Lab on chip device to shed light on how cancer spreads

These rare circulating tumour cells (CTCs) can be found at low levels in a cancer patient’s bloodstream and are thought to be a primary cause of metastasis: the spread of cancer from one part of the body to another.

The new device - which is described in a Nature Methods paper – is expected to enable researchers to capture clusters of these cells and more clearly understand their role in the metastatic process.

The 3-by-1½-inch plastic chip through which a blood sample is passed consists of thousands of triangular microposts arranged in such a way that clusters passing between two posts will become trapped on the apex of a third central post and held in place by the balanced flow of fluid on either side.

Single CTCs and blood cells will pass right through without being captured. In addition, the slow rate at which a sample is passed through the device minimizes the possibility that clusters will be broken, distorted or escape.

Use of the Cluster-Clip to test blood samples from 60 patients with either breast cancer, melanoma or prostate cancer successfully captured CTC clusters in from 30 to 40 percent of samples from each group.

Analysis of captured clusters revealed that they consisted of cells with significant molecular differences, some actively proliferating and other relatively quiescent, and were often accompanied by immune cells, an observation that could have important implications with the increased attention to immune-system-based cancer therapies.

”We are only at the beginning of our quest to understand the role and biology of CTC clusters,” said lead researcher Mehmet Toner, PhD, “Eventually we could develop ways to target clusters therapeutically as well as use them as a source of diagnostic information.”