Cancer metastasis continues to pose difficulties for clinicians. Tumors shed cells which travel throughout the body and attach themselves at distant sites, causing new tumors to sprout. These so-called circulating tumor cells (CTCs) are extremely rare and difficult to pick out from whole blood, in part because they’re often a similar size to white blood cells. While researchers have built various devices that filter out CTCs from whole blood, they have all suffered from either poor performance, high cost, or an inability to capture relevant cellular clusters. Many also end up killing the very CTCs that are captured and needed for further study.
Now, a collaboration between researchers at Worcester Polytechnic Institute, University of Massachusetts Medical School, and University of Louisville School of Medicine has resulted in a tiny device that overcomes these limitations, consistently capturing nearly all the CTCs from a small blood sample and keeping them alive for analysis in the lab.
The chip may make it possible to characterize cancers at an early stage, to monitor their progress, and even allow for the growth of tiny tumors outside the body to study which therapies best work on a given patient’s cancer.
The device features a layer of carbon nanotubes at the bottom of a well within a silicon/glass wafer. CTCs like to stick to carbon nanotubes, but white blood cells are not attracted by them and simply float by.
When tested in the lab on blood samples with a pre-measured number of CTCs, the device demonstrated between 89% and 100% accuracy, depending on how much time it was given. It was also tried with real blood samples from seven breast cancer patients at different stages of the disease, as well as from two healthy adults. The device retrieved the CTCs from all patient samples and returned a negative result on the two healthy samples.
The new chip was able to grab onto CTCs of different phenotypes, which points to it being easily used in a wide range of cancer diagnostic and monitoring applications.
Flashbacks: System Separates, Sequences Circulating Tumor Cells from Whole Blood; New Device Captures Circulating Tumor Cells Directly Within Blood Vessels; CTC-chip Identifies Circulating Tumor Cells in Cancer Patients