Cancer cells ‘able to cheat chemotherapy by sleeping’

CANCER cells can avoid being destroyed by chemotherapy by going to ‘sleep’, according to research carried out in Britain.

The cancerous material becomes dormant, making itself immune to powerful drugs, and then ‘awakens’ years later to start growing again.

In some cases tumours can come back even when patients have been free of disease for so long that doctors regard them as cured.

The finding, by the Institute of Cancer Research in London, could pave the way for doctors to work out how to destroy these dormant cancer cells, thus slashing cases of cancer relapse.

The study, published in the journal Leukemia, is unique because researchers had access to blood and bone marrow samples over a two- decade period f rom a patient with a rare f orm of leukaemia.

Researchers analysed samples taken when the patient was diagnosed at four years old alongside samples taken when he relapsed at the age of 25. They identified a specific DNA mutation, in which two genes fused together.

The cells responsible for the relapse are thought to have survived because they were growing much more slowly than other cancer cells – resisting traditional chemotherapy which attacks rapidly dividing cells.

The study gives researchers important insights that might help them root out these cells by ‘waking them up’ so that chemotherapy will kill them.

Study leader Professor Mel Greaves said: ‘Our study shows a common genetic lineage linking the original leukaemia and relapsing disease decades later. It provides striking evidence of cancer evolution in action, with cancer cells able to lie dormant to avoid treatment.’