What is cancer and how does it affect our body? Video / NZME
A blood test that can detect 10 types of cancer potentially years before someone becomes ill has been described as the "holy grail" of cancer research.
Scientists in the US have found a simple test can pick up early signs of cancers including breast, ovarian, bowel and lung cancer.
It works by picking up fragments of DNA released into the blood by fast-growing cancer cells, the Daily Mail reports.
In a study of more than 1,400 people, the triple test achieved up to 90 per cent accuracy.
Among four cancer-free people who tested positive, the US authors say two women were diagnosed with ovarian and endometrial cancer just months later.
The authors, led by Cleveland Clinic in Ohio, will present their findings at the annual conference of the American Society of Clinical Oncology in Chicago, and hope the test could be available within five to 10 years for healthy people who are cancer-free.
Dr Eric Klein, lead author of the research from Cleveland Clinic's Taussig Cancer Institute, said: "This is potentially the holy grail of cancer research, to find cancers that are currently hard to cure at an earlier stage when they are easier to cure, and we hope this test could save many lives.
"Most cancers are detected at a late stage, but this 'liquid biopsy' gives us the opportunity to find them months or years before someone would develop symptoms and be diagnosed."
The results to be presented at the US medical conference are for more than 1,400 people, of whom 561 were cancer-free, with no diagnosis, while 845 had been newly diagnosed with the disease.
A new blood test can detect 10 types of cancer potentially years before someone becomes ill. Photo / 123RF
The blood test they were given is expected in the real world to deliver a result in one to two weeks.
It found early warning signs in the blood for 10 types of cancer with accuracy of more than 50 per cent.
The best results were for ovarian and pancreatic cancer, diagnosing 90 and 80 per cent of people with these diseases.
Four out of five people were also successfully diagnosed with liver and gall bladder cancers.
For blood cancers lymphoma and myeloma, it was 77 and 73 per cent accurate, while correctly diagnosing two-thirds of people with bowel cancer.
The results for triple-negative breast cancer were 58 per cent, and the test also detects lung, gullet and head and neck cancers with more than 50 per cent accuracy.
It was less able to pick up stomach, uterine and early-stage low-grade prostate cancer.
Dr Klein, whose research team also involved Stanford University, said: "Potentially this test could be used for everybody, regardless of their family history.
"It is several steps away, and more research is needed, but it could be given to healthy adults of a certain age, such as those over 40, to see if they have early signs of cancer."
But academics say it is much more sensitive than previous tests.
Currently, for cancer, there is just one blood test available to diagnose people before they find a lump or initial symptom. This is the notoriously unreliable PSA test for prostate cancer.
The new test has three parts, testing the whole genome for DNA fragments first, then searching for specific genetic mutations and finally DNA methylation - a process which changes the way genes work when someone has cancer.
It is part of a new generation of "liquid biopsies" which have advantages for early detection of cancer over traditional biopsies which remove tissue, such as part of the breast or lung, from someone's body.
Professor Nicholas Turner, from the Institute of Cancer Research, London, described the findings as "really exciting" and could be used for "universal screening".
