Cancer
Liquid Biopsy: Detecting Cancer from a Blood Draw
A new liquid biopsy test can identify markers for over 50 types of cancer from a single blood sample, enabling earlier detection and dramatically improving survival odds.
What Is a Liquid Biopsy?
A liquid biopsy analyzes cell-free DNA (cfDNA) fragments shed by tumors into the bloodstream. These fragments carry methylation patterns and mutations unique to cancer cells, allowing the test to detect cancer presence and even identify the tissue of origin from a routine blood draw.
The Galleri Test and Beyond
Grail's Galleri test, currently available by prescription, screens for over 50 cancer types with a signal origin identified in more than 88% of positive results. Large-scale NHS trials in the UK are enrolling 140,000 participants to validate its population-level screening potential.
Equity Implications
Liquid biopsies could revolutionize cancer screening in communities where colonoscopies, mammograms, or other invasive procedures face uptake barriers due to cost, transportation, or cultural hesitation. A single blood draw at a community clinic could become a gateway to life-saving early detection.
