Liquid biopsy is a collection of body fluid such as blood, urine, or amniotic fluid to detect DNA fragments circulating in the fluid known as cell-free DNA (cfDNA). In fact, the sampling for cfDNA has been used for quite some time, one of the most commonly used cases is the NIPT (Non-invasive prenatal testing) for pregnant women to indicate the risk of a fetus bearing genetic diseases such as Down syndrome.
At present, with more advanced technology and research available, the sampling and analysis of cfDNA is adapted and used in detecting a wider range of diseases from liver diseases, many types of cancer, to COVID-19 as it helps medical staff to follow up with the stage of the disease.
With more use cases, investments are being offered to companies with this technology. We can see from the figure that investment is growing higher every year. In 2019, there were over 1.6 billion US dollars invested in business related to liquid biopsy and the number has soared to 2.8 billion US dollars in 2020 (Source1).
One of the biggest deals last year was when Illumina, the US company producing sequencing machines, took over GRAIL, a startup company working on liquid biopsy (startups use liquid biopsy as a common term of cfDNA testing) at 8 billion US dollars. Another was Exact Sciences who bought Thrive Earlier Detection at over 2 billion dollars.
The use case which grabbed the most attention and attracted a large sum of investment from the investors is using cfDNA to detect cancer, as known as cancer screening.
As cancer is resulting from the deformity or abnormality of cells, it does not only grow very quickly, it can also die and leave residuals circulating in human plasma. Therefore, blood samples can be collected to detect those fragments or circulating tumour DNA shredded from cancer cells with high sensitivity.
Benefits of using liquid biopsy to detect cfDNA of cancer (also known as ctDNA - circulating tumor DNA) are:
Less invasive - Blood draw is less invasive than a tissue biopsy. It’s also faster, easier, more affordable, and can be tested as many times as needed to follow up with the stage of the disease.
Tumor accessibility - Some tumors grow in areas where the tissue biopsy is not viable such as brain, lungs, or organs deeper in our body. Liquid biopsy can be used to identify whether the tumor found on x-rays is cancer by detecting its ctDNA. There will be no more waiting for the tumor to grow larger to examine but becoming harder to treat, giving more chances for patients to recover.
More information gained - Tissue biopsy only contains information at the area the tumor is developing while cfDNA can also indicate metastatic tumor (secondary tumor) as well as identify the stage of cancer more accurately.
In addition, liquid biopsy is not only limited to early detection for cancer, it can also be used to follow up and detect recurrence. The blood draw can be done periodically to check if ctDNA detected indicates that cancer might come back, full diagnostics and treatment can be started sooner for a better recovery.
From our case, a former breast cancer patient who had been through a complete treatment until fully recovered, came to Panacura for a liquid biopsy to see whether there is any chance of cancer recurrence. Normally, cfDNA of cancer in healthy people is 0% but it’s 8% in this case. As little as it may sound, in a medical perspective, this is an indicator of recurrent cancer which needs to get a full diagnostics to confirm.
Liquid biopsy for detecting cfDNA is still an innovative technique in Thailand and Southeast Asia region. Yet soon it will become a standard and popular way of health checkup and cancer screening as it’s cheap, non-invasive, and can decrease the mortality rate of patients in the long run.
Source 1: https://www.cbinsights.com/research/cell-free-dna-tech-diagnostics/
ARTICLE WRITTEN BY: BARAMEE NAVANOPPARATAKUL Baramee Navanopparatskul is the CEO of Panacura.