Scientists at the CRUK Manchester Institute, based at the University of Manchester, have discovered that testing the blood of people with skin cancer for tumour DNA could help predict the chances of an aggressive cancer returning.

The University of Manchester reports the findings, published in the Annals of Oncology, could pave the way to identifying patients who are most at risk of their disease returning, and who might benefit from new immunotherapy treatments.

Led by researchers based at the Cancer Research UK Manchester Institute and the Christie NHS Foundation Trust, scientists studied blood samples taken after surgery from one hundred and sixty one patients with stage two and three melanoma. They then looked for faults in two genes that are linked to 70% of melanoma skin cancers, BRAF and NRAS.

After five years, 33% of people who had a positive blood test for faults in either of the two genes were alive, compared to 65% of those who did not. The results also revealed that skin cancer was much more likely to return within a year of surgery in people who had faults in either of the two genes.

Each year around fifteen thousand four hundred people in the UK are diagnosed with malignant melanoma. Survival rates have doubled in the last forty years, but around two thousand five hundred people die from the condition every year in the UK.

Professor Richard Marais, lead researcher and director of the Cancer Research UK Manchester Institute, based at the University of Manchester, 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, Cancer Research UK’s chief scientist, 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. If follow up research shows that this test can be used to inform treatment decisions and improve outlook, it could be a game-changer in our ability to deal with advanced skin cancer.”