Sorting Cell-Free DNA by Length May Increase Tumor Detection

There are “subtle but distinct” differences in the length between normal cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA), according to a study published July 18 in PLoS Genetics. Exploiting the consistently shorter fragment length of ctDNA may improve the sensitivity of liquid biopsy testing, the authors say. “This development has the potential to enable earlier detection of solid tumors through a simple blood draw by substantially improving our ability to detect very low quantities of circulating DNA derived from tumor cells,” says lead author Hunter Underhill, M.D., Ph.D., in a statement. “It’s possible that jump in sensitivity could make the difference between being able to detect a cancer, and not.” While the prospect for noninvasively detecting and monitoring cancer is exciting, the clinical utility of liquid biopsies has been limited by its sensitivity, particularly in detecting ctDNA from nonmetasticized solid tumors. Detecting ctDNA against the abundant backdrop of normally occurring cfDNA derived from healthy cells has been likened to detecting a needle in a haystack. However, researchers are working on developing novel approaches to improve detection of ctDNA, including assessing differences in fragment length between healthy cfDNA and ctDNA. Underhill and colleagues utilized massively parallel sequencing to define these […]