A liquid biopsy is a blood test that aims to search a patient’s blood for fragments of the DNA of a tumor or cancerous cells.
Will doctors soon test blood to evaluate the effectiveness of a cancer treatment or catch a tumor very early? Scientists are exploring all the possibilities of this field, which will inevitably become approved methods in the future.
Dozens of studies are underway to demonstrate the usefulness of using a new tool, the “liquid biopsy”, to track the condition of patients receiving cancer treatment.
A liquid biopsy is a blood test that searches a patient’s blood for DNA fragments from a tumor or cancer cells.
This technique has enormous benefits and a number of observers consider that its discovery deserves the Nobel Prize for Medicine, especially since it is much less invasive than a “traditional” biopsy that cuts a sample of body cells.
This technique especially involves very accurate information about the cancer that the patient suffers from, and the expert on this subject, Alain Thierry, director of research at the Institute for Research in Cancer Science in Montpellier, southern France, explained that “taking a sample of what is called rotational DNA aims to monitor mutations.” for some types of cancer, thus adapting treatments to suit it.”
In some cases of cancer, such as lung cancer, where it is difficult to reach the tumor, this technology will constitute a real advance.
Analyzing patients’ blood may soon also allow monitoring of how cancers respond to treatments. “In practice, after removing a tumor through surgery, we often prescribe chemotherapy when we don’t know if the patient really needs it,” Thierry said.
Blood analysis will allow in many cases in the future to prescribe less severe or shorter treatments for the patient, but also to monitor any possible new infection.
Liquid biopsy still has other possibilities, though it’s not yet clear. “There is an amazing possibility of early detection of cancer,” said Alain Thierry.
Many biotechnology teams and companies around the world are working on this possibility, and the goal is to detect a cancerous tumor in a person through a sample of his blood before symptoms appear or before it can be detected on an X-ray image.
“Technologically, it is much more complex than tracking cancer, because it requires a large-scale analysis of mutational mutations in DNA on a large scale, but also other markers,” said François-Clément Bidar, an oncologist at the Institut Curie in Paris and head of the circulating cancer biomarkers laboratory. specific, without knowing in advance what we are looking for.
A recent study conducted by the American company “Grail” for biotechnology gave remarkable results, as a blood test during the experiments allowed the detection of cancer cases in individuals aged fifty years and over and in apparently good health. More than 6,600 people were examined, and the results reflected suspicions of cancer, 92 of them. In the end, 35 actually developed confirmed cancers during the year, meaning 57 people were mistakenly believed to have cancer.
However, the experience allowed the detection of nine cancer cases that would not have been shown by traditional early detection methods.
However, the outcome remains very mixed and it will inevitably take years before the reliability of these tests, which are now being marketed in the United States, is enhanced.
François Clement Bidar warned that even if they prove reliable, these tests will still raise some questions.
“One of the issues is the cost, as this type of DNA sequencing is very, very expensive,” he explained. “Another issue is the potential for ‘overdiagnosis’ resulting from these tests, because a number of the cancers that are being detected are in fact very slow and insufficient to develop.” necessarily requires treatment.
Scientists should also prove that these tests constitute a tangible development compared to the methods currently adopted.
“Today, despite everything, we have an advanced strategy for detecting cancer,” said Professor Fabrice Parlessi, Director General of the Gustave Rossi Center for Cancer Control in the Paris region, but “the participation rate does not exceed 40% in the best cases” in these screening tests offered by health insurance.
However, he did not rule out that these tests would be adopted by examining a blood sample in the future as a “complementary” method.