BIOM-14. SYSTEMIC BIOMARKERS OF TUMOR BURDEN IN GLIOBLASTOMA PATIENTS

Glioblastomas (GBM) are Grade IV gliomas that are highly aggressive, lethal primary brain tumors. They are extremely heterogenous tumors both at a cellular and molecular level, harboring diverse oncogenes and mutated tumor suppressor genes with both inter- and intra-tumor variability in expression patterns. Currently, the presence of GBM cannot be predicted and they are diagnosed post-surgical resection by histologic evaluation of tumor tissue. There is an urgent, unmet need for the discovery of GBM-specific biomarkers that could precisely predict and monitor the presence of tumors in GBM patients. Over the last seven years we have carried out a prospective, multi-center, clinical study to longitudinally analyze tumor and plasma samples from GBM patients. We have characterized expression levels of microRNAs, mRNAs and proteins isolated from plasma samples collected from GBM patients throughout their treatment and compared these data to clinical and pathological reports for each patient. Our research has identified a set of systemic microRNAs and their targets that can be correlated to tumor burden in GBM patients. Data will be presented to demonstrate how specific sets of molecular markers and secreted proteins can track disease in GBM patients. This study provides insights into how systemically expressed biomarkers in GBM patients can be used in the development of methods for the precise assessment of disease progression and treatment efficacy while being minimally invasive and cost-effective. Combining clinicopathological findings and biomarker profiling will predict treatment outcomes and provide oncologists precise readouts for tumor burden and response to treatment. Furthermore, this research will also provide critically needed criteria for rigorous monitoring of efficacy of all new therapeutic trials for GBM.