A simple blood test may be able to provide an early warning of returning skin cancer.
Scientists have identified circulating tumour DNA from two genes linked to the disease in blood samples.
Faulty versions of the genes, BRAF and NRAS, occur in 70 cent of cases of malignant melanoma, the deadliest form of skin cancer.
The disease was much more likely to return within a year of surgery in patients who had either of the defective genes, the researchers found.
Five years after surgery, a third of patients who had the faults were alive compared with 65 per cent of those who did not.
Professor Richard Marais, director of the Cancer Research UK Manchester Institute, who led the research, said: "For some patients with advanced melanoma, their cancer will eventually return. We have no accurate tests to predict who these patients will be, so our findings are really encouraging.
"If we can use this tumour DNA test to accurately predict if cancer is going to come back, then it could help doctors decide which patients could benefit from new immunotherapies.
"These treatments can then reduce the risk of the cancer spreading. The next step is to run a trial where patients have regular blood tests after their initial treatment has finished in order to test this approach."
Professor Karen Vousden, chief scientist at Cancer Research UK, said: "Being able to develop an early warning system that will predict if a cancer will return could make a real difference to patients.
"Research like this shows that for some cancers, there may be ingenious solutions - such as a blood test."
The study is published in the journal Annals of Oncology.
Share
