Cancer cells may ‘piggyback’ on blood platelets to spread

French scientists have added to the growing evidence that platelets found in the blood may play a role in the spread of cancer cells.

The spread – or metastasis – of cancer cells to other areas of the body is the leading cause of cancer-related death. 

And the findings in mice, from the French Blood Establishment, suggest that targeting particular molecules on platelets may help stop this process. 

Platelets are disc-shaped fragments found in the blood that help stop bleeding after injury. 

A pair of molecules found on the surface of platelets – called integrins – stick to tumour cells in mice and could play a significant role in the cancer spreading, according to the study published in the journal JCI Insight. 

The tumour cells essentially use the molecule to ‘piggyback’ on platelets so they can move around the body. And the research is also the first to show that these molecules allow tumour cells to squeeze out of blood vessels. 

Removing the molecules in mice reduced the spread of cancer cells to the lungs. And blocking the molecules stopped tumours from spreading in mice with breast and skin cancer. 

Professor John Marshall, from the Barts Cancer Institute and a Cancer Research UK expert on how cancer spreads, said: “This is an interesting study. The team discovered that platelets appear to help tumour cells escape blood vessels.

“And if confirmed in patients, then these results could suggest a possible target for drugs to stop cancer cells spreading.

“But at the moment we don’t understand enough about the biology of how cancer cells spread to know when and how such a treatment could be used, and more research is needed to answer these questions.”