Liquid biopsy, increasingly used in the diagnosis of cancers, is full of promise. It allows a dynamic analysis in real time of the evolution of the tumor of the patients, practiced in a non-invasive way and at a lower cost.
Microfluidics is the science and technology of systems manipulating fluids and of which at least one of the characteristic dimensions is of the order of a micrometer. In the medical sector, its promises are numerous. In particular, it makes it possible to manufacture miniaturized laboratories of barely 1 or 2 cm which allow faster and less expensive analyzes with a minimum of reagents. One of its applications, the liquid biopsy, is revolutionizing the diagnosis and treatment of certain cancers. It is indeed an inexpensive, non-invasive and therefore less risky practice, which allows real-time dynamic analysis of the evolution of the patient’s tumor. Why Doctor takes stock.
Liquid biopsy “consists of analyzing elements from the tumor in the biological effluents of patients”, explains Valerie Taly, research director at the National Center for Scientific Research (CNRS) at Medical Frequency. “It can be circulating tumor cells and for a very long time this was essentially the case, but we can also have other biological elements including circulating tumor DNA which is the element on which we are particularly working”, continues- she. In addition to blood, it is possible to find elements of the tumor in other liquids such as urine, saliva or semen.
Thanks to this technology, it is now possible to answer precisely the question: Is there a cancer? “It is intended to give answers as precise as that with characteristics of cancer and therefore therapeutic directions. Has it spread, will it respond to such treatment, what genetic changes have occurred in the tumour?”, explains Professor Jérôme Bibette, physicist and chemist, microfluidics specialist and director from the Institute of Chemistry and Biology Innovation (ESPCI) at Frequency Medical, emphasizing the prospect of more personalized treatments depending on the patient.
“We can speak of a small revolution”
“This biopsy uses digital microfluidics. The small droplets make it possible to analyze one by one the cells circulating in the blood and to have the phenotypic characteristics (the expression of genes in an observable way) of each of these cells, therefore information related to cellular diversity”, he specifies. So the machine calculates automated measurements, and then the human takes that data and assesses what’s happening at the individual cell level.
“I take certain volumes of blood, I cut them into infinitely small volumes. In each of these volumes, there is a cell and each of these volumes is analyzed by a routine method which makes it possible to say what comprises this cell: is it cancerous, does it have certain mutations? How should we consider it in this whole? Is it responsible for cancer? Should we treat it?” continues Jérôme Bibette.
At present, microfluidics via the application of liquid biopsy is already part of the daily life of pulmonology departments and extends to breast cancer diagnosis and colon. And, for some cancers, clinical biopsy has, in addition to allowing a better diagnosis, helped in remission because it is now possible to see if there are any cancerous cells remaining after treatment. “We cut the sampled volume into such small elements that we are sure not to miss anything and we are sure to have an absolute answer. We can talk about a small revolution, it opens up enormous possibilities”, enthuses Jerome Bibet.
Less risk, more savings
The great novelty of the process also relates to patient comfort. Indeed, a urine or blood analysis is much faster and more comfortable than a classic biopsy. Prior to this, the only way to get a formal diagnosis of cancer was through a tissue biopsy. To do this, doctors take a sample of tissue that comes directly from the suspected tumor and examine it under a microscope to see if it contains cancer cells. If the cancer comes back or a treatment fails, they sometimes have to repeat the biopsies and the patient is exposed to new risks each time.
And finally, the liquid biopsy promises many savings. “In micro drops, millions of tests are carried out within an hour by a machine. Apart from the fact that we will learn more things, we will save money,” explains Professor Bibette, who hopes that this technology will soon be accessible to everyone. And to launch an appeal to all future researchers: “This is still a very exciting field for our young scientists, there is still a lot of room for innovation.”
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