Blood-clot cells could help cancer to spread

PLATELETS, TINY cells that cause blood to clot, can betray their hosts by helping cancer dodge the immune system, new research has shown.

The discovery may explain some of the cancer-fighting properties of aspirin, which thins the blood by blocking platelet activity, scientists believe.

In early mouse studies, a promising cancer immunotherapy was boosted by anti-platelet drugs including aspirin.

Researchers in the US found platelets activate and release a molecule that suppresses cancerfighting T-cells, a key part of the immune system.

The cancer is effectively given an “invisibility cloak” that prevents it being recognised by the T-cells, said the scientists.

The laboratory tests involved giving mice melanoma skin cancer and then a form of immunotherapy that programmes T-cells to target tumours.

Mice survived longer and were less likely to relapse when aspirin and the anti-platelet drug clopidogrel were added to the treatment.

Lead scientist Dr Zihai Li, from the Medical University of South Carolina, said: “I’m very excited about this. We can test simple, over-the-counter anti-platelet agents to really improve immunity and make a difference in how to treat people with cancer.”

The team, whose results are published in the journal Science

Immunity, now plan to test the approach in clinical trials.