New blood test detects 8 types of cancer with 70% accuracy

The cancer, even before the first symptoms, begins to leave traces in the blood. They may be small pieces of mutant DNA, floating between red and white blood cells. They may also be proteins with a peculiar amino acid sequence, which could only have been made by the cells of a tumor.

Each type of cancer - there are more than a hundred of them - leaves a different trail of substances, a unique set of footprints in your body. It's like when two people, one in slippers and one in cotton, step on the cool cement of the sidewalk. We are now on track to identify these footprints with a needle - still in the first stages of the tumor, when the damage is not as great and the treatment almost always works.

That is the promise of a new type of blood test, announced yesterday in Science . When applied to 1005 volunteers with diagnosed cancer, they identified the disease and organ reached in 70% of the cases - the success rate varied between 39% and 96% according to the type. All with a little bottle of the liquid, no x-ray or magnetic resonance imaging. Among the types tested are some of the most common: breast , lung, ovary, liver, stomach, pancreas, esophagus and rectum. The method was also tested on 812 people who were not sick, to check the number of false alarms. There were only seven mistakes.