Illustrative photo. (Internet)

The Galleri test looks at the DNA in a patient's blood to determine if any come from cancer cells.

Earlier diagnosis of cancers leads to dramatically increased survival rates.

Peter Sasieni, professor of cancer prevention at King's College London said they need to study the Galleri test carefully to find out whether it can significantly reduce the number of cancers diagnosed at a late stage.

The test could be a game changer for early cancer detection, he noted.