Guardant360® CDx
Liquid Biopsy
Genomic Profiling from Circulating Tumor DNA
Guardant360 CDx isn't a tissue test.
It's a liquid biopsy.
Guardant Health's Guardant360 CDx analyzes circulating tumor DNA (ctDNA) from blood using NGS-based comprehensive genomic profiling (CGP). Instead of sequencing tumor tissue, it measures tumor-derived DNA fragments circulating in the bloodstream.
What the Test Measures
Circulating Tumor DNA (ctDNA)
- Tumor-derived DNA fragments isolated from blood
- Enables genomic profiling without requiring tissue biopsy
- Reflects real-time tumor biology across metastatic sites
DNA Alterations
- 74 cancer genes evaluated
- Detects single nucleotide variants (SNVs), insertions/deletions (indels), and copy number alterations
- Includes key oncogenic drivers relevant for targeted therapy
RNA Fusion Rearrangements
- Detection of clinically relevant gene fusions
- Covers key oncogenic drivers across multiple tumor types
Genomic Signatures
- MSI (Microsatellite Instability)
Why This Matters
These biomarkers support FDA-approved therapy–biomarker associations across oncology, enabling treatment selection when tissue is limited or unavailable.
In practice, tumor tissue is often inaccessible, insufficient, or impractical to obtain. Liquid biopsy provides a clinically viable alternative—allowing genomic profiling from a simple blood draw.
How Casandra Structures This
At Casandra.ai, we separate what a test measures from what it reports—capturing both the biological source of the sample and the structure of the assay.
Some genomic tests analyze tissue. Others analyze blood. Some sequence broadly across the genome, while others focus on targeted regions.
Understanding these differences is essential to selecting the right test and interpreting results appropriately.