Will scientists soon be able to detect cancer and track its progression through a blood test?

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 looks for DNA fragments from a tumor or cancer cells in a patient's blood.

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 takes a sample of the body's cells.

This technique, in particular, 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 progress.

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, as well as to monitor any possible new infection.

Liquid biopsy still has other possibilities, though it's not yet clear. "There is an amazing potential for 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.

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 issues.

"One of these issues is the cost, as this type of DNA sequencing is very expensive," he explained. "Another issue is the potential for overdiagnosis resulting from these tests, because a number of the cancers that are detected are actually very slow progression and do not necessarily require treatment." ".