Liquid biopsies for the detection and monitoring of brain tumors have considerable potential, reaffirm these scientists from the Cancer Research Institute UK who are making progress in the development of liquid biopsies detecting tumor DNA in cerebrospinal fluid (CSF). Their liquid biopsy technique, tested here in 13 patients presenting with a glioma, makes it possible to detect tumor DNA in 5 of these patients. Promising results, presented in the journal EMBO Molecular Medicine.
Liquid biopsies are fluid or liquid samples from patients, from blood, urine, saliva, or CSF. These biopsies offer the means to detect or monitor the disease in a less invasive way than tissue biopsies. This less intrusive test finds its natural application for the diagnosis of tumors that are difficult to access, such as brain or lung tumors, where tissue sampling can be complex and risky for patients.
Scientists from the Institute of Cancer Research UK (Cambridge) are here analyzing the CSF, the fluid that bathes the brain and spinal cord of 13 patients with glioma and using an inexpensive and widely available technique of whole genome sequencing, they managed to detect tumor DNA in 39% of them. New here is the examination of the size of the mutated DNA fragments, which are shorter than those from healthy cells. This other means of detecting tumor DNA seems to make it possible to increase the detection rate.
Liquid biopsy is sometimes more "fine" than conventional biopsy: in one of the patients, the researchers compare the genetic modifications identified via tissue analysis and CSF analysis. While overall these changes appear broadly similar, CSF delivers undetected changes in some tissue samples, suggesting that liquid biopsy by CSF analysis may more accurately reflect the spectrum of genetic alterations associated with brain tumors.
Liquid biopsies thus confirm their promises: “even if”, underlines the main author, Dr. tests for brain tumors have lagged due to low levels of tumor DNA present in body fluids, especially blood. . However, this small study shows that an inexpensive and available technique can be used to analyze tumor DNA in cerebrospinal fluid. The idea is therefore to use this technique more widely to identify patients likely to benefit from other tests likely to contribute to the monitoring of their disease and to be able to opt for more personalized treatments.
Professor Charles Swanton, Chief Clinician at Cancer Research UK, concludes: “ Brain tumor survival remains low and there is an urgent need for further research to identify strategies to better manage these complex diseases . ” This study lays an important foundation for developing liquid biopsies.
The researchers will continue with a larger number of patients and refine the approach so as to be able to adapt it in clinical practice, whether in the diagnosis or the monitoring of the response to treatment in the management of brain tumours.
