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

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.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13045-e13045
Author(s):  
Jesús Fuentes Antrás ◽  
Vanesa García-Barberán ◽  
Irene Gonzalo ◽  
Fernando Moreno ◽  
Igor López-Cade ◽  
...  

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.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Olga Martínez-Sáez ◽  
Tomás Pascual ◽  
Fara Brasó-Maristany ◽  
Nuria Chic ◽  
Blanca González-Farré ◽  
...  

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.


2016 ◽  
Vol 34 (25) ◽  
pp. 2961-2968 ◽  
Author(s):  
Charlotte Fribbens ◽  
Ben O’Leary ◽  
Lucy Kilburn ◽  
Sarah Hrebien ◽  
Isaac Garcia-Murillas ◽  
...  

Purpose ESR1 mutations are selected by prior aromatase inhibitor (AI) therapy in advanced breast cancer. We assessed the impact of ESR1 mutations on sensitivity to standard therapies in two phase III randomized trials that represent the development of the current standard therapy for estrogen receptor–positive advanced breast cancer. Materials and Methods In a prospective-retrospective analysis, we assessed ESR1 mutations in available archived baseline plasma from the SoFEA (Study of Faslodex Versus Exemestane With or Without Arimidex) trial, which compared exemestane with fulvestrant-containing regimens in patients with prior sensitivity to nonsteroidal AI and in baseline plasma from the PALOMA3 (Palbociclib Combined With Fulvestrant in Hormone Receptor–Positive HER2-Negative Metastatic Breast Cancer After Endocrine Failure) trial, which compared fulvestrant plus placebo with fulvestrant plus palbociclib in patients with progression after receiving prior endocrine therapy. ESR1 mutations were analyzed by multiplex digital polymerase chain reaction. Results In SoFEA, ESR1 mutations were found in 39.1% of patients (63 of 161), of whom 49.1% (27 of 55) were polyclonal, with rates of mutation detection unaffected by delays in processing of archival plasma. Patients with ESR1 mutations had improved progression-free survival (PFS) after taking fulvestrant (n = 45) compared with exemestane (n = 18; hazard ratio [HR], 0.52; 95% CI, 0.30 to 0.92; P = .02), whereas patients with wild-type ESR1 had similar PFS after receiving either treatment (HR, 1.07; 95% CI, 0.68 to 1.67; P = .77). In PALOMA3, ESR1 mutations were found in the plasma of 25.3% of patients (91 of 360), of whom 28.6% (26 of 91) were polyclonal, with mutations associated with acquired resistance to prior AI. Fulvestrant plus palbociclib improved PFS compared with fulvestrant plus placebo in both ESR1 mutant (HR, 0.43; 95% CI, 0.25 to 0.74; P = .002) and ESR1 wild-type patients (HR, 0.49; 95% CI, 0.35 to 0.70; P < .001). Conclusion ESR1 mutation analysis in plasma after progression after prior AI therapy may help direct choice of further endocrine-based therapy. Additional confirmatory studies are required.


Oncology ◽  
1994 ◽  
Vol 51 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Derek J. Crawford ◽  
David George ◽  
David C. Smith ◽  
Moira Stewart ◽  
James Paul ◽  
...  

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13017-e13017
Author(s):  
Inês Moreira ◽  
Marta Ferreira ◽  
Ana Afonso ◽  
Ana Ferreira ◽  
Ana Rodrigues ◽  
...  

e13017 Background: Activation of the mammalian target of rapamycin intracellular signaling pathway is one of the mechanisms of endocrine resistance in breast cancer. The addition of everolimus to exemestane improves progression-free survival (PFS) in patients with hormone receptor positive (HR+) advanced breast cancer (ABC) previously treated with nonsteroidal aromatase inhibitors (NSAIs). The aim of this study was to assess the effectiveness and safety of everolimus plus exemestane in patients with HR+ ABC. Methods: We retrospectively evaluated patients with HR+, HER2 negative ABC treated with everolimus/exemestane that recurred or progressed during/after treatment with NSAIs in a portuguese comprehensive cancer center. Study endpoints were PFS, overall survival (OS), overall response rate and adverse events. Results: Between April 2014 and September 2020, 63 female patients were treated with everolimus/exemestane. Median age was 59 years (36-79), and all had performance status ECOG ≤2. Seventeen (27.0%) patients had bone metastasis alone, 39 (61.9%) had bone and visceral metastasis, 25 (39.7%) had metastasis in 3 or more sites and 87.3% had previous hormone-sensitive disease. Before everolimus/exemestane, 61 (96.8%) patients were being treated with palliative endocrine therapy (alone or in combination with CDK4/6 inhibitors) or chemotherapy (ChT) and 2 (3.2%) patients were under adjuvant endocrine therapy. Median follow-up time was 12.8 months (1.4-74.6), with 39 patients alive. Overall response rate was 14.3% (1 complete response and 8 partial responses) and 45 patients had stable disease. Median PFS was 5.6 months (CI95% 2.4-8.8) and median OS was 25.4 months (CI95% 10.3-40.5). Subgroup analysis regarding PFS was statistically significant for previous treatment with CDK4/6 inhibitors (p = 0.026) and for site of metastasis (p = 0.025). In the subgroup of patients that previously underwent palliative ChT, median PFS was 4.0 months (CI95% 0.2-9.6) and median OS was 18.6 months (CI95% 8.2-29.0). For patients that did not receive previous palliative ChT, median PFS was 5.8 months (CI95% 3.8-7.8) and median OS was 43.5 months (CI95% 2.0-85.0). Grade 3 and 4 adverse events occurred in 21 (33.3%) patients, and were: nausea, anorexia, rash, headache, haematologic toxicity, hepatic cytolysis, hyperglycaemia, pneumonitis, oral mucositis and acute kidney failure with need for haemodialysis. Fifty-five (87.3%) patients suspended everolimus, 34 (54.0%) due to disease progression and 21 (33.3%) due to toxicity. Conclusions: Our results confirm the effectiveness and safety of everolimus/exemestane in real-world setting and support its use mainly before palliative ChT. Everolimus/exemestane in HR+ ABC is feasible in the clinic, with toxicity manageable under close surveillance.


Author(s):  
Jennifer K. Litton ◽  
Harold J. Burstein ◽  
Nicholas C. Turner

Molecular testing for genetic and genomic variation has become an integral part of breast cancer management. Patients with a family history of breast cancer or other tumors, bilateral breast cancers, or early-onset breast cancers warrant genetic testing to determine whether a hereditary cancer syndrome is present. The availability of PARP inhibitors—drugs that are selectively active in BRCA1/2-associated breast cancers—has created the need for hereditary cancer testing for all patients diagnosed with advanced breast cancer. Tumor genomic profiling is the standard of care for many types of malignancies and is becoming increasingly important in the management of advanced breast cancer. Targetable mutations in advanced breast cancer include PIK3CA, HER2, and rare instances of mismatch deficiency or other targets for tyrosine kinase inhibitors. The development of methods for sequencing cell-free DNA should allow for broader and easier implementation of tumor genomic testing. Transcriptome-based expression signatures have become the standard of care in the management of early-stage estrogen receptor–positive breast cancers. These assays provide prognostic significance in the setting of adjuvant endocrine therapy and are predictive for benefit from adjuvant chemotherapy. Collectively, these developments underscore the contemporary reality that molecular testing is now part of the clinical management for the majority of patients with breast cancer.


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