Liquid biopsy-A biomarker-based revolutionising technique in cancer therapy

Background and AimsCancer has grabbed the attention of scientists and medical professionals all over the world much more than any other disease. In the past few decades, the medical field has improved quite a lot but progress in the path to find a solution for cancer is very less. As the popularity of invasive technologies is diminishing in cancer treatment, scientists have come up withminimally invasive or non-invasive alternatives, among which liquid biopsy, by far is the most suitable.MethodsLiquid biopsy is used to analyse nucleic acids, subcellular components and circulating tumour cells in various biological fluids for diagnosis of cancer. It can also be used to know the efficacy of cancer drugs in a patient by analysing multiple samples.OutcomesLiquid biopsy is becoming standard of care as it allows biopsy of those samples in which solid tumour biopsies are not possible. The diversity of sampling procedures, such as collection of urine for urothelial carcinoma or bladder or prostate cancer and phlebotomy for other types of cancer, make liquid biopsy one of the best methods for diagnosis of cancer.ConclusionThis review aims in discussing the several techniques used for the detection of cancer biomarkers and some clinical manifestations due to the changes in the biomarkers which are analysed by liquid biopsy. Liquid biopsy analyses the levels of biomarkers, which are of clinical significance present in bodily fluids like blood, serum, urine and saliva for diagnosis of cancer. The different biomarkers evaluated by liquid biopsy include cell-free DNA, circulating tumour DNA, non-coding RNA, proteins, exosomes and circulating tumour cells. The biomarkers are analysed using different sophisticated techniques such as microarray, next-generation sequencing, microfluidics, karyotyping, advanced microscopy and fluorescence in situ hybridisation. The biomarkers provide valuable information regarding the stage of cancer and also enlightens medical professionals about the most suitable therapy. image