Blood test detects more than 50 types of cancer

Early detection of cancer can have a significant impact on chances of recovery. The National

The results reveal that less than 1% of those without cancer were wrongly identified by the system as having the disease. And in 96% of the samples, the test accurately identified the cancer.

These non-invasive tests analyse circulating tumour (ct) DNA - small fragments of tumour DNA found in the circulation - with the goal of finding out whether or not a patient has cancer. However, as the cfDNA can come from other types of cells as well, it can be hard to pinpoint cfDNA that comes from tumours. When tumor cells die, their DNA, with methyl groups firmly attached, empties into the blood, where it can be analyzed by the new test.

GRAIL's methylation-based technology preferentially targets the most informative regions of the genome and is created to use its proprietary database and machine-learning algorithms to both detect the presence of cancer and identify the tumor's tissue of origin. Others look for different signs of cancer in the blood, such as mutated genes, platelet RNA profiles, damaged white blood cells, elevated levels of certain proteins, and even DNA from microbes that are affected by tumors. The evaluation of this data then takes an adaptive algorithm that has been trained to recognize the characteristic methylation patterns of 50 different types of cancer.

Dr David Crosby, of Cancer Research UK, said: 'The initial results are encouraging.

Many researchers across the globe are trying to develop blood tests - often called "liquid biopsies" -that can detect cancer. The research involved taking samples from nearly 7,000 participants. They were divided into training and validation sets, and a classifier for the detection of cancer and tissue of origin was developed and validated.

In 12 prespecified cancers, the overall detection rate was 67.3%.

The study, published by the Annals of Oncology, tells about the unique and universal test, which is able to detect 50 types of cancer.

Head of R&D, Co-founder and Chief Scientific Officer of GRAIL, Alex Aravanis, M.D., Ph.D., stated that the company believes that early detection of several cancers is capable of reducing the cancer mortality rate. Overall, for Stage I through III cases of the dozen cancers as a group, the test correctly identified the cancer 44% of the time. In all of more than 50 cancer types, the corresponding rates were 18%, 43%, 81% and 93%, respectively.

"The test not only demonstrates the presence of cancer, but provides an accurate address as to the type of cancer and where the health professional should look for the malignancy", immunologist Michael Seiden told HealthDay.

The test still suffers from low detection rates of early-stage cancer as well as difficulty identifying cancers originating from human papillomavirus, but it shows a promising development for AI-based screenings.

The test has a 0.7% false-positive rate for cancer detection, meaning that less than 1% of people tested would be misdiagnosed.

How do current results with the Grail test compare with those reported 2 years ago with CancerSEEK, another cancer diagnostic blood test reported identifying eight common cancers (ovary, liver, esophagus, pancreas, stomach, colorectal, lung and breast ).

The results published by the team are striking. The ongoing studies are assessing the test's performance in even broader populations.

Editor Prof Fabrice Andre said: 'Earlier detection of more than 50 per cent of cancers could save millions of lives every year worldwide and dramatically reduce morbidity induced by aggressive treatments'.

Detection was better the more advanced the disease was. However, the authors said further work could result in testing that would diagnose cancers at a far earlier stage than they would be otherwise.

AI identifying methylated (red) or unmethylated (blue) CpG regions of DNA used to identify the presence or absence of cancer.

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