Introduction:
The dreaded "liquid biopsy" is swiftly making the transition from laboratory study to clinical application in lung cancer and other human cancers. The "liquid biopsy" is no longer a pipe dream but rather a reality that is improving therapy selection and patient monitoring for lung cancer patients in oncology departments and hospitals across the globe, even though its full potential has not yet been realized. One day, "liquid biopsy-based tests which provide priceless diagnostic, prognostic, predictive, and monitoring data will be as common and beneficial as "standard" biopsies and imaging methods.
Blood testing and other bodily fluid tests are commonly referred to as "liquid biopsies." The goal of those tests for cancer patients is to find materials that originated in the tumor. Despite being widely used, many pathologists disagree with the phrase "liquid biopsy." They assert that the so-called "liquid biopsies" are not authentic. A "true" biopsy is typically carried out by a pneumologist or surgeon and entails the removal of sample tissues or cells, which are then often viewed under a microscope by a pathologist following some sort of fixation and staining. Another common technique is paraffin embedding.
Real biopsies are invaluable sources of information that cannot be gained by any other method, such as tumor kind and histology, and “liquid” biopsies will never be able to replace them. They do, however, provide a wealth of extra information that is not available any other way.
Genetic testing for targeted therapy can only be done through "liquid biopsy," which is the sole option for individuals who cannot be biopsied or whose biopsies do not include sufficient tissue. Additionally, it is impractical to take biopsies at each metastatic location in individuals with advanced illness. However, blood travels to the original tumor and its metastases, and a "liquid biopsy" can contain elements from both. Lastly, blood may be taken frequently without running the risk of comorbidities, unlike "real" biopsies, and be used to track the progression of the illness, including early detection of response, recurrence, or the establishment of therapy resistance.
What Is Liquid Biopsy?
With a straightforward blood sample, a liquid biopsy is a non-invasive, easy substitute for surgical biopsies that allows medical professionals to learn a variety of details about a tumor. Blood traces of cancer's DNA (deoxyribonucleic acid) can provide information about which treatments are most likely to be effective for that particular patient.
Physicians can select the best course of treatment for a patient at the right moment with the use of a liquid biopsy test that can identify epidermal growth factor receptor (EGFR) gene mutations, which affect 10-35 percent of patients with non-small cell lung cancer (NSCLC).
Although lung, breast, and prostate cancers have accounted for a large portion of the early research on liquid biopsies, it is anticipated that this technology will impact all forms of cancer.
Liquid biopsies are less intrusive than surgical biopsies, requiring only 5 milliliters of blood, which makes them easier to bear and expedites the process. After that, the blood sample is "spun down" to extract two milliliters of plasma, which can be used to check for tumor DNA.
For patients, convenience and tolerability are huge benefits. The primary advantage of liquid biopsies is their ability to identify therapy resistance or disease progression long before they manifest clinically or show up on imaging studies.
The majority of cancers contain several genetic abnormalities, some of which may not be present in every area of the tumor.
Liquid biopsies have a better probability of identifying these genetic alterations than tissue samples retrieved for biopsy, which might not reveal all mutations. When it comes to cancer testing, liquid biopsies may prove revolutionary. The advantages of quick, simple, and repeatable non-invasive diagnostics are evident when it comes to patient acceptability and disease treatment. Additionally, liquid biopsies may be utilized in the long run to detect cancer early on, before symptoms appear. From the standpoint of treatment, "the greater availability of liquid biopsies, particularly for patients who are unable to undergo a new invasive biopsy or do not have tissue available, could greatly increase the number of patients who will benefit from potent targeted medicines, particularly in lung cancer."
Tissue could also be set aside for other cutting-edge testing, such as cancer immunotherapy, for which there are currently no blood tests available. Ultimately, the ability of liquid biopsies to increase survival and progression rates will determine whether or not they become a top diagnostic tool.
Will Tissue Biopsies Become Reluctant in the Future?
The treatment of cancer may undergo a revolution thanks to liquid biopsies. Tissue biopsies are still useful, but there are obstacles to the broad application of this new strategy. Obtaining and analyzing tissue samples is still the gold standard, far from becoming redundant.
There are still some unanswered questions regarding liquid biopsies because the technology is still in its infancy.
For instance, how much do different tumor kinds and illness stages affect test accuracy? Is there a bias to particular sub-regions or does the liquid biopsy provide a representative sampling of all the genetic clones in a tumor? Currently, researchers are trying to find the answers to these queries. In addition to tissue biopsies, liquid biopsies will enable testing of a larger number of patients.
According to experts, "the liquid biopsy will not replace the tissue biopsy shortly." However liquid biopsies will supplement tissue biopsies so that more patients can be examined. The problem is that there is frequently insufficient tissue available for testing.
The problem is that there is frequently insufficient tissue available for testing. This new, less invasive method may influence patient care and alter the landscape of prognosis and prediction for lung cancer genotyping. Although I believe we are getting close, we are still a way off.
The potential of plasma-based diagnostics has to be fully explored through more real-world clinical investigations and comparisons. In many ways, it is a win-win situation for the patient. The usefulness of liquid biopsies in the medical context needs more confirmation through clinical trials.
Furthermore, although therapy choices for lung cancer containing an EGFR mutation are guided by liquid biopsy, not all tumors respond well to targeted therapies. Are liquid biopsies the most effective way to identify and track these cancers? In the nascent science of immunological oncology, what, if any, part do liquid biopsies play in helping with therapy choices? Scientists and medical professionals are still investigating these concerns.
"It would be a breakthrough to use a blood test instead of relying on tissue as sometimes a (surgical) biopsy doesn't take enough tissue". "There is hope for the future, even though the science isn't quite there yet."
But as science progresses, scientists are discovering more about how liquid biopsies might identify mutations, indicating that this diagnostic technique has enormous promise and ability to change the course of history.
Tissue Biopsy Versus Liquid Biopsy:
A minimally invasive method, liquid biopsy can be used for serial monitoring and spares users from the risks associated with surgical biopsies. Tissue can be stored in clinical trials or additional studies like immunohistochemistry linked to immuno-oncology thanks to liquid biopsy. Because blood samples contain ctDNA that is continuously produced into the bloodstream from various locations of primary and metastatic tumors, liquid biopsy is capable of analyzing comprehensive and real-time molecular profiling of the tumor.
Liquid biopsy has several drawbacks despite these benefits to wider use. Because of the low proportion and significant fragmentation of ctDNA, ctDNA detection requires more sensitive techniques than conventional methodologies like Sanger sequencing or pyrosequencing.
Conclusion:
When a tissue biopsy cannot be performed, EGFR mutation detection in liquid biopsy specimens can be utilized to guide EGFR TKI treatment, despite the unclear mechanism of ctDNA release and clearance. For a variety of malignancies, liquid biopsy will be an important prognostic, predictive, and diagnostic tool. For the best care of cancer patients, pathologists should be able to combine the molecular test results from the liquid biopsy with the morphological features of pertinent tissue, comprehend preanalytical factors and various assay performances, and work in a multidisciplinary team environment.
