Next Gen Dx Summit
August 23-26, 2016
Circulating Tumor Cell Program:
Wed., August 24th at 12:50pm (Lunch Provided)
Sensitive Assays to Detect Mutant ESR1 in Plasma Circulating Tumor DNA from Breast Cancer Patient Samples
Gaorav Gupta, M.D., Ph.D.
Assistant Professor, Division of Radiation Oncology
UNC-Chapel Hill School of Medicine
Digital PCR Symposia: Fri., August 26th at 9:30am
Mutant DNA Quantification by Digital PCR Can Be Confounded by Heating During DNA Fragmentation
Qing Kang, Ph.D.
Research Fellow, Internal Medicine
University of Michigan
Digital PCR Symposia: Fri., August 26th at 11:30am
Using Picodroplet Digital PCR Technology on NGS Libraries to Create Rapid, Highly Sensitive Assays for Mutation Detection
Maria Arcila, Ph.D.
Director, Diagnostic Molecular Pathology Laboratory,
Associate Attending Pathologist
Memorial Sloan Kettering Cancer Center
Attend Our Lunch Workshop
Date/Time: Wednesday, August 24, 2016 at 12:50pm
Speaker: Gaorav Gupta, M.D., Ph.D., Assistant Professor in the Division of Radiation Oncology at UNC-Chapel Hill School of Medicine
Title: Sensitive assays to detect mutant ESR1 in plasma circulating tumor DNA from breast cancer patient samples
Abstract: Mutant estrogen receptor (ESR1) has emerged as a clinically significant mechanism for acquired resistance to endocrine therapy in metastatic breast cancer (MBC). ESR1 mutations are rarely identified in untreated primary breast cancers, but are present in up to 30% of patients with estrogen receptor positive (ER+) MBC who have progressed on multiple prior lines of endocrine therapy. Several of the most commonly identified mutations cluster in the ligand-binding domain of ESR1 – including D538G and Y537S/N/C – and have been postulated to confer endocrine therapy resistance due to ligand-independent activation and/or reduced affinity for estrogen receptor antagonists. Reports have also described additional ESR1 mutations in other parts of the gene that are less prevalent but may also have a clinically significant role in mediating therapeutic resistance. Here, we describe a multiplexed digital PCR ESR1 assay to perform absolute quantification of variant alleles in ctDNA from a cohort of patient samples with MBC. We demonstrate the ability to detect changes in allelic burden with longitudinal sampling from the same individual. We also report the development and validation of a custom ThunderBolts Open Source assay on the RainDrop platform to screen for additional mutations in the entire ESR1 coding region. Highly sensitive, specific, and accurate assays to detect mutant ESR1 alleles in plasma ctDNA – such as the assays described here – could contribute to the optimal and personalized management of patients with ER+ MBC.
Biography: Dr. Gupta is a physician-scientist at the University of North Carolina at Chapel Hill. He obtained his MD and PhD degrees from the Weill Medical College of Cornell University, and completed his postgraduate training at Memorial Sloan Kettering Cancer Center. His laboratory studies DNA repair and mutagenesis pathways in breast cancer pathogenesis. His prior research made important contributions to our understanding of breast cancer metastasis. More recently, his laboratory has been developing tools to monitor mutagenic processes that drive breast cancer progression and treatment resistance. Dr. Gupta is also a practicing radiation oncologist at the UNC North Carolina Cancer Hospital, specializing in the care of breast cancer patients.