Primary tumours can encourage growth of remote cancer cells
New research has found that tumours appear to fuel the growth of stray cancer cells that have travelled to remote parts of the body.
However, a new study by researchers at the Massachusetts Institute of Technology has found that primary tumours are able to mobilise bone marrow cells that then cause these stray cells to develop into secondary tumours.
Publishing their findings in the journal Cell, the researchers revealed that the primary tumour produces a substance called osteopontin, which has previously been found in women with aggressively spreading breast cancer.
Osteopontin leads to changes in the bone marrow that cause bone marrow cells to migrate into the primary tumour. These bone marrow cells then travel around the body and activate dormant cancer cells, causing them to grow into secondary tumours.
The researchers found that stray human breast cancer cells injected into mice only developed into tumours when primary breast tumour cells had also been injected, and that osteopontin is necessary for the process.
Researcher Robert Weinberg, of the Massachusetts Institute of Technology, commented: "We argue they (primary tumours) can foster cancer's spread by activating bone marrow that is then recruited by distant metastases."
He suggested that it could be possible to intercept the signal from the primary tumour to the stray cancer cells and block the spread of cancer.
"That's still speculative, but it's an interesting idea to ponder," he noted.
Importantly, the study shows that primary tumours can encourage the growth of different types of cancer metastases as breast tumours in mice were able to drive the growth of implanted human bowel cancer cells.
The researchers also suggest that this discovery may one day allow doctors to predict how a primary cancer might affect stray cancer cells scattered around the body.