A simple blood test may detect cancer earlier than ever. Liquid biopsies read fragments of tumor DNA circulating in the blood. Multi-cancer early-detection tests moved into large studies this decade.
DNA in the blood
The signal is faint. Dying tumor cells shed DNA into circulation. Sensitive assays find it.
Many cancers at once
Breadth is the aim. One test screens for signals from many tumor types. Coverage is wide.
Early detection
Timing is everything. Catching cancer early improves survival. The promise is large.
False positives
Caution is due. Overdiagnosis and false alarms are real risks. Balance is delicate.
Large trials
Evidence is building. Studies enroll hundreds of thousands. Rigor is essential.
Toward the clinic
Adoption looms. Regulators are weighing the tests. The path is opening.
The bottom line
Liquid biopsies detect circulating tumor DNA to screen for many cancers in a blood draw. Early detection could save lives, but false positives are a concern. Large trials are testing the approach.
