A new implantable device could act as a cancer "super-attractor," potentially providing an early warning of relapse in breast cancer patients and slowing the spread of the disease.

The "sponge-like" device attracts cancer cells present in the blood stream during the earliest stages of cancer's recurrence before tumors become visible, the University of Michigan reportedA study of mouse models proved the device attracts detectable numbers of cancer cells before they can be seen in conventional scanning techniques. The findings also revealed cancer spread to the lungs 88 percent more slowly in mice treated with the implants; cancer was observed to spread to the liver and other organs more slowly in these mice.

"Breast cancer is a disease that can recur over a long period in a patient's life, and a recurrence is often very difficult to detect until the cancer becomes established in another organ," said Jacqueline Jeruss, an associate professor of surgery in the U-M Comprehensive Cancer Center. "Something like this could be monitored for years and we could use it as an early indicator of recurrence."

The knowledge that cancer cells don't spread randomly, but are attracted to specific parts of the body paved the way for this groundbreaking new 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," said Lonnie Shea, the William and Valerie Hall Department Chair of Biomedical Engineering at U-M. "It acts as a canary in the coal mine. And by attracting cancer cells, it steers those cells away from vital organs." 

The device utilizes the natural interactions between cancer cells and the body's immune system. Cancer turns the body's immune cells into "drones" that congregate in specific organs and act as "beacons" that attract the cells to the desired location. The team has now described their new implantable device as a "brighter beacon." The new super-attractor draws in the cancer "beacon" immune cells, causing cancer cells to also be drawn in.

"We were frankly surprised to see that cancer cells appeared to stop growing when they reached the implant," Shea said. "We saw individual cells in the implant, not a mass of cells as you would see in a tumor, and we didn't see any evidence of damage to surrounding tissue." 

The researchers are now working to find non-invasive screening techniques that could be used to monitor the device. The technology is still years away from being able to be implanted into humans, but the researchers plan to keep developing it and determining what other types of cancer it could be applied to.

The findings were published in a recent edition of the journal Nature Communications