198P Cerebrospinal fluid immune cell profiling in patients with metastatic breast cancer and leptomeningeal disease

One of the most devastating complications of metastatic breast cancer (MBC) is the development leptomeningeal disease (LMD), which has a median overall survival of 2-4 months. In order to develop better diagnostic and therapeutic tools for LMD, it is important to better understand the biology of this condition. The objective of this project is to characterize the cerebrospinal fluid (CSF) immune microenvironment at the proteomic level, with a focus on better understanding the exhaustion state of T cells in patients with MBC and LMD.