Abstract 5703: An ultra-sensitive multiplex allele-specific real-time PCR (Udx-PCR) assay for detection of ESR1 mutations in metastatic breast cancer

Abstract

Abstract Activating mutations of estrogen receptor α (ESR1) are attributed to acquired resistance to estrogen-deprivation therapy in patients with metastatic breast cancer (MBC). Thus, detection of these mutations is clinically critical for monitoring early progression and effective therapeutic options in treatment of BC patients under hormonal therapy. However, current investigations for detection ESR1 mutations mainly focus on digital PCR technology due to low abundance of the cfDNA in plasma samples, which is not a currently feasible method for clinical diagnosis. Herein, we developed a multiplex allele-specific real-time (ARMS) PCR assay for detection of ESR1 four mutations (Y537S, Y537C, Y537N, and D538G) in a single tube reaction. In this real-time PCR system, the wild-type ESR1 DNA is completely blocked by a modified probe with a higher annealing temperature, and the mutant gene is selectively amplified by the modified ARMS primers. The assay was found to be highly specific and sensitive. With this assay, as low as 0.1% mutant DNA template in the background of a total of 10ng wild-type genomic DNA could be detected. By using this assay, we analyzed the ESR1 mutations in 50 Chinese MBC FFPE and plasma samples. The ESR1 mutations were detected in 3 FFPE and 6 plasma samples, which were confirmed by pyrophosphate sequencing. The multiplex allele-specific real-time PCR assay provides a rapid and reliable diagnostic tool for accurate detection of ESR1 mutations with potential for clinical application. Citation Format: Jiasu Liu, Yaohuai Wang, Shengrong Sun, Dehua Derek Yu. An ultra-sensitive multiplex allele-specific real-time PCR (Udx-PCR) assay for detection of ESR1 mutations in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5703. doi:10.1158/1538-7445.AM2017-5703