What Is a Liquid Biopsy?
A liquid biopsy is a non-surgical screening approach: tumor-derived signals in the blood (such as cfDNA methylation patterns) are analyzed.
A liquid biopsy is a screening approach that does not require a surgical tissue sample. Tumors shed cell-free DNA (cfDNA) and other biomarkers into the bloodstream even at the earliest stages; liquid biopsy tests look for those signals.
How It Works
Galleri® analyzes methylation patterns on cfDNA in blood using next-generation sequencing and machine learning. Methylation signatures allow the test to predict not only the presence of a signal but also the anatomic region it originates from (Cancer Signal Origin — CSO).
Difference From Standard Screenings
- A single blood draw screens for signals across more than 50 cancer types — standard screenings focus on a single cancer.
- Many cancer types have no standard screening today; Galleri aims to complement that gap.
Important Limitations
- Galleri® is a screening test; it is not a diagnostic test.
- A negative result does not definitively rule out cancer.
- A positive result is not a diagnosis; it requires diagnostic work-up.
- It does not replace your routine screenings (mammography, colonoscopy, etc.).