Abstract 4954: Clinical validation of a cell-free DNA liquid biopsy approach for noninvasive molecular profiling

Clinical molecular profiling of advanced cancers enables the identification of actionable genomic alterations to guide therapeutic decisions. Although profiling of tissue samples is considered the gold standard, specimens may be unavailable or unsuitable for testing due to limited tumor purity or specimen quality. Further, genetically informed treatment decisions are increasingly necessary after disease progression and re-biopsy in this setting may not be feasible. Circulating tumor DNA (ctDNA) approaches for identification of genetic alterations in cancer patients may be more informative as the alterations reflect the current status of the tumor. ctDNA is representative of multiple tumor sites within a patient and may aid in the detection of alterations throughout the course of therapy. However, the fraction of ctDNA obtained from a blood sample is often very low (