by What is Liquid Biopsy?
Liquid autopsy refers to a non-invasive blood test that analyzes fragments of DNA shed by tumors into the bloodstream. By detecting circulating tumor DNA (ctDNA) or circulating tumor cells (CTCs), liquid autopsy provides a “window” into what is happening inside a tumor without requiring a tissue biopsy. CtDNA and CTCs contain genetic information that can reveal if a cancer has spread or mutated, helping guide treatment decisions.
How Does it Work?
When cancer cells die, they release DNA into the bloodstream. Liquid autopsy is able to detect this cell-free tumor DNA (ctDNA). Advanced sequencing technologies allow analysis of genetic alterations in the ctDNA. Since ctDNA represents the entire complement of tumor DNA, it provides a genomic profile of all tumor sites, not just the area biopsied. The test is also able to detect CTCs, which are intact tumor cells that have broken away from the primary tumor and traveled through the bloodstream. Analyzing ctDNA and CTCs can reveal information about the mutational landscape of a patient’s cancer.
Applications in Cancer Screening
Liquid autopsy shows promise as a non-invasive screening tool for certain cancers. Since ctDNA can be detected even at early stages Liquid Biopsy may help catch cancers earlier through population-wide screening. Large-scale clinical trials are underway to evaluate the performance of liquid autopsy for screening cancers like breast, colorectal and lung. If proven accurate enough, liquid autopsy screening could spot relapses sooner and potentially reduce cancer mortality through early detection. The test may also identify genetic mutations that predict risk of certain cancers, enabling targeted prevention strategies.
Monitoring Treatment Response and Disease Progression
By tracking ctDNA levels during and after treatment, liquid autopsy provides a real-time picture of how a cancer is responding to therapy. Rapid drops in ctDNA amount after surgery or chemotherapy indicate a good response, while rising levels flag disease progression or recurrence. This allows for timely changes to a patient’s treatment plan. Liquid autopsy is being used to monitor patients with cancers like colorectal and lung that often recur. Recent studies found ctDNA monitoring detect cancer relapse several months before standard imaging tests, enabling swift intervention. Precision oncology clinical trials also use liquid autopsy to gauge if mutations are developing resistance to targeted therapies.
Guiding Therapy Selection
Information from genomic profiling of ctDNA and CTCs helps select optimal targeted therapies and immunotherapy options for patients. Mutations detected in liquid biopsies that predict responsiveness or resistance to specific treatments guide physicians in choosing most effective drugs. For advanced cancers, liquid autopsy can identify new targets as the disease evolves, enabling switching to alternative precision medicines. Meanwhile clinical trials explore using mutation detection in liquid biopsies to select cancer patients most likely to benefit from immunotherapies and tailored drug combinations upfront.
Challenges and Limitations
Despite promising results, some challenges remain for wider clinical adoption of liquid autopsy. CtDNA levels can be low, especially at early disease stages, posing detection difficulties. Sample handling and processing must also minimize contamination from non-tumor DNA to yield accurate results. Further research aims to improve test sensitivity. Standardization of liquid autopsy methods and interpretation of results across laboratories is another area of ongoing work. Larger prospective studies are still needed to fully validate clinical utility. While liquid autopsy may non-invasively cover multiple tumor sites, a tissue biopsy remains important for molecular analyses like PD-L1 quantification required for immunotherapy selection. Overall liquid autopsy is a rapidly evolving field but must overcome certain technical and evidence gaps before becoming a routine part of cancer care.
Future Outlook
With continuous advancements, liquid autopsy looks set to transform how cancer is managed. Beyond its current applications, liquid autopsy may one day detect cancer even before a tumor is clinically apparent, using molecular alterations as an early warning sign. Looking further ahead, it could enable non-invasive cancer screening for entire populations using blood tests done annually or more often.
Liquid biopsy also aims to offer a complete picture of cancer evolution through serial profiling that unveils tumor adaptations to treatments over time. While undergoing continual refinement, the promise of liquid autopsy as a minimally invasive window into the ongoing dynamics of a patient’s cancer makes it a frontier technology in oncology with great potential to benefit those affected by this disease.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
