Parul Gupta
Liquid biopsy is an ingenious innovative technique which has the potential to provide information about cancers without invasive biopsy, using circulating biomarkers. A progressing cancer features heterogeneity and constant evolution, posing a significant challenge to its eradication. Whereas tissue biopsies samples only have a small fragment of the tumour thus capturing a fraction of this heterogeneity, liquid biopsy represents a minimally invasive and more sustainable alternative to interrogate cancer cells longitudinally. All stages of cancer therapy have the ability to benefit from this, starting with screening for cancer before it is clinically apparent. During treatment of metastatic disease, it is advantageous to predict response and monitor disease progression. It involves sampling of non-solid biological tissue, generally blood for isolation of tumour derived components. Circulating tumour cells (CTC), circulating tumour DNA (ctDNA) and eventually other tumour-derived material (e.g. exosomes) alongside existing and new protein markers. In this review, we summarise main techniques and applications of liquid biopsy in oncology.
