Cell-free, circulating tumor DNA (ctDNA) can act as a noninvasive cancer biomarker, offering a potential alternative to invasive tissue biopsies. Today, researchers are investigating the use of ctDNA as a biomarker for detecting the presence of tumors in various cancer types.1 In the future, ctDNA could potentially serve as a noninvasive approach for real-time monitoring of treatment response and identifying candidates for therapy.2
Next-generation sequencing (NGS) offers the sensitivity and specificity needed to detect low levels of ctDNA in the bloodstream. In addition to targeting a single gene or a subset of genes, NGS can also identify genome-wide tumor-derived alterations in ctDNA.
Traditionally, serum-based proteins have been used as cancer biomarkers, but this method has limited utility, as it does not provide information about driver mutations or tumor heterogeneity.1 Somatic mutations in tumor DNA offer a much more specific and accurate biomarker. The advent of NGS and increased knowledge of genomic alterations associated with cancer are making it feasible to identify rare somatic mutations sensitively and accurately.
In the future, ctDNA might play a role in cancer diagnosis, prognosis, and measuring treatment response.