Cancer survival rates dramatically increase when the disease is caught early, but there has not been an effective, non-invasive test that will detect most types of cancer early.

Now, an international team of researchers has developed a blood test that can diagnose certain cancers years before symptoms occur.

“What we showed is: up to four years before these people walk into the hospital, there are already signatures in their blood that show they have cancer,” study coauthor and University of California bioengineer Kun Zhang told Scientific American. “That’s never been done before.”

The test is part of a larger effort to create a “liquid biopsy” for early cancer detection, The Guardian explained. While other studies have reported positive results for blood tests that detect cancer relatively early, few can detect it before any symptoms develop.

But the new test, called PanSeer, detected cancer in 95 percent of asymptomatic patients who went on to receive a diagnosis.

The study, published in Nature Communications Tuesday, is also unique because of how the test was developed, Scientific American […]