Blood test reveals surprising results in detecting 50 types of cancer

A blood test that can detect more than 50 types of cancer has been published in a North American study.

The study showed that the test was able to detect various types of cancer, of which almost three-quarters do not have a regular screening program. More importantly, more than half of the cancers detected were at an early stage - where treatment is easier and the chances of a cure are higher. 

This blood test, known as the Gallery Test, was developed by the US pharmaceutical company Grail. It can detect small pieces of cancerous DNA, which are detached from tumors and float in the blood. The test is currently being run as a trial by the UK's NHS.

The study monitored 25,000 adults in the US and Canada for a year. About 1 percent of them tested positive and 62 percent of these cases were later confirmed to have cancer.

“This blood test could revolutionize the way we screen for cancer,” said lead author Dr. Nima Nabavizadeh, an associate professor in the Department of Radiation Medicine at Oregon Health & Science University.

Oregon added, “This technology could detect many types of cancer early, when treatment is most likely to be successful.”

The study also found that the test correctly ruled out cancer in 99 percent of cases in those whose tests did not show cancer.

Combining the blood test with breast, bowel and cervical screening would increase cancer detection rates sevenfold.

Most notably, three-quarters of the cancers detected were types for which there is no screening program; such as ovarian, liver, stomach, bladder and pancreatic cancers.

The test was also able to correctly determine the source of the cancer in 90 percent of cases.

Experts not directly involved in the study say more time and data are needed to prove whether the test can reduce cancer deaths.

Professor Claire Turnbull, of the Institute of Cancer Research in London, said: “Unless we have data on mortality from randomised trials, it is not possible to confirm the true effectiveness of the test.”

A summary of the study will be presented at the European Society for Medical Oncology Congress in Berlin on Saturday (October 18), although the full report has not yet been published in a peer-reviewed journal.

The next major trial is a three-year NHS trial in England involving 140,000 people. Results will be published next year. If successful, the NHS has said it will be rolled out to a further 1 million people.

Sir Harpal Kumar, president of Grail's biopharma division, said: "The results are very promising."

Harpal told the BBC: "This technology is allowing us to detect many more aggressive types of cancer at an early stage - when treatment is more effective and curable."

However, Nasser Turabi, of Cancer Research UK, warned: "More research is needed to avoid overdiagnosis - because some cancers may never have caused any real harm."

Turabi added: "The UK's National Screening Committee will play a key role in deciding whether these tests will be accepted by the NHS."