Molecular Tumor Board: 58-year-old woman with ESR1 altered hormone receptor positive breast cancer

In this Molecular Tumor Board, our Medical Affairs team discussed a case of metastatic hormone-receptor positive breast cancer with acquired resistance to endocrine therapy, where ESR1 alterations were identified. The team reviewed the distinction and clinical actionability between ESR1 mutations and ESR1 fusions in breast cancer. Lastly, they explored the respective roles of tissue and liquid biopsy in detecting these alterations, including practical considerations and limitations of using tissue biopsy to identify ESR1 alterations.