Guardant Reveal finds evidence of remaining cancer by looking for circulating tumor DNA or “ctDNA” in a blood sample.
Everyone has pieces of DNA floating in their blood. Most of that DNA comes from normal cells. However, individuals with cancer also have low levels of DNA from their tumor called circulating tumor DNA (ctDNA) in their blood.
Guardant Reveal identifies DNA fragments that come from colorectal tumors by testing the DNA for mutations known to be associated with colorectal cancer, as well as specific methylation patterns that are unique to colorectal cancers. This integration of both genomic and methylation signals allows for improved sensitivity (ability to detect more patients with remaining cancer) of the assay over just looking at DNA mutations alone.
Guardant Reveal is the first ctDNA test for minimal residual disease (MRD) and recurrence monitoring that does not require tumor tissue. A blood-only liquid biopsy allows for easier ordering and faster time to results.
Guardant’s Medical Science Liaison, Leslie Bucheit, discusses Reveal in more detail in this conversation with PALTOWN’s Scientific Director, Dr. Manju George: