ABSTRACT
This chapter provides an overview of contemporary analytical methods and recent advances in applications. The choice of an ideal method for circulating deoxybonucleic acid (DNA) analysis is driven by interplay between technical accuracy, quantitative performance, and allelic discrimination of an assay at any given genomic locus, the type of genomic alteration targeted, and the number of genomic loci assayed. Total levels of cell-free DNA in plasma and serum are elevated in cancer patients. Analysis of circulating tumor-specific DNA (ctDNA) relies on identification, detection, and quantification of these somatic mutations in plasma. ctDNA analysis explores in patients with localized curable cancers. Recent advances in molecularly targeted cancer therapy have improved outcomes in multiple cancer types. Patients are selected for treatment based on the presence of actionable somatic mutations in tumor biopsies. Traditionally, prenatal diagnosis of fetal genetic disorders requires invasive sampling from the fetus, such as amniocentesis and chorionic villus sampling, which are associated with an increased risk of miscarriage.
