Liquid biopsy - emergence of a new era in personalized cancer care

Cell free DNA as an evolving liquid biopsy biomarker for initial diagnosis and therapeutic nursing in Cancer- An evolving aspect in Medical Biotechnology

Cell-free DNA (cfDNA) is present in numerous body fluids in addition to initiates generally from blood cells. It is undoubtedly the utmost promising tool among all components of liquid biopsy. Liquid biopsy is a specialized method investigating the nonsolid biological tissue by revealing of circulating cells, cell free DNA etc. that enter body fluids. Since, cancer cells disengage from compact tumors circulate in peripheral blood, evaluating blood of cancer patients holds the opportunities for capture and molecular level analysis of various tumor-derived constituents. Cell free DNA samples can deliver a significant perceptions into oncology, for instance tumor heterogeneity, instantaneous tumor development, response to therapy and treatment, comprising immunotherapy and mechanisms of cancer metastasis. Malignant growth at any phase can outhouse tumor cells in addition to fragments of neoplasticity causing DNA into circulatory system giving noble sign of mutation in the tumor at sampling time. Liquid biopsy distinguishes diverse blood based evolving biomarkers comprising circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) or cfDNA, circulating RNA (cfRNA) and exosomes. Cell free DNA are little DNA fragments found circulating in plasma or serum, just as other fluids present in our body. Cell free DNA involves primarily double stranded nuclear DNA and mitochondrial DNA, present both on a surface level and in the lumen of vesicles. The probable origins of the tumor-inferred portion of cfDNA are apoptosis or tumor necrosis, lysis of CTCs or release of DNA from the tumor cells into circulation. The evolution of innovations, refinement and improvement in therapeutics for determination of cfDNA fragment size and its distribution provide significant information related with pathological conditions of the cell, thus emerging as promising indicator for clinical output in medical biotechnology.

Preanalytic Variables and Tissue Stewardship for Reliable Next-Generation Sequencing (NGS) Clinical Analysis

An enduring goal of personalized medicine in cancer is the ability to identify patients who are likely to respond to specific therapies. Our growing understanding of the biology and molecular signatures of individual tumor types has facilitated the identification of predictive biomarkers and has led to an increasing number of diagnostic tests to be performed, often as serial and distinct assays on limited tumor specimens. The biomarker diagnostics field has been revolutionized by next-generation sequencing (NGS), which provides a comprehensive overview of the genomic profile of a tumor. Many preanalytic variables can influence the accuracy and reliability of NGS results. Standardization of preanalytic variables is, however, complicated by the plethora of specimen acquisition and processing methods. Variables across the tissue journey, including specimen acquisition, specimen fixation, and sectioning, as well as postfixation processing, such as nucleic acid extraction, library preparation, and choice of sequencing methods, are critical for the reliability of NGS analysis; thus, standardization would be beneficial. In this article, each step in the tissue journey is outlined, with specific focus on preanalytic variables that can influence NGS results. Practical considerations for standardization of these variables are provided to facilitate accurate, reliable, and reproducible NGS-based molecular characterization of tumors, ultimately informing diagnosis and guiding treatment.