A blood test for ten different types of cancers could one day help doctors screen for the disease before patients show symptoms, researchers at the world’s largest gathering of oncologists have said. The test, called a liquid biopsy, screens for cancer by detecting tiny bits of DNA released by cancer cells into the blood. The test had particularly good results for ovarian and pancreatic cancers, though the number of cancers detected was small. Researchers hope the test will become part of a “universal screening” tool that doctors can use to detect cancer in patients. “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,” said Dr Eric Klein, lead author of the research from Cleveland Clinic’s Taussig Cancer Institute. “We hope this test could save many lives.” The study, by a research team that also included scientists from Stanford University, was presented at the annual conference of the American Society of Clinical Oncologists in Chicago.
Simon Stevens, the chief executive of NHS England, said “new techniques” such as cancer blood tests could “unlock enormous survival gains, as well as dramatic productivity benefits in the practice of medicine. Now, as the NHS marks its 70th anniversary, we stand on the cusp of a new era of personalised medicine that will dramatically transform care for cancer and inherited and rare diseases,” said Stevens.
The research scrutinised the cases of more than 1,600 people, 749 of whom were cancer-free at the time of the study, with no diagnosis, and 878 of whom had been newly diagnosed with a disease. The test was most accurate for diagnosing pancreatic, ovarian, liver and gallbladder cancers, correctly finding the diseases in at least four out of five patients. The blood test found lymphoma and myeloma with slightly less accuracy, at 77% and 73%, and bowel cancer in two out of three patients. Lung cancer was detected in 59% of patients. Head and neck cancer was detected in 56% of patients.
Researchers said their results showed promise in the approach of blood screenings for cancer but noted further “clinical development” was needed. The number of patients in whom cancers were detected was small. For example, although the test detected ovarian cancer with 90% accuracy, only ten ovarian cancers in total were detected. Nevertheless, researchers aim to develop a tool that could be used by for all people regardless of their family history. “Potentially this test could be used for everybody,” said Klein.
Prof Nicholas Turner from the Institute of Cancer Research in London described the findings as really exciting and as a possible universal screening tool. “Far too many cancers are picked up too late when it is no longer possible to operate, and the chances of survival are slim,” he said. “The goal is to develop a blood test, such as this one, that can accurately identify cancers in their earliest stages.” Klein added: “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.”
Credit: Jessica Glenza for The Guardian, 1 June 2018.