It’s one of the terrible ironies of cancer: The initial tumor typically doesn’t kill a patient. Rather, nomadic cells develop from the growth and attack other critical organs—and that’s what eventually proves fatal. “You can see a specific pattern: Colon cancer cells settle in the liver, but they don’t go to the spleen. So why is that? Why do they go to those particular places?” asks Vadim Backman, a professor in Northwestern University’s biomedical engineering department who is doing the analysis for a new study (along with the primary investigator, Lonnie Shea, a researcher from the University of Michigan). 

In the battle against breast cancer, a small, sponge-like scaffold is helping to answer those questions while proving to be a surprisingly effective weapon itself. Here’s how it works: The implanted device—about the size of a pencil eraser—serves as a decoy. This foreign body replicates the structure of the environment that typically attracts cancer, thereby drawing bad cells to it. Doctors ultimately remove the device, along with the attached cancerous cells. 

Having a big collection of these cells in one place gives researchers a good opportunity to study them and attempt to figure out what exactly makes them metastasize. But in an unexpected side effect, the scaffold also decreases the metastasis of the tumors. In the study, mice implanted with the device had nearly 90 percent fewer breast cancer tumors than a control group. “That was a surprising benefit,” Backman says.

Next comes a human clinical trial, which is in the early planning stages at Northwestern’s Robert H. Lurie Comprehensive Cancer Center. But Backman likes what he saw in the mouse study. “Cancer is very complicated, but the bottom line is, the metastatic tumors don’t grow as much [when the device is present] as they otherwise would,” he says.