Fig. 1

Study overview. A shows the workflow of patient data and tissue collection to the evaluation with different technologies, i.e., RNA sequencing (yellow), immunohistochemistry (orange) and multiplex immunofluorescence (red). The different platforms provided signatures expression data (yellow), quantitative cell data (lavender) and cell-to-cell spatial composition data (purple). For 97 patients, signature expression data was available, this included 91 primary tumor samples and 21 metastasis samples. For 15 patients a sample of the primary tumor and of a metastasis was available. For 123 patients quantitative cell data was available, this included 110 primary tumor samples and 39 metastasis samples. For 26 patients a sample of the primary tumor and of a metastasis was available. For 103 patients cell-to-cell spatial composition data was available, this included 99 primary tumor samples and 19 metastasis samples. For 15 patients a sample of the primary tumor and of a metastasis was available. We evaluated associations with OS and rCR as well as differences between primary tumors and metastases. This led to thorough overview of tumor molecular and immune micro-environmental features correlated with HER2-positive MBC patients’ outcomes. B is an overview of sample sites. The number of samples is indicated. Credit: Created with BioRender (https://biorender.com/)