Many of these patients take lenalidomide for up to a decade to try to keep their disease under control. However, the blood cancer medicine is not helpful for certain people.
Dr Martin Kaiser, consultant haematologist and clinical scientist at London’s Institute of Cancer Research, said: “A common question they ask is, ‘Do I really have to keep taking this drug?’ and ‘How much is it actually helping me?’”
Worryingly, some studies have suggested that taking the drug for a long time may be associated with an increased risk of some cancers, including Hodgkin lymphoma, but more research is needed in this area.
The new gene test could help distinguish those who can genuinely benefit from lenalidomide and keep their cancer at bay.
The medicine blocks the development of abnormal cells, keeping the cancer in remission for about three years on average, compared to two years without treatment.
“But there’s huge variation – for some it’s a decade, for others a year,” said Professor Kaiser.
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