A simple blood test that can detect 50 types of cancer has produced some “exciting results” in a new trial, scientists have revealed.
The recent trial involved taking a single blood sample from people who had visited the doctor with a suspicion of cancer due to symptoms like weight loss and unexpected pain.
Out of 5,461 participants, the test detected a cancer signal in 323 people, 244 of whom were later diagnosed. That means it had a positive predictive accuracy of 75 percent. It was also able to successfully rule out cancer in people displaying symptoms with over 97 accuracy.
The results come from the SYMPLIFY study, led by the University of Oxford in the UK and the GRAIL healthcare company, with support from the UK National Health Service. The researchers will be presenting their work at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago on Saturday, June 3.
Known as the Galleri test, it looks for fragments of DNA that have been shed by tumors into the bloodstream. Using next-generation sequencing and machine-learning algorithms, it detects abnormalities in the methylation patterns of DNA that could indicate the presence of cancer.
Importantly, this method is even able to pinpoint where in the body the cancer may be located. Some tumors shed DNA into the blood a long time before people start noticing symptoms, which has some important implications for the early detection of cancer.
Overall, it's able to catch signals from over 50 types of cancer, including many of the biggest killers like lung, breast, colon, pancreatic, and prostate cancer. In this latest trial, the test managed to pinpoint the original site of cancer in 85 percent of positive cases.
"These exciting results will inform our development of an optimized classifier for use in symptomatic patients with a suspicion of cancer," Sir Harpal Kumar, President of GRAIL Europe, said in a statement.
The sensitivity of the test was higher with later-stage cancer, ranging from 24.2 percent in stage I cancers to 95.3 percent in stage IV. Nevertheless, it’s hoped that this kind of test can be used to detect cancer in its early stages when it is easiest to treat and eliminate.
“Earlier cancer detection and subsequent intervention has the potential to greatly improve patient outcomes,” added Brian D. Nicholson, co-lead investigator of the study and Associate Professor at the Nuffield Department of Primary Care Health Sciences at the University of Oxford.
“New tools that can both expedite cancer diagnosis and potentially avoid invasive and costly investigations are needed to more accurately triage patients who present with non-specific cancer symptoms,” he explained.
The study will be presented at the 2023 ASCO Annual Meeting.