ESR1 Mutation Detection and Dynamics in Meningeal Carcinomatosis in Breast Cancer.

ESR1 Mutation Detection and Dynamics in Meningeal Carcinomatosis in Breast Cancer. J Breast Cancer. 2020 Apr;23(2):218-223 Authors: Carausu M, Melaabi S, Pierga JY, Bidard FC, Cabel L Abstract ESR1 mutation is frequently encountered in hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC), especially after aromatase inhibitor (AI) therapy, as a mechanism of resistance to endocrine therapy. Circulating tumor DNA-based detection of ESR1 mutation in plasma has been demonstrated as a prognostic and predictive factor for poor outcomes in subsequent AI therapy. In this case report, for the first time, we describe the detection of ESR1 mutation (p.Tyr537Ser) only in the cerebrospinal fluid (CSF) and not in the plasma of a patient with isolated leptomeningeal progression who was treated with AI for HR-positive, HER2-negative MBC (bone metastasis only). Circulating tumor DNA levels also appeared to be correlated with clinical evolution. We suggest that in the presence of isolated leptomeningeal metastasis and when tamoxifen or AI has been prescribed for HR-positive MBC, CSF should be screened for ESR1 mutations to potentially adjust systemic treatment. PMID: 32395380 [PubMed]
Source: Journal of Breast Cancer - Category: Cancer & Oncology Tags: J Breast Cancer Source Type: research