Determining the right cancer treatment is often a labyrinthian task. Doctors are frequently faced with tough challenges, such as insufficient material, poor tissue quality, or the need for a less invasive method to assess the patient's tumor. The advent of liquid biopsy in the early 2010s introduced a powerful tool to unlock the valuable and potentially life saving data hidden in our blood.
Liquid biopsy, obtained through a single blood draw, extracts cell-free DNA (cfDNA) from blood plasma. This cfDNA can contain circulating tumor DNA (ctDNA), which originates from cancer cells, enabling the identification of genetic mutations and biomarkers associated with cancer. This type of testing can expedite clinical decisions, accelerate results for researchers and clinicians, and streamline patient monitoring.
This relatively new test has proven to be a useful tool to complement traditional solid tumor biopsy. Its overall sensitivity ranges from 60 percent to 85 percent (1); specificity and sensitivity vary according to tumor type, patient health, and other clinical factors.
Liquid biopsy also offers hope as an alternative test for patients who are not candidates for solid tissue biopsies. Studies have shown that nearly 30 percent of non-small cell lung cancers and 20 percent of breast cancers are ineligible for molecular profiling through traditional tissue biopsy. For these patients, liquid biopsy could open the door to more data-driven treatments.
And the evidence surrounding the benefits of liquid biopsy continues to grow. Today, there are over 200 clinical trials evaluating the clinical utility of liquid biopsy, and organizations such as the National Comprehensive Cancer Network, the European Society for Medical Oncology, and the American Society of Clinical Oncology provide guidelines including recommendations that support liquid biopsy as an alternative for certain cancers.
The power of liquid biopsy is encapsulated in every vial of blood drawn. From each small sample, clinicians, virtually anywhere, can unlock a wealth of genomic insights about their patient's cancer. By detecting tumor DNA shed into the bloodstream, doctors and researchers can identify the specific mutations driving a patient's cancer – information that was previously unattainable without invasive tissue biopsies. This opens up a myriad of possibilities: from faster selection of targeted therapies to monitoring treatment response more efficiently – all with minimal discomfort for the patient.
But to truly realize the full potential of precision medicine, liquid biopsy needs to be accessible to labs and patients everywhere – and that requires worldwide collaboration across many constituencies. Today, we are getting closer to this goal. The market for liquid biopsy testing is expanding as more companies develop their own tests. Additionally, some corporations have recognized the power of partnerships and are joining forces with others to optimize, streamline, and increase access to these assays worldwide.
Consider the example of the MSK-ACCESS liquid biopsy assay developed by researchers at the Memorial Sloan Kettering Cancer Center (MSK) in New York. This advanced test is only available for patients who can visit the hospital in the city. So, what if there was a way for patients beyond that single cancer center’s geographical reach to access this molecular diagnostic test? My organization has developed a solution to decentralize this test, making it available to healthcare organizations worldwide.
Such innovation will continue to elevate the field of liquid biopsy and make it available to more patients in more areas of the globe. And though tissue biopsy is still the gold standard, we need all involved in cancer care to realize – and demand – that liquid biopsy becomes a routine part of the diagnosis and treatment process.
To make a change, clinicians must advocate for these tests for patients. Researchers must continue to generate the clinical evidence needed to make liquid biopsy part of the standard of care. Policymakers and payers must remove barriers to access and reimbursement. Diagnostic companies must prioritize approaches that democratize capabilities. And patients and families must demand the most advanced cancer testing available.
Together, we can envision a future where every cancer patient has access to powerful precision oncology insights from a simple blood draw. And cutting edge liquid biopsy testing becomes as routine as standard lab tests, securing timely and personalized treatment for all.
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References
- Cure Today. “A simpler way to sample liquid biopsies in lung cancer” (2020). Available at: https://www.curetoday.com/view/a-simpler-way-to-sample-liquid-biopsies-in-lung-cancer
