Researchers have developed a microfluidic chip that can capture rare clusters of circulating tumor cells, which could yield important new insights into how cancer spreads. The work was funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health.

Circulating tumor cells (CTCs) are cells that break away from a tumor and move through a cancer patient’s bloodstream. Single CTCs are extremely rare, typically fewer than 1 in 1 billion cells. These cells can take up residence in distant organs, and researchers believe this is one mode by which cancer spreads.