Potential of the Liquid Biopsy
Understanding somatic mutations (change in genetic structures not passed down from parent cell or inherited by offspring) in tumour tissue is difficult. Historically, challenges in obtaining samples have been mainly due to the procedure being unpleasant for the patient and the process costly.
The other significant problem, that the harvesting of samples cannot be performed over a long-term period, renders accurate monitoring of disease progression information too difficult.
Research into minimally invasive means to collect biomarkers from patients for disease, monitoring longitudinally, is the primary reason behind the drive to ramp up studies into the potential of the liquid biopsy.
Analyzing biofluid in liquid biopsies from clinically relevant samples, still mostly come from blood, plasma, urine and serum material. All analyte classes have advantages and disadvantages. Circulating vesicles that contain biomarkers e.g. microvesicles & exosomes, have the following three advantages:
There is an availability of samples along the disease process
There is stability in ex-vivo samples.
Long-term utility is possible.
Additionally, exosomes and other microvesicles can offer a more thorough picture of a patient's condition than, for example, circulating tumour cells can. That said, the disadvantage remains that it can be difficult to identify the clinically relevant cargo cells due to their diversity and size. Although still considered controversial for some, trials continue to take place and a range of circulating biomarkers continue to be analyzed and appraised for their clinical usefulness.
Enormous interest has been gathering over the past few years into liquid biopsies from both academic researchers and companies wishing to invest and develop a commercially available product that can offer less intrusive diagnostics. More and more movement and activity expected in this fascinating and complex field in the future.