New cancer blood test breakthrough
Scientists from Johns Hopkins University have taken a step towards one of the biggest goals in medicine, a universal blood test for cancer. The researchers have trialled a method that can detect up to eight common forms of the disease.
The scientists envision the research to be developed into an annual test designed to catch cancer early and save lives.
However, further research is required to assess the test’s effectiveness at detecting early-stage cancers.
Tumours release tiny traces of their mutated DNA and proteins they make into the bloodstream. The CancerSEEK test uses this to look for mutations in 16 genes that regularly arise in cancer and eight proteins that are often released.
The test was first trialled on 1,005 patients with cancers in the ovary, liver, stomach, pancreas, oesophagus, colon, lung or breast that had not yet spread to other tissues and overall, the test found 70% of the cancers.
Dr Cristian Tomasetti, from Johns Hopkins University School of Medicine, told the BBC: “This field of early detection is critical. I think this can have an enormous impact on cancer mortality.”
Five of the eight cancers investigated have no screening programmes for early detection. In some cases, the test also provided information about the tissue-of-origin of the cancer – but not all.
Pancreatic cancer has so few symptoms and is detected so late that four in five patients die in the year they are diagnosed.
Finding tumours when they could still be surgically removed would be “a night and day difference” for survival, said Dr Tomasetti.
CancerSEEK is now being trialled in people who have not been diagnosed with cancer, which will be the real test of its potential. The hope is it can complement other screening tools such as mammograms for breast cancer and colonoscopies for colorectal cancer.
Dr Gert Attard, team leader in the Centre for Evolution and Cancer at the Institute of Cancer Research, London, and consultant medical oncologist at the Royal Marsden NHS Foundation Trust, told the BBC: “This is of massive potential. I’m enormously excited. This is the Holy Grail – a blood test to diagnose cancer without all the other procedures like scans or colonoscopy.”
He said “we’re very close” to using blood tests to screen for cancer as “we have the technology”.
But he cautioned there was still uncertainty about what to do when a cancer was diagnosed.
Paul Pharoah, professor of cancer epidemiology at the University of Cambridge, said more work was needed to assess how the test performs when cancers are less advanced.
He said: “Demonstrating that a test can detect advanced cancers does not mean that the test will be useful in detecting early stage symptomatic cancer, much less pre-symptomatic cancer. The sensitivity for the stage 1 cancers in the study was only 40%.”
The cost of CancerSEEK is less than $500 (£360) per patient, which is around the same price as a colonoscopy.
Source: BBC News