- The earlier cancer is detected, the better a patient's chances of recovery
- Now, a new test is able to pick up some cancers in the blood of people who are still asymptomatic
- It represents a 'robust preliminary demonstration' of the early detection of cancer four years before conventional diagnosis
One of the key factors in successfully treating and managing cancer is early diagnosis. While some cancers can be treated early, many people don’t spot the signs soon enough.
Now, a new blood test developed by a startup named Sino-US found cancers in 91% of people who presented with no signs or symptoms when the blood tests were collected, but were diagnosed one to fours years later with stomach, oesophageal, colon, lung or liver cancer, according to a study published on 21 July 2020 in the journal Nature Communications.
What the research entailed
In the study, 123 115 seemingly healthy participants provided blood samples for long-term storage, and were then screened for cancer over the years.
The blood test, referred to as PanSeer, detected five types of common cancers in more than 600 participants who donated their plasma.
The scientists used the new test to analyse blood samples taken up to four years earlier from 191 patients who were diagnosed with cancer. These test separately detected cancer in the blood of 113 patients who had already been diagnosed by the time the blood samples were collected. (The test showed an accuracy of 88%.)
How does the test work?
This screening technique was developed over a decade and works through a process known as DNA methylation analysis. This means that certain DNA signatures specific to some cancers could show up in the blood of someone who is still asymptomatic.
Past research has shown that abnormalities in this methylation process may be showing signs of various types of cancer, including pancreatic and colon cancer.
The Panseer test detects the methylation by isolating DNA from the blood and then measuring DNA methylation in 500 locations previously identified as having the greatest chance of signalling potential cancer.
An algorithm based on machine-learning compiles the results into one score, which can indicate the possibility of a person having cancer.
Will this blood test work in a clinical setting?
According to Colin Pritchard, a molecular pathologist at the University of Washington School of Medicine, who was not involved in the research, the new study does offer an interesting approach as we strive for a blood-plasma cancer detection method that is non-invasive. But he does state that it’s vital for another independent research team to validate the findings in a different group of people.
“The authors are not suggesting that they have a test that can be used clinically at this stage. They are clear that what they have is a robust preliminary demonstration of early detection of multiple cancer types four years prior to conventional diagnosis,” stated Usha Menon, a a professor of gynaecological cancer at University College London, who was also not involved in the research.
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