Blood test for cancer detects eight different types of tumour
Jan 20 2018 by Kristina Bennett
Many of these tests are created to detect a single kind of cancer by spotting tumour-associated mutations in DNA sequences found floating freely in the blood.
-Ph.D. student at the Johns Hopkins University School of Medicine and the paper's first author explained that the DNA from the tumors carry mutations that are specific for the cancer. The test was able to find sings of cancer in 70 percent of them. Sensitivity ranged from 69 percent to 98 percent for the five cancers that now have no routine screening tests, the researchers report.
With cancer risks rising from the age of 50, he said, the test would be most important to older people, but also for younger people whose family histories might put them in a high-risk category.
In addition to identifying the type of cancer, CancerSEEK can direct physicians toward the cancer's location in a patient's body.
In a statement, Australian scientist Professor Peter Gibbs, who contributed to the research, said the test was urgently needed because cancer mortality rates are directly related to how advanced a cancer is at diagnosis. In contrast, the CancerSEEK test "utilizes combined assays for genetic alterations and protein biomarkers and has the capacity not only to identify the presence of relatively early cancers but also to localize the organ of origin of these cancer". One startup, Grail Bio, has raised over $1 billion in pursuit of a single blood test for many cancers.
For 5 types of cancers that have no screening tests - ovarian, liver, stomach, pancreatic and oesophageal cancers - sensitivity ranged from 69% to 98%.
The past few years have seen a bevy of experimental tests calledliquid biopsies that hold the promise of detecting and tracking tumours from a simple blood draw.
The Johns Hopkins researchers and collaborators found that gains in the detection rate tailed off when they added more genes to their test.
Papadopoulos and his collaborators believe the test might cost $500 if it eventually comes to the market. However, researchers in the United States have reported that they are a step closer to developing a cancer screening tool that requires just a sample of blood. Both CancerSEEK and a PSA test look for proteins. Others all the more as of late have concentrated on DNA from tumors.
The Lustgarten Foundation says another round of clinical trials will be conducted before it goes to the FDA for approval. All the tests were done on people already diagnosed with cancer. The scientists at the Hopkins are now testing their test on tens of thousands of apparently healthy volunteers who are enrolled in the Geisinger Health Plan in Pennsylvania.