A liquid biopsy, also known as fluid biopsy or fluid phase biopsy, is the sampling and analysis of non-solid biological tissue, primarily blood. Like traditional biopsy this type of technique is mainly used as a diagnostic and monitoring tool for diseases such as cancer, with the added benefit of being largely non-invasive.
Contents
Although a liquid biopsy of circulating tumor cells has been validated and approved by the FDA as a useful prognostic method for various types of cancer, its clinical implementation is not yet widespread.
Types
There are several types of liquid biopsy depending on the condition that is being studied.
A wide variety of biomarkers may be studied to detect other diseases. For example, isolation of protoporphyrin IX from blood samples can be used as a diagnostic tool for atherosclerosis. When studying the central nervous system, cerebrospinal fluid may be sampled instead of blood.
How it works
Unlike traditional biopsies, liquid biopsies remove the need for invasive surgeries and procedures by instead allowing medical professionals to test for signs of cancer from a simple blood-draw. As a result, biopsies are easier to perform, giving hope to many that they will lead to earlier diagnoses of cancers in patients.
Liquid biopsies have been made possible by advances in sequencing the human genome since scientists and researchers can now detect genetic mutations of cancers. Researchers have found that unique cancer mutations can show up in microscopic fragments of DNA in a patient's blood. Tumor-related circulating-free DNA, RNA or proteins are released by tumor cells and circulate in the blood of cancer patients. Therefore, assays using these molecules can be used for early tumor detection, monitoring or detection of resistance mutations.