To be more precise, a liquid biopsy is a particularly innovative technique whereby biological material for molecular analysis is obtained through the extraction of body fluids, and which provide a broad range of information on the biology of the tumor. Undoubtedly, the benefits obtained are the result of the development and recent availability of new, high-performance technologies making it possible to do simultaneous massive genetic analysis of a small sample. “With a blood test, for instance, free DNA fragments of a tumor can be detected or circulating tumor cells, which can give us an overall idea of what is happening in a disease that is as heterogeneous as cancer is”, explains the doctor.
But blood is not the only fluid that can provide information on what is happening inside the organism: “we are beginning to test these technologies on samples of cerebrospinal fluid to detect metastasis in the brain, samples of bronchial aspirate to diagnose lung cancer, uterine flushes for endometrial cancer, or samples of urine, of saliva…”, the doctor goes on. This information, in addition to all the other, more traditional methods of diagnosis, will have an effect, in the immediate future, on the approach to cancer treatments.
Experts are particularly hopeful about the results achieved that already reflect the prompt application of these tools. Indeed, at MD Anderson Cancer Center Madrid, significant data has been compiled confirming that by means of liquid biopsy, a greater number of mutations, genetic alterations, can be detected, which gives a clearer picture of the variations the tumor may have.
“We find ourselves before an excellent diagnostic tool - non-invasive, that is easy to repeat and is somewhat more economical, and will improve the diagnosis and clinical monitoring of any tumor before treatment, in addition to monitoring the presence of metastasis early on”, states Dr. Moreno-Bueno.
Another weapon in tailored medicine
Having access to so much more information, to a more accurate map of what is happening at every moment inside the patient, allows treatments that are most suitable in each case to be adjusted much more as the disease progresses. “We are beginning to understand the dynamics and clonal evolution of the disease, and the changes that may take place over time, between different sites in the body, and on occasions brought about by the treatment itself. Due to all the factors favoring the application of liquid biopsies, we are confident that this could be a key tool in long term monitoring of cancer”, points out Dr. Juan Fernando Garcia, head of the Anatomical Pathology Service at MD Anderson Cancer Center Madrid.
On that premise, medical research endorses a combined, parallel approach in the presence of different molecular alterations in a single tumor. In the words of the MD Anderson Madrid specialist, “it is important to recognize the advantages of the synergy of combined treatments over different treatment targets; it is clear that we will gain the advantage if we are in a position to attack the different alterations in a tumor simultaneously”.
For that reason, more and more clinical studies begin with the initial analysis of the genome of a tumor and use liquid biopsy as a method to monitor the tumor, which avoids the need to extract tissue on numerous occasions using conventional biopsy techniques or much more aggressive surgical techniques. “We are already changing the classical idea that approaching cancer is based on a still photo of the disease and we believe more and more in dynamic knowledge of the disease. It is clear that easy access to the enormous amount of instant information provided by tools such as a liquid biopsy will be one of the principal advances in oncology in the coming years”, concludes Dr. Garcia.