Now imagine you could see these mutations—see cancer itself—in a vial of blood. Nearly every type of cancer sheds DNA into the bloodstream, and Vogelstein’s laboratory at Johns Hopkins has developed a technique, called a “liquid biopsy,” that can find the telltale genetic material.
The technology is made possible by instruments that speedily sequence DNA in a blood sample so researchers can spot tumor DNA even when it’s present in trace amounts. The Hopkins scientists, working alongside doctors who treat patients in Baltimore’s largest oncology center, have now studied blood from more than a thousand people. They say liquid biopsies can find cancer long before symptoms of the disease arise.
For the first time, Hopkins researchers say, they are within reach of a general screening tool that could be used to scan broadly—perhaps at an annual physical—for molecular traces of cancer in people with no symptoms.