Blood test offers another way to diagnose cancer

Scientists in the United Kingdom have designed an inexpensive blood test that can detect cancer with a high degree of accuracy in people with non-specific symptoms, such as fatigue and weight loss.

Developers from the University of Oxford say the test, which involves an emerging form of cancer detection, could be ordered by primary care doctors, and has the potential to expedite the diagnosis process.

In a study published in the journal Clinical Cancer Research, the Oxford researchers analyzed samples from 300 patients with non-specific but concerning symptoms of cancer, including fatigue and rapid weight loss, and assessed whether the test could distinguish patients with a range of solid tumors from those without cancer.

The test was accurate in 19 out of every 20 patients with cancer, and also successfully identified if the cancer had metastasized, or spread, with 94 percent accuracy.

Fay Propert, a biochemist at the University of Oxford who led the research, said that, once validated, the test will allow "accurate, timely, and cost-effective" triaging of patients with suspected cancer.

"The goal is to produce a test for cancer that any GP (general practitioner) can request," said Propert. "This work describes a new way of identifying cancer."

Many currently available blood-based cancer tests work by detecting genetic material from tumors that might be present in the blood. The test from the Oxford scientists looks instead for chemicals known as metabolites that are produced by tumors and that serve as biomarkers for cancer.

The hypothesis that cancer cell metabolism is distinct from that of normal cells was first raised by German Nobel Laureate Otto Warburg in the 1920s, though scientists are only now starting to understand how metabolites produced by tumors can be used as biomarkers to accurately detect cancer.

The test involves a technique called nuclear magnetic resonance, or NMR, metabolomics, which uses magnetic fields and radio waves to profile metabolites in blood and other fluids, including urine.

Early forms of the technology were established more than 40 years ago, though its potential in cancer diagnostics is yet to be fully realized, with studies only beginning in earnest within the last decade.

James Larkin, a University of Oxford oncologist who worked on the new study, said NMR metabolomics can accurately detect the presence of cancer cells because scientists now have a handle on their "unique metabolomic fingerprints".

Larkin has previously performed research into tracking the progress of multiple sclerosis using NMR metabolomics, and said the technology can successfully identify when the degenerative disease is approaching its latter stages, even before trained clinicians can tell.

"It is very exciting that the same technology is now showing promise in other diseases, like cancer," he said.

The next step will be to assess the accuracy of the test in a larger study involving thousands of individuals, after which it may be validated by regulatory agencies for clinical use.