 ◽  
Vol 21 (22) ◽  
pp. 8807
Author(s):  
Nuri Lee ◽  
Min-Jeong Park ◽  
Wonkeun Song ◽  
Kibum Jeon ◽  
Seri Jeong
Keyword(s):  
Breast Cancer ◽  
Advanced Breast Cancer ◽  
Endocrine Therapy ◽  
High Sensitivity ◽  
Digital Pcr ◽  
Advanced Breast ◽  
Sample Type ◽  
Breast Cancers ◽  
Esr1 Mutations ◽  
Next Generation Sequencing Ngs

Approximately 70% of breast cancers, the leading cause of cancer-related mortality worldwide, are positive for the estrogen receptor (ER). Treatment of patients with luminal subtypes is mainly based on endocrine therapy. However, ER positivity is reduced and ESR1 mutations play an important role in resistance to endocrine therapy, leading to advanced breast cancer. Various methodologies for the detection of ESR1 mutations have been developed, and the most commonly used method is next-generation sequencing (NGS)-based assays (50.0%) followed by droplet digital PCR (ddPCR) (45.5%). Regarding the sample type, tissue (50.0%) was more frequently used than plasma (27.3%). However, plasma (46.2%) became the most used method in 2016–2019, in contrast to 2012–2015 (22.2%). In 2016–2019, ddPCR (61.5%), rather than NGS (30.8%), became a more popular method than it was in 2012–2015. The easy accessibility, non-invasiveness, and demonstrated usefulness with high sensitivity of ddPCR using plasma have changed the trends. When using these assays, there should be a comprehensive understanding of the principles, advantages, vulnerability, and precautions for interpretation. In the future, advanced NGS platforms and modified ddPCR will benefit patients by facilitating treatment decisions efficiently based on information regarding ESR1 mutations.

scholarly journals Fulvestrant in advanced breast cancer: evidence to date and place in therapy

2017 ◽  
Vol 9 (7) ◽  
pp. 465-479 ◽  
Author(s):  
Katalin Boér
Keyword(s):  
Breast Cancer ◽  
Advanced Breast Cancer ◽  
Postmenopausal Women ◽  
Endocrine Therapy ◽  
Aromatase Inhibitors ◽  
Hormone Receptor ◽  
Single Agent ◽  
Advanced Breast ◽  
Hormone Receptor Positive ◽  
Metastatic Setting

Breast cancer is a classical hormone-dependent tumour; therefore, endocrine therapy is the mainstay of treatment for hormone receptor-positive, human epidermal growth factor 2-negative advanced breast cancer. Until recently, classical endocrine agents such as tamoxifen, steroidal and nonsteroidal aromatase inhibitors and fulvestrant have been widely used in postmenopausal patients to treat locally advanced or metastatic disease. However, for patients with this subtype of breast cancer, the landscape of endocrine therapy is rapidly changing. Therapies targeting oestrogen modulation have evolved in recent years following the introduction of targeted agents, mTOR and CDK 4/6 inhibitors that are administered in combination with hormone therapy. As a result, options for endocrine therapy have expanded in recent years, and a variety of single-agent or combinations of targeted drugs and endocrine therapies are accepted. Fulvestrant is a selective oestrogen receptor downregulator (SERD) which was introduced to clinical practice in 2002, initially with the indication to treat postmenopausal women with hormone-receptor-positive advanced breast cancer as second-line therapy postdisease progression after aromatase inhibitors or tamoxifen. Additionally, fulvestrant has also been shown to be active in patients previously untreated with endocrine therapy, either both in the neoadjuvant and the metastatic setting, alone or in combination with other targeted therapies. Currently, the standard dose is 500 mg, which is administered with a loading dose. Fulvestrant received a new FDA indication in December 2016, in combination with palbociclib, both in pre/peri/postmenopausal women with breast cancer progressing after endocrine therapy. This manuscript aims to give an overview of new efficacy data and the current role of fulvestrant in the systemic therapy of hormone-receptor-positive advanced breast cancer, in the context of other available therapeutic modalities.

scholarly journals MCM3 upregulation confers endocrine resistance in breast cancer and is a predictive marker of diminished tamoxifen benefit

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sanne Løkkegaard ◽  
Daniel Elias ◽  
Carla L. Alves ◽  
Martin V. Bennetzen ◽  
Anne-Vibeke Lænkholm ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Cancer Patients ◽  
Endocrine Therapy ◽  
Endocrine Resistance ◽  
Predictive Marker ◽  
Endocrine Treatment ◽  
Breast Cancer Patients ◽  
Minichromosome Maintenance ◽  
Primary Tumors

AbstractResistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer is a major clinical problem with poorly understood mechanisms. There is an unmet need for prognostic and predictive biomarkers to allow appropriate therapeutic targeting. We evaluated the mechanism by which minichromosome maintenance protein 3 (MCM3) influences endocrine resistance and its predictive/prognostic potential in ER+ breast cancer. We discovered that ER+ breast cancer cells survive tamoxifen and letrozole treatments through upregulation of minichromosome maintenance proteins (MCMs), including MCM3, which are key molecules in the cell cycle and DNA replication. Lowering MCM3 expression in endocrine-resistant cells restored drug sensitivity and altered phosphorylation of cell cycle regulators, including p53(Ser315,33), CHK1(Ser317), and cdc25b(Ser323), suggesting that the interaction of MCM3 with cell cycle proteins is an important mechanism of overcoming replicative stress and anti-proliferative effects of endocrine treatments. Interestingly, the MCM3 levels did not affect the efficacy of growth inhibitory by CDK4/6 inhibitors. Evaluation of MCM3 levels in primary tumors from four independent cohorts of breast cancer patients receiving adjuvant tamoxifen mono-therapy or no adjuvant treatment, including the Stockholm tamoxifen (STO-3) trial, showed MCM3 to be an independent prognostic marker adding information beyond Ki67. In addition, MCM3 was shown to be a predictive marker of response to endocrine treatment. Our study reveals a coordinated signaling network centered around MCM3 that limits response to endocrine therapy in ER+ breast cancer and identifies MCM3 as a clinically useful prognostic and predictive biomarker that allows personalized treatment of ER+ breast cancer patients.

scholarly journals Circulating tumor DNA dynamics in advanced breast cancer treated with CDK4/6 inhibition and endocrine therapy

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Olga Martínez-Sáez ◽  
Tomás Pascual ◽  
Fara Brasó-Maristany ◽  
Nuria Chic ◽  
Blanca González-Farré ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Advanced Breast Cancer ◽  
Endocrine Therapy ◽  
Methodological Approach ◽  
Progression Free Survival ◽  
Circulating Tumor Dna ◽  
Advanced Breast ◽  
Dna Dynamics ◽  
Ca 15.3 ◽  
Tumor Dna

AbstractCirculating tumor DNA (ctDNA) levels may predict response to anticancer drugs, including CDK4/6 inhibitors and endocrine therapy combinations (CDK4/6i+ET); however, critical questions remain unanswered such as which assay or statistical method to use. Here, we obtained paired plasma samples at baseline and week 4 in 45 consecutive patients with advanced breast cancer treated with CDK4/6i+ET. ctDNA was detected in 96% of cases using the 74-gene Guardant360 assay. A variant allele fraction ratio (VAFR) was calculated for each of the 79 detected mutations between both timepoints. Mean of all VAFRs (mVAFR) was computed for each patient. In our dataset, mVAFR was significantly associated with progression-free survival (PFS). Baseline VAF, on-treatment VAF or absolute changes in VAF were not associated with PFS, nor were CA-15.3 levels at baseline, week 4 or the CA-15.3 ratio. These findings demonstrate that ctDNA dynamics using a standardized multi-gene panel and a unique methodological approach predicts treatment outcome. Clinical trials in patients with an unfavorable ctDNA response are needed.

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