Liquid biopsy provides several benefits across numerous biofluids such as blood, urine, saliva, cerebrospinal fluid, and pleural effusions. Contrasting traditional tumor biopsies that involve surgical procedures, one of the primary advantages of liquid biopsy is its noninvasive nature. Liquid biopsy necessitates only a biofluid sample, eliminating the need for surgery, anesthesia, related risks, and recovery time associated with traditional biopsies.
“The advent of liquid biopsies has been marked by both optimism and skepticism, necessitating a clear understanding of what these innovative diagnostics can and cannot do. Myths surrounding liquid biopsies could give rise to unrealistic expectations or unwarranted dismissals of their potential,” wrote Ying Bao and coauthors of a review published in Cancer Science .
One prevalent myth is that liquid biopsies cannot detect a comprehensive set of genetic markers as effectively as traditional tumor biopsies. Liquid biopsies have demonstrated considerable efficacy, as tumors continuously shed DNA into various biofluids, not just blood. MicroRNAs (miRNAs) and extracellular vesicles (EVs) are often underestimated but have proven robust diagnostic and prognostic capabilities. These molecules can mirror the tumor’s genetic and molecular landscape, offering valuable information for prognosis, monitoring therapeutic responses, and detecting disease recurrence. This makes miRNAs and EVs valuable complements to circulating tumor DNA (ctD – NA) and circulating tumor cells (CTCs).
The authors emphasized that liquid biopsies are not intended to replace traditional tissue biopsies but to supplement them. Their noninvasive nature allows for continuous monitoring of genetic changes, enabling real-time adjustments in treatment strategies.
However, liquid biopsies are not a universal solution for all cancer diagnostics. Their efficacy varies depending on the type of cancer and its biology. Tumors that shed minimal DNA into biofluids or are in areas with low shedding rates may not be ideal candidates for liquid biopsy. In addition, the use of ctDNA in assessing minimal residual disease is still under investigation, and more research is needed to validate its clinical impact. Early-stage cancers might not release detectable levels of tumorspecific genetic markers into biofluids, posing another challenge.
Liquid biopsies offer substantial benefits but should be applied judiciously within the context of each unique cancer diagnosis.
“Sustained innovation will ensure that liquid biopsy remains at the forefront of precision medicine and proactive healthcare,” the authors concluded.
