Firstly, this is the question most of us will be asking ourselves: what is liquid biopsy? Liquid biopsy is (Oxford Languages definition) “a test that enables the diagnosis or analysis of tumours using only a blood or fluid sample rather than a solid tissue biopsy.” Or in simple terms, an alternative, non-invasive test which allows you to detect tumours through blood or a sample of fluid rather than removing any skin making liquid biopsy require less blood, less pain and have a lower risk of complication.
Currently, there are 2 methods which are used in liquid biopsy to detect cancer. Both methods involve the sequencing of DNA which is a technique called electrophoresis. Electrophorsesis separates miniscule fragments of DNA that differ in length by only one base. The DNA is then sequenced by placing it at one end of a gel (slab made up of a gel-like substance). The first method utilises the sequencing of circulating tumour cells which involves capture through various selection method then isolation and sequencing of these cells. Circulating tumour cells are often easily identifitied due to their size and texture. They are often much larger in size and have feel firmer compared to healthy blood cells. The second method is cell-free DNA which is the actual DNA that is shed into the plasma and is then sequenced. Here, the blood is first centrifuged(separating fluids with a variety of densities) to isolate the biomarker (a biological molecule in the blood which shows a sign of an abnormal process).
Many companies such as Inivata are pioneering liquid biopsy today. Inivata is a good example of a company who is thriving and leading liquid biopsy. Liquid biopsy is life-changing as it is able to unlock genomic information from a simple blood draw rather than removing any skin! Inivata along with many other companies use this revolutionary technology today to discover any targetable genomic alteration and guide proportional targeted therapy.
In 2018, there were approximately 9.6 million deaths worldwide due to cancer. Thanks to the latest development of next-generation sequencing about 211 out of 419 patients with Glioblastoma multiforme (a rare type of cancer starting in the brain) have a detectable circulating tumor DNA (ctDNA) showing high potential in clinical utilies and liquid biopsy more specifically. Many prominent individuals like Steve Jobs have had liquid biopsies taken and Steve Jobs actually found out he had pancreatic cancer.
Liquid biopsy is an extraordinary advancement in the cancer industry. So much so that liquid biopsy is providing an amazing alternative to cutting skin. Especially as it is difficult to determine the stage of metastatic lesions in the tissues so liquid biopsy is efficiently able to provide a reliable alternative!