Liquid Biopsy: Opportunities and Expectations

Abstract

Introduction Tumors have an abnormal rate of cell growth and cell division. Tumor cells release circulating tumor DNA (ctDNA), cell free DNA (cfDNA), mRNA and 1 microRNA, in the blood and body fluids which are 2 the by-product of tumor cell lysis. Both ctDNA and cfDNA provide valuable information regarding the cancer related mutations, genetic aberrations and 3 presence of cell free Nucleic acid (cfNA). The ctDNA provides information about the primary tumor and its secondaries / metastases. It is these ctDNA that anchor into novel locations and start dividing to 2 develop secondaries of the tumours. Tumor biopsy is an invasiveprocedure in which tissue is excised from a growth and examined under a microscope. However, “Liquid Biopsy” is a relatively newer technique to find and evaluate cancer cells or their products in blood and body fluids that circulate after tumor cell lysis. Historical Aspect for the Use of Liquid Biopsy: The basis of liquid biopsy was the observation made 4 by Ashworth in 1869, where the circulating tumor cells were detected in a patient with tumor secondaries. The metastatic sites also shed tumor cells in the blood stream that could be detected and analyzed. It was after a long gap when scientists realized that the cell free DNA (cf DNA) could be detected, analyzed, and quantified.......................................................................................................................................