Sleeping Cancer Can ‘Wake Up’ Years Later - Drug Discovery and Development

Years, even decades, after remission some cancers return without warning. The “sleeping” cancer cells reactivate, “waking up” decades later, according to a British team of scientists, who say they may have found the molecular key to the change.

A four-year-old patient who supposedly was cured of leukemia developed cancer again at age 25, the researchers said, in their study published today in the journal Leukemia.

Analysis of blood and bone marrow samples taken over 20 years showed a very specific DNA mutation, in which the genes BCA and ABL1 were fused together within the cancer cells, they said. The implication is that cancer cells had resisted chemotherapy by becoming dormant, they said.

“We have always known that in rare cases leukemia can relapse when it appears to be cured, but what we’ve lacked is firm evidence that cancer cells can lie dormant for long periods of time,” said Mel Greaves, the director of the Centre for Evolution and Cancer at The Institute of Cancer Research in London. “Our study shows a common genetic lineage linking the original leukemia and relapsing disease decades later.”

The sleeping cells are thought to have been slower-growing cancer varieties – which were immune to the traditional chemotherapies, which attack rapidly dividing cells, they said.

The new finding could provide clues to cancer adaptations that beat traditional therapies, the scientists added.

“It provides striking evidence of cancer evolution in action, with cancer cells able to lie dormant to avoid treatment, and then to accumulate new mutations capable of driving a new bout of disease,” Greaves added.

The research was funded by Leukemia and Lymphoma Research, with additional support from the European Hematology Association, the Kay Kendall Leukemia Fund and the Wellcome Trust.

The American Cancer Society says that childhood leukemia is extremely rare – but still accounts for a third of all cancers in children and teens. The British scientists said the new finding could be a turning point in beating the worst cases.

“If we can build up a picture of what causes rare cases of late relapse and how we can detect and prevent it, we may be able to deliver more true cures for this terrible disease,” said Matt Kaiser, the head of research at Leukemia and Lymphoma Research.