Researchers can predict where cancer cells tend to spread, but figuring out how to trap them has been  tricky. A new device created by engineers at the University of Michigan may help, a study published Tuesday in the journal Nature Communications suggests. 

A new device created by engineers at the University of Michigan may help, a study published Tuesday in the journal Nature Communications suggests.

The mechanism, described as a small, sponge-like implant that captures metastatic cancer cells, could help detect the disease in healthy patients and prevent relapse in survivors, said the engineers who created the device.

“We set out to create a sort of decoy— a device that’s more attractive to cancer cells than other parts of the patient’s body,” study author Lonnie Shea, the William and Valerie Hall Department Chair of Biomedical Engineering at the University of Michigan, said in a news release. “It acts as a canary in the coal mine. And by attracting cancer cells, it steers those cells away from vital organs.”

When cancer cells invade the body, they follow immune cells and try to render them defunct. In mice with breast cancer that were implanted with the decoy, immune cells went not to the organs that cancer cells were preparing to attack but rather to the device itself, as they detected the implant as a more foreign object than the cancer cells themselves. Next, the cancer cells did what they are programmed to do— follow the immune cells. The device caught the cancer cells, preventing invasion in the rodents’ organs. 

Researchers said in the news release that they were surprised to see that the cancerous cells trapped by the implant didn’t combine to form a secondary tumor. Such an accumulation of cells would normally cause damage to surrounding tissue as well, but researchers saw no evidence of that.

“A detailed understanding of why cancer cells are attracted to certain areas in the body opens up all sorts of therapeutic and diagnostic possibilities,” Shea noted in the news release. “Maybe there’s something we can do to interrupt that attraction and prevent cancer from colonizing an organ in the first place.”  

Although researchers have studied only mice so far, they say the device holds promise for application in humans— and not only breast cancer patients, but those with prostate and pancreatic cancer as well.

They wrote in their paper that the device could be implanted under the skin of patients and be used to track cancer cells noninvasively. Engineers at the university are analyzing whether a light-based technology called optical coherence tomography, used with a probe, or ultrasound may be compatible with the implant.

The Food and Drug Administration (FDA) has already approved the sponge-like material that the device is made of. The material is harmless and dissolves in the body over time, and it is particularly effective for the cancer decoy as metastatic cells find it attractive, according to the news release.

Researchers said the device measured about a few millimeters in diameter for the animals, but the one implanted in humans would be slightly bigger than a pencil eraser.