The new blood test for pancreatic cancer, described by the researchers behind it as ‘a major advance’, hunts for tiny spheres of fat that are shed by the cancers. Early results published in the journal Nature showed the test was 100% accurate. Experts said the findings are very significant but require refinement before they were ready for clinical use as a cancer test.

A wall of fat marks the boundary of every cell in the human body. Tiny spheres of fat – called vesicles or exosomes – can break away to store and transport goods around the body. The team at the Anderson Cancer Centre at the University of Texas looked for the unique signatures of cancer in these fatty exosomes. They noticed one protein, called proteoglycan glypican-1, was found in much higher levels in people with pancreatic cancer. Further tests on the blood of 270 people showed it was 100% accurate at distinguishing between cancers, other pancreatic disorders and healthy tissue.

One of the researchers, Dr Raghu Kalluri, told the BBC News website: “We think the ability to identify and isolate cancer exosomes is a major advance and provides the possibility of immensely benefiting our patients.”

He said the need for such a test was “huge” and it was “not too far” from the clinic.

“The clinical symptoms arise late in patients with this cancer and also the tools to track their disease before and after therapy and during remission and relapse are not good. So, having a reliable biomarker with the ability to identify mutations is of great value.”