BSBM-04 the Multi-Omic Landscape of Somatic Variation Across a Pan-Cancer Cohort of Brain Metastases

Abstract INTRODUCTION Brain metastases pose a significant and growing challenge in clinical practice, yet the molecular variants of this tumor type has not previously been examined comprehensively across multiple cancer types. In particular, there has been limited focus on contrasting the genetic profiles of common brain metastases originating from primary sites like lung, breast, melanoma, colorectal, and renal cancers, with those arising infrequently such as prostate and others. METHODS We have prospectively collected over 125 fresh frozen brain metastases and matching germline reference samples from 14 different primary tumor types and to date have performed WGS, RNA-Seq and Epic 850k methylation profiling on 60 of these samples spanning both common and rare brain metastases. We have employed machine learning algorithms, network analysis techniques, and integrative bioinformatics pipelines to extract meaningful insights into the biological underpinnings of brain metastasis formation. RESULTS We conducted an in-depth investigation into the genomic, transcriptomic, and epigenomic profiles of brain metastases, spanning both common and rare types. By merging these diverse datasets, we identified distinct molecular modifications linked to brain metastases with low incidence rates compared to those more frequently observed. Notably, we observed heightened alterations in the regulation of Golgi dynamics, sensing of lipid species, chromatin remodeling factors, and cytoskeletal remodeling in rare brain metastases. These changes likely influence cell migration and invasion dynamics, elucidating the potential for unique characteristics of less common brain metastasis types. CONCLUSIONS This research indicates that the molecular mechanisms driving the formation of brain metastases may vary depending on whether the primary malignancy frequently or infrequently spreads to the brain. Studies such as these, will aid in eventually driving innovations in precision oncology and ultimately improving patient outcomes.