Abstract P6-16-08: The impact of genomic mutation on metastatic breast cancer treatment: A retrospective clinical trial

Background: Next-Generation Sequencing (NGS) has made genomic mutation-driven cancer medicine feasible. Recognizing the importance of pathway and biomarker-driven personalized therapy for patients with metastatic breast cancer (MBC), we frequently submit tumor tissue for FoundationOne® genomic sequencing. Here we report the results and clinical impact of this test in 44 patients with MBC. Patients and Methods: An institution IRB protocol was established for this retrospective clinical trial performed at the City of Hope Comprehensive Cancer Center from January 2014 to May 2016 with available tumor genomic DNA mutation results through FoundationOne® testing. Patients9 clinical characteristics including age, race, treatment history, clinical outcome and genomic mutation profiles were reviewed. Results: We identified 44 patients with MBC submitted for FoundationOne® genomic profiling: 24 triple negative breast cancer (TNBC), 16 estrogen receptor positive (ER + ) and 4 human epidermal growth factor receptor 2 positive (HER2 + ). A total of 23 patients received over 3 lines of chemotherapies prior to FoundationOne® testing. Actionable mutations were identified in 42 of the 44 patients and 23 patients (52%) initiated mutation-driven targeted therapies. Of these 23 patients treated, a total of 17 had accessible responses and 6 patients did not have accessible responses due to short exposure ( Conclusion: Targeted genomic sequencing through FoundationOne® can identify effective therapy that has not generally been used based on pathology type. NGS should be performed early in patients with good performance status. This approach should be utilized in a setting where genomic mutation driven therapeutic trials are available. Contact information: Yuan Yuan MD PhD, Department of Medical Oncology & Molecular Therapeutics; City of Hope Comprehensive Cancer Center; Duarte, CA 91030; Email: yuyuan@coh.org. Citation Format: Yuan Y, Yost S, Yuan Y-C, Liu Z, Frankel P, Nicola S, Mortimer J. The impact of genomic mutation on metastatic breast cancer treatment: A retrospective clinical trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-16-08.