News Health & Medicine

Cancer DNA is detectable in blood years before diagnosis

Blood samples taken from people more than three years before a diagnosis show tumor traces

This microscopy image shows a breast cancer cell dividing into two. The components of the cell are shown in bright green, blue and red.

Cancer cells, like these dividing breast cancer cells, can shed DNA fragments into the bloodstream. Tests to spot these fragments could aid early cancer detection efforts.

Wei Qian/Univ of Pittsburgh, NCI

By Meghan Rosen

Cancer’s genetic fingerprints may lurk in people’s blood long before they find out about the disease.