New blood test to detect multiple types of cancer
One study showed that a new blood test can detect and localize more than 20 types of cancer with a high degree of accuracy. According to the researchers, early detection of common cancers could result in many patients receiving more effective treatment.
The results of the study at a glance:
- In a study by the Dana-Farber Cancer Institute in Boston, a new blood test was able to diagnose more than 20 types of cancer.
- The test was able to identify and localize the cancers with a high degree of accuracy.
- The test uses so-called methylation patterns to detect a possible cancer based on the DNA in the blood.
- The test achieved an overall specificity of 99.4 percent. Cancer was incorrectly reported in only 0.6 percent of cases.
As reported by the Dana-Farber Cancer Institute in Boston, Massachusetts, the test developed by GRAIL, Inc. uses Next Generation Sequencing (NGS) technology to examine DNA for tiny chemical labels (methylation) that influence whether genes are active or inactive.
Almost 3,600 blood samples examined
When applied to nearly 3,600 blood samples - some from cancer patients, others from people who had not been diagnosed with cancer at the time of blood draw - a cancer signal from the cancer patient samples was successfully detected and the cancer was correctly in the tissue from which the cancer originated , identified. The specificity of the test - its ability to only give a positive result when cancer is actually present - was high, as was its ability to locate the organ of origin or tissue.
According to the information, the new test looks for DNA that cancer cells release into the bloodstream when they die. Unlike "liquid biopsies" that reveal genetic mutations or other cancer-related changes in DNA, the technology focuses on modifications to DNA known as methyl groups.
Methyl groups can be bound to DNA to control which genes are "on" and which are "off". Abnormal methylation patterns are more likely to suggest cancer - and cancers - than mutations. The new test examines parts of the genome where abnormal methylation patterns are found in cancer cells.
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More effective treatment thanks to early diagnosis
"Our previous work has shown that methylation-based assays outperform conventional DNA sequencing approaches to detect multiple cancers in blood samples," said study's lead author, Dr. Geoffrey Oxnard, of the Dana-Farber Cancer Institute, which is part of Harvard Medical School in Boston. "The results of the new study show that such tests are a viable means of screening people for cancer."
In the study, the researchers analyzed cell-free DNA in 3,583 blood samples, including 1,530 from patients with cancer diagnosis and 2,053 from people without cancer. Patient samples included more than 20 types of cancer, including breast, colon, esophagus, gallbladder, stomach, head and neck cancer, lymphocytic leukemia, multiple myeloma, lung, ovarian and pancreatic cancer.
The overall specificity was 99.4 percent, which means that only 0.6 percent of the results incorrectly indicated the presence of cancer. The test identified 76 percent of high mortality cancer cases. Within this group, the test accuracy in patients with stage I cancer was 32 percent; at stage II at 76 percent; at stage III at 85 percent and at stage IV at 93 percent.
If the test is widespread, detecting a small percentage of common cancers could result in many patients receiving more effective treatment, Oxnard said. (ad)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
- Dana-Farber Cancer Institute: New blood test capable of detecting multiple types of cancer, (access: 29.09.2019), Dana-Farber Cancer Institute