What Is A Liquid Biopsy?
A liquid biopsy, or a fluid biopsy, is a method of characterizing a tumor. It is also known as a test of blood-based biomarkers. Until now, the only method that made it possible for medical professionals to find out what type of tumor a patient had was a tissue biopsy. However, tissue biopsies have a number of limitations. This initiated the development of new and less invasive techniques, such as liquid biopsy.
These types of methods search for, quantify, and characterize tumor cells, as well as their nuclear DNA or tumor DNA, which circulate in the blood of patients with certain cancers. The most sought after goal is to count the tumor cells in the blood to predict survival. The more tumor cells a patient has, the worse the prognosis. This type of method is used in breast, prostate, colon, rectal and lung cancers, among others.
A liquid biopsy can be of any biological fluid, such as blood, urine or pleural fluid. These fluids can establish a biomarker that, just like in tissue biopsy (also known as tissue sample), represents the tissue that produced the biomarker.
Limitations of tissue biopsy
As we mentioned above, tissue biopsy, despite being one of the best methods for determining the characteristics of a tumor, has a few limitations. First, it requires a tumor sample. In other words, it is an invasive technique that requires surgery, which can be uncomfortable for the patient.
As with all surgery, it may not be a suitable option for all patients in vulnerable situations, or in advanced stages of the disease. Another limitation is that the tissue selected for biopsy may not be the most suitable. It may also not be relevant for the overall assessment of the tumor. In addition to this, it can take several days before the results are ready.
On the other hand , a tissue biopsy only allows doctors to know the mutation status of the tumor at a specific time. In order to follow up the patient’s status, they should therefore undergo several operations as the disease progresses. If the sample was taken a long time ago, and at a different stage of the disease, it may not be the best choice to determine the patient’s first treatment.
A final limitation is that, depending on the location of the tumor, it may sometimes be impossible to perform a biopsy. In these cases, a liquid biopsy comes to the rescue.
The benefits of liquid biopsy
A liquid biopsy provides the benefit of quickly detecting mutations in certain types of tumors in a sensitive, practical and reliable way, for both the patient and the oncologist. It also allows the detection of mutations in DNA, which are found in the blood to determine the best available treatment options.
Furthermore, it is much less invasive than a traditional biopsy. To perform a fluid biopsy, a medical professional must simply perform a blood test, using advanced and ultra-sensitive analytical techniques, such as BEAMing technology.
Since it only requires a blood sample, a liquid biopsy can be performed without affecting the patient’s well-being. In addition, it is more accessible to a larger number of patients than a tissue biopsy. This fact implies the possibility of obtaining disease data in real time.
Finally, we will also mention that a liquid biopsy is representative of the whole tumor, not just part of it. It also allows you to monitor the disease over time. This was a limitation of traditional biopsy.
When you should perform a liquid biopsy
A liquid biopsy is perfect when a medical professional could not get enough tissue from a tissue biopsy. Another indication is when the tumor is located in a place that is difficult to access. Some of these difficult places are:
- The brain
- The legs
- The lungs
In addition , it is recommended when the patient does not respond to treatment, and when the patient refuses to undergo another traditional biopsy.
Conclusion
A liquid biopsy is a very useful method that can replace the invasive tissue biopsy technique. It has many advantages over traditional biopsy. However , experts are still studying it to discover additional uses.
