Abstract PO3-20-07: Five years and counting: A case of a 47-year-old female with De Novo Metastatic HER2 positive disease on multiple lines of treatment

Abstract HER2-positive breast cancer refers to a specific subtype of breast cancer characterized by the overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) protein on the surface of cancer cells. The overexpression of HER2 leads to increased signaling pathways that promote cell growth and division, making HER2-positive breast cancer inherently more aggressive compared to other subtypes. The aggressive behaviour of HER2-positive disease may be attributed to its rapid cell growth, high metastatic potential, and increased risk of recurrence. Fortunately, there are targeted therapies that specifically inhibit the HER2 protein. These targeted treatments help to block HER2 signaling, slow down tumor growth, and reduce the risk of recurrence. We report a case 47 year old premenoapausal Filipino female diagnosed with de-novo metastatic HER2-positive breast cancer with liver and lung metastasis in 2018. Advised Pertuzumab Trastuzumab and Taxane therapy but due to financial constraints was amenable only to Trastuzumab and Paclitaxel. During treatment noted symptomatic cardiac decline, hence shifted to Lapatinib 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-20-07.