Washington, A small device implanted under the skin can improve breast cancer survival by catching cancer cells, slowing the development of metastatic tumours in other organs and allowing time to intervene with surgery or other therapies, scientists say.
The finding suggests a path for identifying metastatic cancer early and intervening to improve outcomes, researchers said.
"This study shows that in the metastatic setting, early detection combined with a therapeutic intervention can improve outcomes," said study author Lonnie D Shea from University of Michigan in the US.
"Early detection of a primary tumour is generally associated with improved outcomes. But that's not necessarily been tested in metastatic cancer," said Shea.
"Currently, early signs of metastasis can be difficult to detect," said study author Jacqueline S Jeruss from the University of Michigan Comprehensive Cancer Centre.
"Imaging may be done once a patient experiences symptoms, but that implies the burden of disease may already be
substantial," said Jeruss.
The scaffold is made of FDA-approved material commonly used in sutures and wound dressings. It is biodegradable and
can last up to two years within a patient.
The researchers envision it would be implanted under the skin, monitored with non-invasive imaging and removed upon
signs of cancer cell colonisation, at which point treatment could be administered.
The scaffold is designed to mimic the environment in other organs before cancer cells migrate there. The scaffold
attracts the body's immune cells, and the immune cells draw in the cancer cells.
This then limits the immune cells from heading to the lung, liver or brain, where breast cancer commonly spreads.
"Typically, immune cells initially colonise a metastatic site and then pave the way for cancer cells to spread to that
"Our results suggest that bringing immune cells into the scaffold limits the ability of those immune cells to prepare
the metastatic sites for the cancer cells," Shea said.
In the mouse study at day 5 after tumour initiation, the researchers found a detectable percentage of tumour cells
within the scaffold but none in the lung, liver or brain, suggesting that the cancer cells hit the scaffold first.
At 15 days after tumour initiation, they found 64 per cent fewer cancer cells in the liver and 75 per cent fewer
cancer cells in the brains of mice with scaffolds compared to mice without scaffolds. This suggests that the presence of the
scaffold slows the progress of metastatic disease.
The researchers removed the tumours at day 10, which is after detection but before substantial spreading, and found
the mice that had the scaffold in place survived longer than mice that did not have a scaffold.
The finding was published in the journal Cancer Research.