Liquid Biopsies To Find Circulating Tumor DNA

Characterizing and monitoring tumor genomes with blood samples could achieve significant improvements in precision medicine. As tumors shed parts of themselves into the circulation, analyses of circulating tumor cells, circulating tumor DNA, and tumor-derived exosomes, often referred to as “liquid biopsies”, may enable tumor genome characterization by minimally invasive means. In 1948, circulating free DNA (cfDNA) and RNA were found in the human blood plasma by Mandel and Métais.

Liquid biopsy describes the process of extracting a small blood sample from a patient, and screening this for genetic markers that indicate the presence of circulating tumor DNA (ctDNA). With the development of increasingly sensitive sequencing and analysis techniques, researchers are now able to identify tiny fragments of circulating tumor DNA (ctDNA).The ctDNA shed from cancerous tumors contains genetic information that can help stratify patients, monitor treatment progress, and identify emerging resistance. As the concept of precision medicine in the field of cancer management continues to evolve, so too do the challenges and demands with regards to diagnosis, prognosis, and prediction of treatment resistance . Although the discovery of molecular agents able to target specific genomic changes in metastatic cancer patients has revolutionized patient care, tumor heterogeneity remains a daunting obstacle for clinicians who need to optimize therapy regimens based on an individual’s cancer genome. These analyses provide a broadly applicable approach for noninvasive detection of early-stage tumors that may be useful for screening and management of patients with cancer.

By – Assistant Professor – Pratiksha Shahi
Microbiology Department
Uttaranchal (P.G.) College Of Bio-Medical Sciences & Hospital